1. Recipe for Growing
High Quality Seed
Jodi Lew-Smith, Ph.D.
High Mowing Organic Seeds

2. What will I talk about today?
• OVERVIEW OF SEED QUALITY – what it
means and how to evaluate your own
• OVERVIEW OF GENETIC PURITY – a separate
but equal topic with respect to seed quality
• SPECIFICS on seed production in the
Northeast (this is where the pictures come
in – so be patient!)

3. WHAT DO WE MEAN BY QUALITY
SEED?
• Germinates at or above a defined minimum
germination – usually 85% for vegetable
seed, 75% for flowers and herbs
• Germinates:
– quickly
– with strong vigor
– a full set of seedling parts

4. A quirky and KEY note about seed
quality
The HIGHER the initial germination rate (i.e.
quality), the LONGER the seed will stay
viable
IT’S DIRECTLY PROPORTIONAL!
[And follows, the lower the quality, the more
quickly it dies…]

5. BASIC RECIPE FOR “GOOD SEED”
• Strong fertility
• Good air flow and disease control
• Fully mature at harvest = “finished”
• Harvested as quickly as possible
• Dried as quickly as possible to ~13%
moisture or lower
• Not allowed to get too hot (>85-90°)
during drying
• Stored in cool, dry conditions once dry

6. SAMPLE TESTS FOR FRESH CROPS –
DO THEM IN YOUR KITCHEN!
COUNT CAREFULLY!

7. Evaluating your kitchen germ test
• Anything over 80% is great for a “dirty germ”
• Anything above 50-60% is considered potentially
viable, especially if there is chance of dormancy
and/or immature seed to remove
• The lower the percent, the more cleaning it will
require
• Below 50-60%, you can try to clean the seed to
saleable, but it’s a risk that the labor will be wasted
and a sure thing that the seed will never be high
quality

8. CONSIDERATIONS FOR
GENETIC PURITY
=ISOLATION ISOLATION ISOLATION

9. ISOLATION DISTANCES
• CUCURBITS and other insect-pollinated crops:
MINIMUM OF .5 miles between crops, but ideally
more like a whole mile (size of crop is a factor)
• CORN and other wind-pollinated crops: 1000 feet
between two relatively similar crops, at least 2
miles from GMO
• PEPPERS: 5% outcrossing requires 5-600 ft
• TOMATOES: ~1% outcrossing requires 25-100 ft
(more for potato-leaf types)
• BEANS, PEAS, LETTUCE and other full inbreeders:
no isolation required

10. What if I’m not sure?
• DISCUSS with your seed company
• Have you or your seed company do a GROWOUT of
50-100 plants to look for off-types
NOTE: OFF-TYPES are a big problem for seed
companies because they’re not caught until seed is
grown by customers. They result in recalls!

11. OK WE’RE GETTING TO THE
PICTURES NOW…

12. SEED PRODUCTION IN THE
NORTHEAST: Wet-seeded crops
1. CUCURBITS = “vine crops” =
Squashes, melons, cucumbers
• easy to grow
• Spaced 1-ft for melons, cukes, summer squash
• Spaced 2-ft for all longer-vined crops
• need plastic and row cover to get enough heat
for some of them
• seed quality reliable
• yields highly variable

13. CUCURBIT HARVEST CONSIDERATIONS
= WAIT AS LONG AS POSSIBLE AND HARVEST
BEFORE ROT (OR RIGHT AROUND FROST)
• MOST SQUASHES WILL CONTINUE TO
MATURE SEED IF HARVESTED AND STORED
• SOME LONGER-SEASON SQUASHES WILL
REQUIRE ‘CURING’ IN THE NORTHEAST

14. WINDROWS ARE HELPFUL

15. WET SEED EXTRACTOR

16. SEED COMING OUT OF DRUM

17. Transferring
Seed

18. Washing Seed

19. Seed drying in Greenhouse

20. INITIAL CLEANING
Seed Fractions

21. SEED PRODUCTION IN THE
NORTHEAST: Wet-seeded crops
2. TOMATOES
• plant as early as possible in MAY to get
decent seed yields – needs long days during
flowering
• Spacing usually 18 in.
• Usu. require plastic and spray to grow well
• cherry types always yield better
• quality usually good with good handling
• requires fermentation and defuzzing

22. TOMATO HARVEST CONSIDERATIONS
• HARVEST MULTIPLE TIMES AS FRUIT
RIPENS
• CAN HARVEST PARTIALLY RIPE AND ALLOW
TO RIPEN FURTHER UNDER COVER
• FERMENTATION CRITICAL FOR REMOVING
GEL COAT AND REDUCING DISEASE

26. SEED PRODUCTION IN THE
NORTHEAST: Wet-seeded crops
3. PEPPERS and EGGPLANTS
- Spacing usually 12 inches
- Usually need plastic and row cover – we use
raised hoops (i.e. low tunnels)
- problems with TPB
- Fruit can be harvested partially ripe
- May not have enough heat to mature seed for
all but earliest varieties of bell peppers and
eggplants

27. PEPPER AND EGGPLANT HARVEST
CONSIDERATIONS
• Peppers need to be fully colored but can do this
out of the field and still mature seed
• Need to avoid rot that easily discolors seed
• Need to rinse super well to get off flesh that sticks
to seed
• Need to work quickly once removed from fruit as
seed discolors and loses quality if left sitting wet

29. SEED PRODUCTION IN THE
NORTHEAST: Dry-seeded crops
1. SHORT SEASON CROPS WITH PODS
–
–
–
Brassica rapa = bok choy, mizuna, tat soi, other mild
greens
Brassica juncea = most all the spicy mustards
Brassica oleracea = sprouting broccolis, other quickgrowing oleraceas, mostly Asian types
A few flower species like Cleome, Nicotiana, Sweet
William
–
•
Spacing ranges from 4” to 12” depending on size
of plant frame
•
We transplant them all

30. PODDED SEED HARVEST
CONSIDERATIONS
• We use a ballpark figure of 70% brown as the time
to cut the crop. Earlier and there’s a lot of
immature seed, later and it shatters too much
• Important to get it out of the field in the northeast.
(out west they cure in the field)
• Needs to be as dry as possible before threshing
• Once threshed you can screen out most of the
chaff before beginning to winnow with fans

31. Staked Tat Soi crop 2005

32. CUT AND WINNOWED

33. BROUGHT IN FROM FIELD TO DRY

34. DRYING

35. THRESHING – YES, with a pickup

36. WINNOWING

37. REASONABLY CLEAN SEED

38. SEED PRODUCTION IN THE
NORTHEAST: Dry-seeded crops
2. CORN
• Flint corn is very easy
• Popcorn is feasible, but more commercial
varieties can be very late to mature
• Sweet corn is feasible, but requires
harvesting while still wet and being dried
under high heat to stop fungal progression

39. DRYING
TAKES A LOT
OF SPACE

40. CORN SHELLER

41. Corn seed
typically germs
well and
comes out
pretty clean –
moldy seeds
need handpicking

42. FINISH CLEANING FOR ALL CROPS
TAKES PLACE IN A SEED MILL

43. WHAT MAKES SEED PRODUCTION
WORK FOR PEOPLE?
• Foremost is a passion and dedication to growing
seed.
• Seed growers typically don’t see profits for several
years, so having a dedication to sticking it out
through the learning years is key.
• For brand-new seed growers, our recommendation
is to take a few years “practicing” by growing small
test crops to see how you like it and which crops
work better than others

44. What does and doesn’t work?
• In our experience, it rarely works well to grow commercial seed as a
sideline to commercial vegetables. While it works fine to save your own
seed on a vegetable operation, the higher standards for commercial
quality seed makes it nearly impossible to give the seed crops the
attention they need while simultaneously managing the intense needs
of a vegetable operation.
• Said another way, letting things go to seed under a regime of benign
neglect on a vegetable farm very rarely yields commercial quality seed.
• Likewise, it does not work well to grow a crop for both fresh directmarket sales and also for seed, as the temptation to harvest the best of
the crop for fresh market and leave the remainder for seed is too
tempting. This is the opposite of what we want, as we want the BEST of
the crop for seed.

45. What does and doesn’t work?
• It CAN work well to combine seed production with other farming
ventures that have more similar cycles and equipment. An example is
grains, which are likewise harvested once at the end of a long season.
• One nice thing about seed crops is that seed – if good quality and wellstored – will keep for several years and can be sold over a long window.
• For a small grower with limited isolations for seed, the ability to grow a
large crop of one seed type each year and sell it over several years may
make it feasible to do “off the shelf” sales, which is something seed
companies always appreciate.
• Storage for seed does not need to be fancy – it just requires getting the
seed clean and dry and keeping it that way in a relatively cool place.
(Rubbermaid tubs in a cool cellar can work)

46. One way to break into seed growing:
• Select varieties for your test productions that one or more
of your target seed companies already sell and try to grow
these.
• Before you do so, take a look at the price points and do
some calculating to see if you can think you can grow it for
a price that’s roughly half of the retail price – as this is
typically close to the wholesale price.
• For very common varieties, the going wholesale price can
be quite low because the larger organic seed wholesalers
grow huge productions that benefit from economy of scale.
• Once you have some seed, get in touch with the seed buyer
and let him or her know about it as a “backup” to their
regular supply. If the price at which you’re offering it isn’t
very different from what they’re already paying, they might
be willing to purchase some.

47. A second means to break into seed
growing
• If you have a nice crop of a variety that a seed
company doesn’t sell, the typical process is to get
in touch with the trials manager and provide a
sample of the seed.
• If it does well in trials and you are willing to
continue growing it, the company may well want
to add it to the catalog and buy it from you.
• Seed companies are looking for reliable supplies of
anything they add, so one-time overages are rarely
of interest to them.
• If you’re willing to commit to a variety, a seed
company is more willing to work with you

48. Recent new seed production method
using unheated high tunnels
• Allows BIENNIAL seed production in the Northeast
• Tunnels provide protection on either end of the
season, plus optimizes flowering time
• Opens up possibilities for local organic breeding in
a whole new set of crops
• Opens up possibilities for a new niche crop in
seasonal high tunnels – either as rotation or with
intercropping
• Allows us to grow seed we could never before
grow in New England

49. First commercial cabbage seed crop
in Vermont for at least 100 yrs
APRIL 2013

50. Same crop JUNE 2013
Copenhagen Cabbage June 16, 2013

51. Final yield = 20 lbs at 83% germ
before cleaning

52. Consider using your hoophouse for a
rotation that looks like this!

53. THANK YOU!