An introduction to year round vegetable production; crop planning and record-keeping; feeding the soil using crop rotations, cover crops, compost making and organic mulches; production tips on direct sowing and transplanting, crop spacing, succession crop scheduling to ensure continuous harvests, efficient production strategies, season extension, dealing with pests, diseases and weeds; determining crop maturity and harvest methods.
2. I live and farm at Twin Oaks Community, in central Virginia.
We’re in zone 7, with an average last frost April 30 and average first frost
October 14. Our goal is to feed our intentional community of 100 people with a
wide variety of organic produce year round. www.twinoaks.org
3. What’s in This Presentation
Part 3 - Year Round
Production
Efficient production
strategies
Direct sowing
Transplanting
Crop spacing
Succession crop
scheduling
Season extension
Pests
Diseases
Weeds
Harvest and maturity
Part 4 - Resources
Part 1 – Planning and Record-
keeping
Tools for crop planning
12 steps of planning
Part 2 – Feeding the Soil
Crop rotations
Cover crops
Compost making
Organic mulches
4. Part 1 Planning and Record Keeping
Tools for Crop Planning
• Be clear about your goals (before choosing tools).
• Design a system you like, so you’ll use it.
• Do you prefer clipboards, computers, or photos?
• There are Web-based Tools, Spreadsheets,
Worksheets and Notebooks
• Build in the ability to adapt the plan if conditions
change.
5. Part 1 Planning and Record Keeping
Create Your Own Field ManualThe Fundamental Four
Descriptive month-by-month
Calendar
Field planting schedule
Seedling schedule for greenhouse
production of transplants
Maps of the layout of the crops
Other useful pages:
• Soil Temperatures for vegetable seed
germination
• Days to Emergence at different
temperatures
• Sunrise and Sunset Timetable
• Crop Rotation Plan
• Winter Cover Crops Maps
• Cover Crop Information
• Farmscaping Worksheet
• Other charts and lists from your
planning
6. Part 1 Planning and Record Keeping
Twin Oaks Garden Calendar
• A month-by-month task list describing in words the
tasks to be done each month, including
–Crops to sow, transplant, thin
–Areas to compost and disk or till
–Equipment to check over
–Fruit bushes needing attention
–Crops to harvest
• I’ve posted this on my blog
www.sustainablemarketfarming.com
See my slideshow
Crop Planning for
Sustainable
Vegetable
Production
on SlideShare.net
8. Part 1 Planning and Record Keeping
Planning is Circular - Just Like Farming
1. How much
money do
you need to
earn?
2. Which
markets
to sell at
3.
Which
crops
to grow
4. How much of
what to harvest
when: Harvest
Schedule
5. How much to
grow to achieve
your harvest goals
6. Calculate sowing dates to
meet harvest dates: Field
Planting Schedule7. When to sow for
transplants: Seedlings
Schedule
8. Where to plant
each sowing of
each crop: Maps
9. Packing more in:
succession plantings,
intercropping, relay
planting, double
cropping
10. Adjust to make
your best
possible plan
11. What to do if
something goes wrong:
Plan B
12. Record results
for next year’s
Better Plan
9. Part 1 Planning and Record Keeping Step 5
How Much to Grow
to Meet your Harvest Goals
Take likely yields and add a margin for culls and failures
(10%?). The table I provide in Sustainable Market Farming
lists 48 crops, with likely yield, quantity required for 100 CSA
shares, and length of row needed to grow this amount.
10. Part 1 Planning and Record Keeping Step 6
Harvest Dates Sowing Dates
When to sow to meet the harvest dates?
Find the number of days to maturity (from the catalog).
Is that from seed to harvest or transplant to harvest?
Work back from each target harvest date, subtracting
days to maturity, to give the planting date.
Days to maturity in catalogs are generally for spring
planting once conditions have warmed to the usual range
for that crop.
‒ If you are starting very early, add about 14 days -
seedlings grow slower when cold.
‒ In summer crops mature sooner than in spring.
‒ When growing late into the fall, add about 14 days for
the slowdown.
11. Part 1 Planning and Record Keeping Step 6
Days to Maturity
• “Days to Maturity” usually means “Days to First Harvest” which
may not be the same as “Days to Full Harvest”.
• With carrots it doesn’t matter exactly what size they are, but an
unripe eggplant is just no good.
• With CSAs, you can distribute eggplant to some sharers one week,
and others the next, although keeping track involves more work.
• If it’s important to have a plentiful harvest when you do start, add
another 7-14 days.
Carrot photo Kathryn Simmons
12. Part 1 Planning and Record Keeping Step 6
Field Planting Schedule
Draw up your list of outdoor planting dates, along with
varieties, row feet, spacing, notes and space to write
down what you actually do.
13. Part 1 Planning and Record Keeping Step 7
Seedlings Schedule
Pepper transplants. Photo Kathryn Simmons
14. East Garden
Plots are 9,275-
10,600 ft2
More about this
and crop
rotations later
Part 1 – Planning and Record
Keeping
Step 8 Where to plant each
crop ?
Measure
and Map;
Divide the land
into roughly
equal plots
15. Part 1 Planning and Record Keeping Step 9
Fitting in Summer Succession Crops
After locating the major
crops (including sweet
corn), following our
rotation plan, we look for
any extra space in the
plots, to fit in the
succession plantings of
beans, summer squash,
zucchini, cucumbers,
edamame and
cantaloupes.
Green bean flowers, Photo Kathryn Simmons
16. Part 1 Planning and Record Keeping
Step 9
Succession
Crops Chart
We pencil in arrows,
fitting the succession
crops into the spaces
available.
At the beginning and
end of the season, and
in mid-season when
space in the main plots
is tight, we also look for
spaces in our raised
beds.
17. Part 1 Planning and Record Keeping Step 9 Veg Finder
Example:
Squash #3
WEST Plot J
Plant 6/23
120’
Planted…..
Harvesting…
Finished…..
BEANS CUKES SQUASH CORN CARROTS EDAMAME
#1 29W, 29E
Plant 4/16 180' dbl
Planted
Harvesting
Finished
#1 BED 13W
Plant 4/20 90'
Planted
Harvesting
Finished
#1 BED 23W
Plant 4/20 90'
Planted
Harvesting
Finished
#1 EAST Plot G 4x265’
Plant 4/26+4/29 1060' Bod
Planted
Harvesting
Finished
#1 BED 9E
Plant 2/14 Danvers
Planted
Harvesting
Finished
#1 BED 21W
Plant 4/26 90’
Planted
Harvesting
Finished
#2 EAST Plot G
Plant 5/14 176’ dbl
Planted
Harvesting
Finished
#2 EAST Plot I
Plant 5/24 180’
slice 90' + pickle 90'
Planted
Harvesting
Finished
#2 EAST Plot I
Plant 5/24 88’
Planted
Harvesting
Finished
#2 EAST Plot G 4x265'
Plant 5/21 1060' Bod/KK/SQ
Planted
Harvesting
Finished
#2 BED 25E
Plant 2/28 Danvers
Planted
Harvesting
Finished
#2 EAST Plot G No-soak
Plant 5/18 88’ dbl
Planted
Harvesting
Finished
#3 WEST Plot J
Plant 6/7 240’ dbl
Planted
Harvesting
Finished
#3 WEST Plot J
Plant 6/23 120’
Planted
Harvesting
Finished
#3 WEST Plot J
Plant 6/23 120’
Planted
Harvesting
Finished
#3 WEST Plot A north 4 x 180'
6/6 1080' Sug Pearl /KK/SQ
Planted
Harvesting
Finished
#3 BED 12W
Plant 3/13 Danvers
Planted
Harvesting
Finished
#3 EAST Plot I
Plant 6/7 60’ dbl
Planted
Harvesting
Finished
#4 EAST Plot K
Plant 6/29 175' dbl
(5x35’)
Planted
Harvesting
Finished
#4 CENT Plot D
Plant 7/15 240'
slice 120' +pickle 120'
Planted
Harvesting
Finished
#4 EAST Plot K
Plant 7/15 105’
(3x35’)
Planted
Harvesting
Finished
#4 WEST Plot A 6 x 180'
6/19 1080' Bod/KK/SQ
Planted
Harvesting
Finished
#4 BED 12E
Plant 3/27 Danvers
Planted
Harvesting
Finished
#4 CENTRAL Plot D
Plant 6/26 60’ dbl
Planted
Harvesting
Finished
#5 25E 22W
Plant 7/19 180’ dbl
(2x90’)
Planted
Harvesting
Finished
#5 BED 15E
Plant 8/5 90' slicers
Planted
Harvesting
Finished
#5 BED 13E
Plant 8/5 90’
Planted
Harvesting
Finished
#5 WEST Plot A 6 x 180'
Plant 7/2 1080' Bod/KK/SQ
Planted
Harvesting
Finished
#5 BED 19W
Plant 4/10 Danvers
Planted
Harvesting
Finished
#5 EAST Plot K
Plant 7/14. 70’ (2x35’)dbl
Planted
Harvesting
Finished
#6 BEDS 9W, 9E
Plant 8/3 180’ dbl
Planted
Harvesting
Finished
#6 CENTRAL Plot D 7 x 200'
Plant 7/16 1400' Bod/KK/SQ
Planted
Harvesting
Finished
#6 BED 17W
Plant 5/14 Danvers
Planted
Harvesting
Finished
#8 BED 1 CARROTS#8 BED 30W
Only if needed
Plant 7/8 Danvers
Planted
Harvesting
Finished
#7 Not this year, perhaps never
again
#7 BED 27E
Only if needed
Plant 6/11 Danvers
Planted
Harvesting
Finished
#8 BED CARROTS #9
Overwinter Raised Beds
Plant 7/28 Danvers
Planted
Harvesting
Finished
18. Part 1 Planning and Record Keeping Step 11
What to do if Something goes Wrong: Plan B
Have a brainstorm list to help
deal with disasters:
Do immediate damage control to stop the
problem getting worse
Ask for help from sharers, neighbors, kids,
Salvage anything you can and process it in
some way to sell later.
Plant some quick-growing crops to
substitute for crop failures
Buy from other local growers to tide you
over
Team up with other growers, share a
market booth, save on the rent
Write down what went wrong and why, so
you don’t have the same problem next year
Senposai can be harvested 40 days from
sowing. Photo Kathryn Simmons
19. • Make recording easy to do
• Have a daily practice of writing down what was done that day
• Allow time for that, without losing much of your lunch break
• Delegate to reliable people
• During the main growing season, we don’t do a lot of paperwork.
We record planting dates and harvest start and finish dates.
• At the beginning of the winter, have a Crop Review Meeting, discuss
and write up what worked and what didn’t, to learn from the
experience and do better next year.
• Adjust dates to halfway between last year’s plan and whatever
actually happened - gradually zero in on the likely date without wild
pendulum swings based on variable weather.
Part 1 Planning and Record Keeping Step 12
Record Results for Next Year’s
Better Plan
20. Part 2 – Feeding the Soil
What are Healthy Soils?
• Healthy soils promote plant,
animal, and human health.
• They grow strong plants and
make the conditions unsuitable
for diseases and pests.
• They produce good crop yields,
year after year, without
degrading the environment.
• Sometimes plagues still strike!
Don’t blame the victim!
Tatsoi Photo Wren Vile
See my slideshow
Feed the Soil
on SlideShare.net
21. Part 2 – Feeding the Soil
Healthy Soil is Alive
One acre of organic soil can have 2400 pounds of fungi and 1500 pounds
of bacteria. These contribute to good soil structure, the cycling of
nutrients, and increased levels of organic matter. USDA image
22. Part 2 – Feeding the Soil
Signs of a Healthy Soil
• Has good crumb structure, lets air and water in
and out.
• Resists erosion and compaction.
• Absorbs, holds and releases nutrients.
• Promotes good root growth.
• Provides good habitat for soil organisms.
• Has a moderate pH (6.0 – 7.0).
• Has low levels of salts and toxins.
• Has balanced fertility with adequate levels of
nutrients.
23. Part 2 – Feeding the Soil
Crop Rotations - Many Benefits
Optimize the health and fertility of
the land,
Maximize productivity,
Reduce pests and diseases,
Increase opportunities to plant cover crops,
Meet Organic Certification requirements,
Make the planning work easier on the brain.
See my slideshow
Crop Rotations for Vegetables and Cover Crops
on SlideShare.net
24. Part 2 – Feeding the Soil
Steps to Creating a Permanent Rotation
1. Figure out how much area is needed for each
major crop (the ones needing the largest amount
of space).
2. Measure and map the land available
3. Divide into equal plots each big enough for your
major crops
4. Group compatible crops together to fill each plot
5. Determine a good sequence
6. Include cover crops
7. Include no-till crops
8. Try it for one year, then make improvements
25. Part 2 – Feeding the Soil
Crop Rotations step 1
Space Needed for Major Crops
• Sweet corn: 6 or 7 plantings of about 3,500 ft2 (322 m2) each
• Spring planted potatoes: about 7,000–9,000 ft2 (644–828 m2)
• Summer planted potatoes: about 7,000–9,000 ft2 (644–828 m2)
• Spring broccoli & cabbage: 4,000 ft2 (368 m2)
• Fall broccoli & cabbage: 7,000 ft2 (644 m2)
• Winter squash: about 8,200 ft2 (736 m2)
• Watermelon: about 9,000 ft2 (828 m2)
• Sweet potatoes: about 4,300 ft2 (396 m2)
• Tomatoes: 4,000 ft2 (368 m2)
• Peppers: 2,200 ft2 (202 m2)
• Garlic: about 3,600–4,000 ft2 (332–368 m2)
• Fall carrots: about 3,600–4,000 ft2 (332–368 m2)
26. Part 2 Feeding the Soil
Crop Rotations steps 2 & 3
Make Maps
Divide your land into
roughly equal plots,
each big enough to take
your largest crop
Start filling your map
with your major
crops
remembering crop
rotation
and cover cropping
considerations.
Note the spaces for
squeezing in other
crops
27. Part 2 – Feeding the Soil
Crop Rotations step 4
Group Other Big Crops to Fill Each Plot
Two or three sweet corn
plantings together in one
plot
(3,500 ft2 (322 m2) each)
Spring broccoli together
with overwintered garlic
(4,000 ft2 (368 m2) +
3,600–4,000 ft2 (332–368 m2 ))
Tomatoes together with
peppers
4,000 ft2 (368 m2) +
2,200 ft2 (202 m2)
Left to right: Broccoli under rowcover, garlic,
strawberries.
Photo Kathryn Simmons
28. Part 2 – Feeding the Soil
Crop Rotations step 5
Determine a Good Sequence
To figure out a crop sequence, we looked at the
families of our major crops, and kept crops in the
same family either
• beside each other in the same plot, or
• in plots several years apart in the rotation.
To decide what follows what,
we looked at timing and at
winter cover crops.
29. Winter
Squash
Late Corn
undersown with
oats (1/2). Sweet
Potatoes (1/2)
March-planted
Potatoes, followed
by fall-planted
broccoli & cabbage,
undersown with
clovers
All-year
Green
Fallow
Early Corn
followed by
fall Garlic
(1/2) and
oats (1/2)
Garlic followed
by Carrots (1/2).
Spring Broccoli
& Cabbage,
then rye &
vetch (1/2)
No-till paste
Tomatoes
Water-
melon
Mid-season
Corn, then rye
& crimson
clover
June-
planted
Potatoes
31. Part 2 – Feeding the Soil
Crop Rotations step 8
Improvements
• We tightened up the rotation by
having more than one vegetable
crop in a plot within the year.
• This lets us keep a 10-year cycle
round the 10 plots while having
one plot in cover crops all year
round, to replenish the soil.
• We follow the spring planted
potatoes with the fall broccoli
and cabbage transplanted in
July/August.
• We undersow the fall brassicas
with a mix of clovers, to stay as a
green fallow the whole next year.
Fall broccoli undersown with clover
mix. Photo Twin Oaks Community
32. Part 2 – Feeding the Soil
5 steps of cover crop planning
1. Identify your opportunities for cover crops
2. Clarify your cover crop goals
3. Shortlist suitable cover crops for each
situation
4. Make a decision from among the options
5. Record your decisions and results, and review
for possible changes next year.
Crimson
clover and
bumble
bee.
Bridget
Aleshire
33. Part 2 – Feeding the Soil
Cover Crop Opportunities
Late winter or early spring, if the
area will not be planted with
vegetable crop for 6 weeks (Oats)
In spring, summer or fall, 4 weeks
or more between one vegetable
crop and a later one
Undersowing at last cultivation
(oats and soybeans in corn shown
here.)
In fall, after food crops, for winter
Frost-seeding of small seeds such
as clover: Broadcast in the early
morning when ground is frozen.
As it thaws, the water draws the
seeds down into the soil.
To replace a crop failure.
Year-round cover crops/green
fallow. Photo Kathryn Simmons
34. Part 2 – Feeding the Soil
Cover Crop Goals
• Smothering weeds: sorghum-sudan, cereal rye, buckwheat,
brassicas (we don’t do brassica cover crops – rotation, bugs).
• Fixing nitrogen: clovers, vetches, Austrian winter peas,
cowpeas, soybeans, lentils, sunn-hemp.
• Scavenging leftover nutrients : small grains, brassicas, annual
ryegrass (we don’t use annual ryegrass either – danger of it
becoming a weed)
• Improving soil drainage: sorghum-
sudangrass, sunflower, daikon, sweet-
clover, alfalfa, brassicas, sugar-beet
or forage-beet (never tried that.)
• Grazing
• Bio-fumigation
• Killing nematodes
See my
slideshow
Cover Crops for
Vegetable Growers
on SlideShare.net
35. Part 2 – Feeding the Soil
Plan Good Cover Crops
For early spring food crops, a
preceding cover crop of oats (maybe
with soybeans) is ideal, as it winter-
kills and is easy to incorporate.
Add legumes in mixes with grasses
whenever possible.
Crimson clover, Photo Kathryn Simmons
36. Part 2 – Feeding the Soil
Cover Crops - Oats
For early spring food
crops, a preceding cover
crop of oats (maybe with
soybeans) is ideal, as it
winter-kills and is easy to
incorporate.
Oats need to be sown at
our farm 8/5-9/17 - they
need to follow an early
finishing crop, such as
spring brassicas, spring
potatoes or early corn.
Photo Oklahoma Farm Report
37. Part 2 – Feeding the Soil
Leguminous Cover Crops
Include legumes in cover crop mixes whenever
possible, to add nitrogen to the soil.
For maximum N, mow and incorporate cover
crops when they start to flower. A good
legume stand can provide all the N the
following crop will need. We only spread
compost for our late crops if we had poor luck
with the legumes.
Crimson clover is our favorite clover for over-
wintering. We use it in almost half of our
winter cover crop mixes.
Red clover would also work, but grows less
biomass.
Cowpeas or soybeans are warm weather
legumes. Most cowpea varieties mature in 60-
90 days and will be killed by the first frost.
(Oats may provide temporary protection).
Austrian winter peas can be sown later than
clovers.
Crimson clover flower, Photo
Kathryn Simmons
38. Part 2 – Feeding the Soil
Summer Cover Crops
If we have a 4 week gap
between crops in warm
weather, we sow
buckwheat.
If we have 6 weeks, we
sow soy with
buckwheat.
If longer, Japanese
Millet or
Sorghum-sudangrass
Shown here after mowing.
Photo Kathryn Simmons
39. Part 2 – Feeding the Soil
Late Fall Cover Crops
We sow Crimson clover up till 10/14.
After that, we sow Austrian Winter
Peas as late as 11/8 here, with our
later rye and wheat cover crop
sowings.
Winter wheat is easier to incorporate
into the soil
Winter rye can be planted later than
any other cover crop, up to mid-
November here.
Winter rye is the hardiest cover crop.
Hardy to −30°F. It’s only worth
sowing in November if it will have
time to make some growth in spring Austrian winter peas with
winter rye. Photo Cindy Conner
40. Part 2 – Feeding the Soil
No-till Cover
Crops
We plant our paste tomatoes into a
mowed cover crop of winter rye,
hairy vetch and Austrian winter peas.
This reduces inversions of the soil,
and the legumes (if plentiful) can
supply all the nitrogen the tomatoes
need. Tomatoes in hairy vetch
(without added N fertilizer, or
weeding) can out-yield plastic-and-
fertilizer plots by 25%, and out-yield
fertilized bare soil by 100%.
Rye and vetch is best sown here in
early to mid-September, creating
another restriction on which crops
the tomatoes could follow.
Winter rye and hairy vetch. Photo
Kathryn Simmons
41. Part 2 – Feeding the Soil
Compost Making
Compost improves the soil organic matter, humus, and the soil structure.
The effects of compost last longer than cover crops and crop residues, especially
in humid conditions where plant material breaks down rapidly.
Compost adds beneficial bacteria and fungi to the soil, which can inoculate plants
against diseases (“induced systemic acquired resistance”). Plants produce
antibodies and other protective compounds before any infection occurs.
Many farms make their own compost, using materials that could otherwise be a
waste disposal problem. Certified Organic Farms must follow Organic rules.
42. Part 2 – Feeding the Soil
Compost is Central to our Soil
Fertility Program.
• One of our businesses is making and
selling tofu. Okara is a high-N by-
product
• We mix in high-C sources: sawdust
(from our hammock-making business)
or woodchips (trade with a neighbor)
• We add food scraps from our dining hall
• and sometimes weeds or crop refuse
from our garden.
• We use the tractor bucket to lift and
turn the piles.
43. Part 2 – Feeding the Soil
Compost is a Long-Term Plan!
Because it breaks down slowly, generally about 10
percent of the nitrogen will remain after harvest for
the next crop (assuming an adequate amount of good
finished compost was used).
Some growers aim to build the soil to a high overall
fertility level, and then maintain that level with
smaller applications of compost each season.
Others aim to apply a consistent amount each year.
Whatever your aim, it is generally agreed that the
occasional shortfall in compost application will not be
too dire if the soil fertility is high from previous
applications.
44. Part 2 – Feeding the Soil
Compost Making is Both
Art and Science
• There are several methods and recipes.
• Hot (aerobic) compost combines 1 to 3 parts high-C
materials with 1 part high-N materials in a 25:1 to 40:1
C:N ratio, and enough water to make the piles damp,
air to keep the bacteria alive.
• The mesophilic stage lasts for the first 2-3 days after
the pile is made. Bacteria which are active at 90°F–
110°F (32°C– 43°C) begin to break down the sugars,
fats, starches and proteins.
For more on compost, see my slideshow
Feeding The Soil on SlideShare.net
45. Part 2 – Feeding the Soil
Hot (aerobic) Compost
• The pile moves into the
thermophilic stage, which
lasts several weeks.
Temperatures in the middle
of the pile can reach 120°F–
150°F (48°C–66°C).
• Thermophilic bacteria
increase, and keep working
as long as decomposable
materials remain available
and the oxygen supply is
adequate.
• Pathogens, weed seeds and
fly larvae are destroyed.
Large-scale compost-turning equipment
46. Part 2 – Feeding the Soil
When the Pile Starts to Cool, Turn it
• Because more oxygen or more water is needed.
• Turning remixes the material - all gets composted.
• Turning prevents the pile from overheating —
above 150°F (66°C), thermophilic bacteria can die
• During turning, add water if needed to keep the pile
damp but not dripping.
Large scale
compost-turning
machinery
47. Part 2 – Feeding the Soil
When the Compost Stops Heating
After the compost materials have all been consumed by bacteria
and the N is converted to nitrates, the pile cools to around 100°F
(37.7°C)
More turning won’t reheat it
The C is now resistant to further breakdown, and the N slowly
becomes available for crops
Leave it to cure for about 30 days, allowing beneficial
microorganisms to move back in. It is then ready to be used.
Large-scale compost
screening equipment
48. Part 2 – Feeding the Soil
Finished Compost
Finished compost ideally has a C:N
(carbon:nitrogen) ratio of 10:1.
If the C:N ratio is greater than about 25:1,
almost no N is available from the compost and
it is unable to mineralize.
Between 16 and 20:1, about 10% of the N is
available.
Even at a C:N ratio of 10:1, only 50% of the N
is available in the near term.
49. Some people worry about using too much compost and the levels of
Phosphorus getting too high. On the other hand:
Steve Moore, a veteran high tunnel grower, uses 12-27 gallons/100 sq
ft.
In his Winter Harvest Handbook, Eliot Coleman recommends
spreading compost at 20 gallons/100 sq ft or 15 tons/acre (8.6 l/m2)
of outdoor raised beds, for each successive crop.
For his hoophouses, he makes a plant and seaweed compost and
applies it at 41 gallons/100 sq ft.
At the MSU student farm, compost is applied before every crop at a
rate of 25 gallons/100 sq ft).
Ben Hartman of The Lean Farm: When establishing new raised beds,
they covered the entire growing area with 8-12" of compost. They
reshape once each year and replenish with an 1-2” of compost if
the soil needs help. Their soil now has 10-12% of OM.
Part 2 – Feeding the Soil
How Much Compost?
50. Part 2 – Feeding the Soil
Growing Compost Materials
• If you have land where you are not growing
food crops and don’t want to improve the soil
by growing cover crops, you can grow
compost crops, to cut and haul to your
compost piles.
• This can be a good way to grow food crops
very intensively in a small area, with the
compost crops growing elsewhere.
51. Part 2 – Feeding the Soil
Organic Mulches
Organic mulches such as
straw, hay, sawdust,
woodchips, tree leaves,
newspaper and
cardboard all add
organic matter to the
soil
Here we are preparing a new strawberry bed
mulched with 2 layers of newspaper and dried
sorghum-sudangrass cut from the plot in the
background. Photo Luke J Stovall
52. Part 3 - Year Round Production
Efficient Production Strategies
See Jean-Paul Courtens and Jody
Bolluyt at Roxbury Farm
www.roxburyfarm.com
Photo Southern Exposure Seed Exchange
Plan ahead for success when growing a
wide range of different crops and
doing many different tasks each day.
Plant similar crops together to
minimize time-consuming switching of
tasks.
Plan roads and paths for your truck or
carts to haul away the bounty.
Break long rows up into manageable
chunks. Don’t ask anyone to haul a
harvest crate more than 100ft. Keep
container weight reasonable.
Get the tools ready before you start.
Make sure there enough knives,
scissors, crates, etc. for everyone
Set containers along the rows when
you arrive. Put full ones near the path.
53. Part 3 - Year Round Production
Make a Harvest Methods Manual
Describe the crop when ready to harvest, the tools needed, the harvesting technique, how to
pack in the field, washing and storing techniques, and how to pack in the barn. Train the crew
on each crop, and have the harvest manual for reference. Include the standards for how many
boxes, heads, etc. an average harvester can harvest in an hour.
See the Roxbury Farm Harvest Manual at http://www.roxburyfarm.com/harvest-manual
54. Part 3 - Year Round Production
Direct Seeding Pros and Cons
Photo Kathryn Simmons
• Pros
– Less work than transplanting
– Less money compared to buying starts
– No need for a greenhouse and
equipment
– Better drought tolerance – roots grow
without damage
– Some crops don’t transplant easily
– Some crops have millions of plants!
(Carrots)
• Cons
– Uses more seed
– Uses more time thinning
– Occupies the land longer
– Maybe harder to get started in cold (or
hot) conditions
55. Part 3 - Year Round Production
Transplanting Pros and ConsPros
• Start earlier than outside, get earlier
harvests
• Start seed in more ideal conditions in
greenhouse, better germination, more fun!
• Easier to care for new seedlings in a
greenhouse
• Protected plants grow quicker
• Select sturdiest plants, compost the rest
• More flexibility if weather turns bad. Plants
still grow!
• Fit more crops into the season
• Use time windows for quick cover crops
• Save on seed costs
Cons
• Extra time caring for the starts
• Transplant shock can delay harvest
• More attention needed to watering new
plants
Photo Kathryn Simmons
56. Part 3 - Year Round Production
Transplant Age and Size
Vegetable Notes Ideal Age at Transplanting
Cucumbers,
melons,
squash 2 true leaves max (maybe less) 3–4 weeks
Watermelons (older is OK) 3–4 weeks
Sweet Corn 3–4 weeks
Tomatoes age is less important 4–8 weeks
Lettuce 4–7 weeks
Brassicas 5 true leaves is ideal 6–8 weeks spring/
3–4 weeks summer
Peppers & eggplant 4 or 5 true leaves, not flowering 6–8 weeks
Onions (spring sown)
& leeks 10–12 weeks
Celery 10–12 weeks
57. Part 3 - Year Round Production
Transplanting Depth
o Deeper planting reduces wind stress on
young plants.
o Plant to the first true leaves - increases
yields of many crops. Often this is deeper
than the plant was in the flat.
o Some plants (tomatoes, sweet potatoes)
grow extra roots along the buried stem.
o But soil is cooler deeper down and this
may not be a good thing for warm-
weather plants. e.g. sweet potatoes and
tomatoes
o So - plant in a shallow horizontal or
diagonal trench. Bury much of the stem in
the soil, increasing the growth of extra
roots and protecting the plant against
wind damage, while keeping the roots in
the warmer soil near the surface.
Photo Kathryn Simmons
58. Part 3 - Year Round Production
Water is Vital for Transplants!
Damp soil is important for transplanting.
Water plants an hour before transplanting, and
again after planting.
In very dry weather, water the field ahead of
planting, either with overhead sprinklers or
drip irrigation right on the planting row. Set
out drip tape with emitters at the chosen crop
spacing, water for 20 minutes before planting,
and then plant directly into the wet spots. No
other measuring is needed.
When setting out a large number of plants,
water every 20-30 minutes, regardless of the
number of plants set out.
Water the transplants the next day, on days 3,
7, 10 after planting, and then weekly after
that.
Photo credit Luke Stovall
59. Part 3 - Year Round Production
Crop Spacing
Yield is related to plant density.
Area per plant is the important bit, not
particular row spacing.
There is a balance point at which the plant
density provides the maximum total yield.
At that density some plants will be too small
to use. That’s taken into account when
calculating yield.
Crop size (do customers want big carrots or
small carrots?)
Disease control (humidity and molds)
Preferred layout (beds with equidistant
plants, or rows).
Ease of cultivation (tractor equipment,
hoes, horses) and irrigation
For large plants such as okra or eggplant, it
makes more sense to plant a single row in a
bed and have the plants close together in
that row, in a “hedge.”
See handout for chart of crop spacings
Photo of Morris Heading Collards by
Kathryn Simmons
60. Part 3 - Year Round Production
Optimal Crop Spacing for Various GoalsCrop Row spacing In-row spacing Notes
Beets 7" (18 cm) 4" (10 cm) For early harvest
12" (30 cm) 1" (2.5 cm) For max total yield (small).
2" (5 cm) for bigger beets
Beans, fava 18" (45 cm) 4.5" (11 cm) For tall varieties.
Beans, green 18" (45 cm) 2" (5 cm) 12" (30cm) × 3" (7.5 cm) gives the same area/plant
Broccoli (Calabrese) 12" (30cm) 6" (15 cm) For equal amounts of heads and side shoots
Cabbage 14" (35 cm) 14" (35 cm) For small heads
18" (45 cm) 18" (45 cm) For large heads
Carrots 6" (15 cm) 4" (10 cm) For early crops, limiting competition
6" (15 cm) 1.5" (4 cm) For maincrop, medium size roots
Celery 11" (28 cm) 11" (28 cm) For high yields and mutual blanching
Cucumber (pickling) 20" (51 cm) 3" (8 cm)
Leeks 12" (30 cm) 6" (15 cm) Max yield of hilled up leeks, average size
Lettuce 9" (23 cm) 8" (20 cm) Early crops under cover
12" (30 cm) 12" (30 cm) Head lettuce
5" (13 cm) 1" (2.5 cm) Baby lettuce mix
Onions 12" (30 cm) 1.5" (4 cm) For medium size bulbs
12" (30 cm) 0.5" (1 cm) For boiling, pickling, kebabs
Parsnips 12" (30 cm) 6" (15 cm) For high yields of large roots
7.5" (19 cm) 3" (8 cm) For smaller roots
Peas, shelling 18" (46 cm) 4.5" (11.5 cm) Can sow in double or triple bands, 4.5" (11.5 cm) apart
Potatoes 30" (76 cm) 9-16" (23–41 cm) Depends on size of seed pieces; small pieces closer
Sweet Corn 30-36" (76–90 cm) 8" (20 cm) Closer than 8" (20 cm) the plants shade each other.
Tomatoes, bush types 19" (48 cm) 19" (48 cm) For early crops
Watermelon 66" (168 cm) 12–24" (30–60 cm) For small varieties. 5–10 ft2 (0.5–1 m2) each
66" (168 cm) 30–84" (76–215 cm) For large varieties. 13–40 ft2 (1.2–3.7 m2) each
61. Part 3 - Year Round Production
Succession Crop Scheduling
• Plan sowing dates for even,
continuous supplies of popular
summer crops, such as beans,
squash, cucumbers, sweet corn;
year round lettuce and winter
hoophouse greens.
• Length of time from sowing to
harvest varies according to
temperature (and day length in
some cases).
• Planting squash once a month will
not provide an even supply.
• Keep records and use information
from other growers in your area to
fine-tune planting dates.
Photo Credit: Kathryn Simmons.
For all the details, see my slideshow
Succession Planting for Continuous
Harvests on SlideShare.net
62. Part 3 - Year Round Production
Approaches to Succession Crop Planning
1. Rough plan: “every 2 weeks for
corn and beans, 3 weeks for
cucumbers, squash, edamame,
4 for carrots and cantaloupes”
2. “No paperwork” methods
3. Sow several varieties on the
same day
4. Plan a sequence of sowings to
provide an even supply, using
graphs
5. Use Accumulated Growing
Degree Days data
Squash drawing by Jessie Doyle
63. Part 3 - Year Round Production
“No Paperwork” Methods
Sow another planting of
sweet corn when the
previous one is 1”–2" tall
Sow more lettuce when
the previous sowing
germinates
Sow more beans when
the young plants start to
straighten up from their
hooked stage
64. Part 3 - Year Round
Production
Sow
Several
Varieties
on One
Day
Use varieties with
different days-to-
maturity sown on
the same day.
We do this with
broccoli, lettuce,
sweet corn.
65. Part 3 - Year Round Production
Make a Graph - 6 Steps
1. Gather sowing and harvest start and
finish dates for each planting of each
crop
2. Make a graph for each crop: sowing
date along the horizontal (x) axis;
harvest start date along the vertical
(y) axis. Mark in all your data. Join
with a line. Smooth the line.
3. From your first possible sowing date
find the first harvest start date.
4. Decide the last worthwhile harvest
start date, mark that.
5. Divide the harvest period into a
whole number of equal segments,
according to how often you want a
new patch.
6. Mark in the harvest start dates and
see the sowing dates that match
those harvest dates
For details of this method see
Succession Planting on
SlideShare.net
67. Part 3 - Year Round Production
Year Round Lettuce Part 1
Photo Credits Kathryn Simmons
The short version - sow
• twice in January,
• twice in February,
• every 10 days in
March,
• every 9 days in April,
• every 8 days in May,
• every 6-7 days in
June and July,
See my slideshow Lettuce Year Round
on www.slideshare.net for a list of
varieties and more
information
68. Part 3 - Year Round Production
Year Round Lettuce Part 2
Photo Kathryn Simmons
• every 5 days in early Aug,
• moving to every 3 days in late
August,
• every other day until Sept 21.
• After that we ease back to
every 3 days until the end of
September.
For harvest from November to
March, we harvest leaves from
September-sown lettuces and
baby lettuce mix, planted in our
hoophouse.
69. Part 3 - Year Round Production
Winter Succession Crops in the
Hoophouse
To provide continuous supplies of salad and cooking greens,
as well as radishes and small turnips, we plan successions of
winter hoophouse crops.
For details, see my
slideshow
Hoophouse in Fall
and Winter on
SlideShare.net
70. Part 3 - Year Round Production
Growing Degree Days
A measure of heat accumulation
can indicate when it’s warm enough to plant tender crops,
or when they might be ready to harvest.
GDDs can also be used to plan dates for succession
sowings.
GDDs reflect actual conditions, rather than simply the
calendar, a method which will not work well now climate
change has taken hold.
For most purposes a base temperature of 50°F (10°C) is
used –roughly the temperature at which most plant growth
changes start to take place. Each day when the temperature
rises above the threshold, growing-degrees accumulate.
71. Part 3 - Year Round Production
Growing Degree Days
Average the maximum and minimum temperatures for the
24 hour period, and subtract the base temperature. Add
each day’s figure to the total for the year to date. This is the
GDD figure.
Wikipedia has a good explanation at
www.en.wikipedia.org/wiki/Growing-degree_day
http://farmprogress.com/mobile-apps has a free mobile
phone app!
Using GDDs to schedule sweet corn plantings
https://extension.udel.edu/weeklycropupdate/?p=6618
Using Heat Units to Schedule Vegetable Plantings, Predict
Harvest Dates and Manage Crops
http://smallfarms.oregonstate.edu/sfn/f11degreedays
72. For details, see
my slideshows
Season
Extension;
Hoophouse in
Spring and
Summer ;
Fall Vegetable
Production;
Cold-Hardy
Winter
Vegetables
on
SlideShare.net
Part 3 - Year Round Production
Season Extension in Every SeasonAdvantages and disadvantages in time and money
Growing earlier crops in spring:
o Choose fast-maturing hardy varieties
o Warm microclimates
o Transplants
o Rowcovers, low tunnels, Quick Hoops, high tunnels (= hoophouses)
Extending the growth of cool-weather crops into summer:
o Learn how to germinate seeds in hot weather
o Shadecloth
o Insect netting to keep bugs off
o Intercropping establishes a new crop in the shade of the old one
Using spring and fall for carrots, beets, broccoli, cabbage, kale,
spinach
Extending the survival of frost-tender crops beyond the first fall
frosts
Growing cold-hardy winter vegetables
73. Part 3 - Year Round Production
Formula to Determine Last Sowing
Date for Frost-Tender Crops
Count back from the expected first
frost date, adding:
• the number of days from seeding
to harvest,
• the average length of the harvest
period,
• 14 days to allow for the slowing
rate of growth in the fall, and
• 14 days to allow for an early frost
(unless you have rowcover).
Zephyr Summer Squash
CREDIT: Kathryn Simmons.
74. Part 3 - Year Round Production
Sustainable Pest Management
4 steps of Integrated Pest Management:
1. prevention (reduce chance of problems)
2. avoidance,
3. monitoring (is action needed?)
4. suppression (using least toxic solution)
Carrot pest damage photo by Jessie Doyle
Zipper spider on tomato, photo by Wren Vile
75. Part 3 - Year Round Production
Sustainable Disease Management
Diseases need
• a susceptible host,
• the presence of a pathogen,
• suitable environmental conditions.
Plant pathogens can be
• soil-borne,
• foliar-borne,
• seed-borne,
• a combination of seed-borne with one of the others.
But don’t blame the victim! Bad things can happen to good
farmers!
See www.sustainablemarketfarming.com for more details of these types. Search for
Biointensive Integrated Pest Management
76. Part 3 - Year Round Production
Sustainable Weed Management
• To be most effective, remove
weeds at their most vulnerable
stage, or at the last minute before
the seedpods explode —ignore
weeds doing little damage.
• Different types: annuals and
perennials; stationary perennials
(docks) and invasive perennials
(Bermuda grass); cool-weather and
warm-weather types; quick-
maturing and slow-maturing types;
“Big Bang” types (pigweed) versus
“Dribblers” (galinsoga, shown here)
• Photo Wren Vile
77. Part 3 - Year Round Production
Harvest and Maturity Indicators
• Size: Cow Horn okra at 5” (others shorter), green beans a bit thinner
than a pencil, carrots at whatever size you like, 7” asparagus, 6” zucchini
• Color: Garden Peach tomatoes with a pink flush. The “ground spot” of a
watermelon turns from greenish white to buttery yellow at maturity,
and the curly tendrils where the stem meets the melon to turn brown
and dry. For market you may harvest “fruit” crops a bit under-ripe
• Shape: cucumbers that are rounded out, not triangular in cross-section,
but not blimps. Sugar Ann snap peas completely round
• Softness or texture: eggplants that “bounce back” when lightly
squeezed, snap beans that are crisp with pliable tips. Harvest most
muskmelons when the stem separates easily from the fruit (“Full slip”).
• Skin toughness: storage potatoes when the skins don’t rub off, usually
two weeks after the tops die, whether naturally or because of mowing.
• Sound: watermelons sound like your chest not your head or your belly
when thumped. Try the “Scrunch Test” - press down firmly on the melon
78. Broccoli
Select blue-green broccoli heads and
harvest them before the flower buds
open, but after they’ve enlarged. We press
down with finger-tips and spread our
fingers to see if the head is starting to
loosen.
Cabbageswhen the head is
firm and the outer leaf on the head is
curling back.
To keep mature cabbage in the ground a
bit longer, twist the heads to break off
some of the feeder roots and limit water
uptake, and they will be less likely to split.
Part 3 - Year Round Production
79. Sweet Corn
• Sweet corn will be ready to harvest
about three weeks after the first
silks appear.
• Corn is ready when the ears fill to
the end with kernels and the silks
become brown and dry.
• An opaque, milky juice will seep out
of punctured kernels.
Part 3 - Year Round Production
80. Determining When to Harvest Garlic
• Garlic is ready to harvest when the sixth leaf down is starting to brown on 50% of the crop.
See Ron Engeland's Growing Great Garlic.
• Harvesting too early means smaller bulbs (harvesting way too early means an
undifferentiated bulb and lots of wrappers that then shrivel up).
• Harvesting too late means the bulbs may "shatter" or have an exploded look, and not store
well.
• Cut across hardneck garlic – airspaces around stem show maturity
See my slide
show Growing
Great Garlic
on
SlideShare.net
Part 3 - Year Round Production
81. Onions
Wait until the tops fall over to harvest, then gently dig up the whole plant and dry.
Leave the dry, papery outer skin on the onion.
Photos by Southern Exposure Seed
Exchange
Part 3 - Year Round Production
82. Resources - Books
The Market Gardener, Jean-Martin Fortier, New Society Publishers
The Complete Know and Grow Vegetables, J K A Bleasdale, P J Salter et al.
Knott’s Handbook for Vegetable Growers, Maynard and Hochmuth
The New Seed Starter’s Handbook, Nancy Bubel, Rodale Books
The Organic Farmer’s Business Handbook, Richard Wiswall, Chelsea Green
Sustainable Vegetable Production from Start-up to Market, Vern Grubinger,
The New Organic Grower, The Four Season Harvest, The Winter Harvest Handbook, Eliot Coleman,
Extending the Season: Six Strategies for Improving Cash Flow Year-Round on the Market Farm a free e-
book for online subscribers to Growing for Market magazine
Sharing the Harvest, Elizabeth Henderson and Robyn Van En
Gardening When it Counts, Steve Solomon
Grow a Sustainable Diet: Planning and Growing to Feed Ourselves and the Earth, Cindy Conner,
(worksheet based). DVD/CD set Develop a Sustainable Vegetable Garden Plan
Crop Planning for Organic Vegetable Growers, Daniel Brisebois and Frédéric Thériault (www.cog.ca)
Nature and Properties of Soils, fourteenth edition, Nyle Brady and Ray Weil
Garden Insects of North America, Whitney Cranshaw
SARE Crop Rotations on Organic Farms, A Planning Manual, Charles Mohler and Sue Ellen Johnson,
editors.
Market Farming Success: The Business of Growing and Selling Local Food, Lynn Byczynski
High-Yield Vegetable Gardening, Colin McCrate and Brad Halm, Storey Publishers
How to Grow More Vegetables, John Jeavons. Has charts: Pounds Consumed per Year by the Average
Person in the US and Average US Yield in Pounds per 100 Square Feet.
83. Resources - General
ATTRA attra.ncat.org Market Farming: A Start-up Guide, Plugs and Transplant Production for
Organic Systems, Scheduling Vegetable Plantings for a Continuous Harvest, Intercropping
Principles and Production Practices (mostly field crops, but the principles apply to vegetable
crops), Season Extension Techniques for Market Farmers, and many other great publications.
SARE sare.org -A searchable database of research findings. Available to download: Using
Cover Crops Profitably and Crop Rotations on Organic Farms, A Planning Manual
articles.extension.org/organic_production and https://eorganic.info/ The organic
agriculture community with eXtension. Publications, webinars, videos, trainings, support.
Growing Small Farms: growingsmallfarms.ces.ncsu.edu Click Farmer Resources.
The Center for Environmental Farming Systems at North Carolina State University has good
information on compost-making, such as Composting on Organic Farms.
Compost recipe software is available from Cornell University
www.cfe.cornell.edu/compost/science.html
Southwest Florida Research and Education Center, (All about transplants)
https://swfrec.ifas.ufl.edu/ or https://swfrec.ifas.ufl.edu/programs/veg-hort/transplant/
www.imok.ufl.edu/programs/vegetable-hort/research-extension-ozores/veg-transplant/
Jean-Paul Courtens , Roxbury Farm roxburyfarm.com/ . Regenerative Farming Practices tab:
Soil Fertility Practices; Biodynamic Practices; Whole farm Approach; Harvest Manual; Crop
Manual; Purchasing Equipment; Crop Plan for a 100 Member CSA, including a CSA Share List,
Greenhouse Plan, Field Plan (with charts of possible crop yields).
Growing for Market magazine www.growingformarket.com
84. Resources – My Slideshows
Many of my presentations are available at https://www.slideshare.net/
Search for Pam Dawling. If that doesn't work, search my name, name of
slideshow and "slideshow"
Cold-hardy Winter Vegetables
Cover Crops for Vegetable Growers
Crop Planning for Sustainable Vegetable
Production
Crop Rotations for Vegetables and Cover
Crops
Diversify your Vegetable Crops
Fall and Winter Hoophouses
Fall Vegetable Production
Feeding the Soil
Growing Great Garlic
Growing Sweet Potatoes from Start to Finish
Hoophouse Production of Cool Season Crops
Lettuce Year Round
Many Crops, Many Plantings, to Maximize
High Tunnel Production Efficiency
Production of Late Fall, Winter and Early
Spring Vegetable Crops
Season Extension
The Seed Garden: Planning for seed saving
and lots of vegetables to eat
Seed Growing
Sequential Planting of Cool Season Crops in
a High Tunnel (Hoophouse)
Spring and Summer Hoophouses
Storage Vegetables for Off-Season Sales
Succession Planting for Continuous
Vegetable Harvests
Sustainable Farming Practices.
Year Round Vegetable Production
Year Round Hoophouse Vegetables
85. Resources – Other Slideshows
Mark Cain Planning for Your CSA: www.Slideshare.net (search
for Crop Planning)
Planning the Planting of Cover Crops and Cash Crops, Daniel
Parson www.slideshare.net/parsonproduce/southern-sawg
Cover Crop Innovation by Joel B Gruver www.Slideshare.net ;
Cover crops for vegetable cropping systems, Joel Gruver,
www.slideshare.net/jbgruver/cover-crops-for-vegetable-
crops; Finding the best fit: cover crops in organic farming
systems. Joel Gruver, Some overlap with previous slideshow.
www.slideshare.net/jbgruver/cover-crops-decatur
Cultural Practices And Cultivar Selections for Commercial
Vegetable Growers. Brad Bergefurd, Wide scope.
www.slideshare.net/guest6e1a8d60/vegetable-cultural-
practices-and-variety-selection
86. Resources - Planning
• The Twin Oaks Harvest Calendar by Starting Date and by Crop are
available as pdfs on my website
sustainablemarketfarming.com/2013/11/07/growing-for-market-
articles-2/
• AgSquared online planning software: agsquared.com
• COG-Pro record-keeping software for Certified Organic Farms: cog-
pro.com
• Interactive Vegetable Garden Planner, free for 30 days:
motherearthnews.com/garden-planner.
• Target Harvest Date Calculator: (Excel spreadsheet)
johnnyseeds.com/t-InteractiveTools.aspx
• Growing Small Farms: growingsmallfarms.ces.ncsu.edu click Farmer
Resources, Farm Planning and Recordkeeping to download Joel
Gruver’s spreadsheets.
• Mark Cain www.drippingspringsgarden.com under the CSA tab, you
can download their Harvest Schedule.
87. Resources – Detailed Planning
www.Weatherspark.com weather and climate
Tables of likely crop yields
johnnyseeds.com/assets/information/vegetablecharts.pdf.
gardensofeden.org/04%20Crop%20Yield%20Verification.htm two charts, one of
organic crops from The Owner-Built Homestead by Ken & Barbara Kern, one from
California.
Determining Prices for CSA Share Boxes Iowa State U
extension.iastate.edu/agdm/wholefarm/pdf/c5-19.pdf
New England Vegetable Management Guide Crop Budgets
http://nevegetable.org/cultural-practices/crop-budgets
Clif Slade’s 43560 Project: Virginia Association for Biological Farming newsletter
vabf.files.wordpress.com/2013/08/clif-slade-43560-demo-project.pdf.
USDA annual vegetable consumption www.usda.gov/factbook/chapter2.pdf
The Center for Agroecology and Sustainable Food Systems at the UC Santa Cruz
Crop Plan for a Hundred-Member CSA, for a range of 36 crops in its Unit 4.5 CSA
Crop Planning: casfs.ucsc.edu/education/instructional-resources/downloadable-
pdf-files2 or directly at 63.249.122.224/wp-
content/uploads/2010/05/4.5_CSA_crop_plan.pdf
88. Resources – Season Extension
Extending the Season: Six Strategies for Improving Cash
Flow Year-Round on the Market Farm a free e-book for
online subscribers to Growing for Market magazine
Fall and Winter Gardening Quick Reference, Southern
Exposure Seed Exchange,
www.southernexposure.com/growing-guides/fall-
winter-quick-guide.pdf
www.johnnyseeds.com. Growers’ Library, Winter
growing guide
www.motherofahubbard.com Winter Vegetable
Gardening
Solar Gardening: Growing Vegetables Year-Round the
American Intensive Way, Leandre Poisson, Gretchen
Poisson and Robin Wimbiscus, 1994, Chelsea Green