Overview

The Major Vegetable Families
Amaryllidaceae - Leeks, Onions, Shallots
Brassicaceae - Broccoli, Cauliflower, Cabbage, Kale
Asteraceae - Artichoke, Escarole, Chicory, Cardoon, Jerusalem Artichoke, Lettuce, Sunflower
Cucurbita - Squash, Pumpkin, Gourds
Chenopodiaceae - Beets, Chard, Spinach, Quinoa
Ficus - Fig
Lamiaceae - Basil, Mint, Oregano, Perilla, Rosemary, Sage, Thyme
Poaceae - Bamboo, Corn, Wheat, Oats, Rye

Prunus - Apple, Pear, Peach
Ribex - Gooseberry

Rubus - Raspberry
Solanaceae - Eggplants, Peppers, Potatoes, Tomatillo, Tomato, Tobacco

Planning Your Garden for Seed Saving
Gardening starts with planning. If you want to save seed from your garden, understanding some basic concepts when you are planning your garden will make seed saving much easier.

Know whether your seeds or plants are a hybrid or open-pollinated variety. Hybrids, which are created by crossing plants of two different varieties, generally do not produce offspring with the same traits as the parent plant. Seed saved from open-pollinated varieties, on the other hand, will produce plants identical to the parent. Heirloom seeds are open-pollinated varieties with a history of being handed down from generation to generation.

Know your plants’ scientific name [Genus and species]. Cross-pollination is the transfer of pollen between plants. To save pure seed, you want to prevent cross-pollination between two different varieties in the same species. Planting just one variety in a species will help ensure that you save pure seed.

If you know your plants’ scientific name, you will know which species may cross-pollinate. For example, the squash we commonly grow in our gardens could fall into one of three species: Cucurbita maxima, C. moschata, and C. pepo. These species won’t typically cross-pollinate. Brassica oleracea (broccoli, brussels sprouts, cabbage, cauliflower, collards, kale and kohlrabi) cross pollinate readily.

Know how your plants pollinate. Understanding how garden plants are pollinated will help you prevent cross-pollination. Some plants will self-pollinate before the flower is even open, making them less susceptible to cross-pollination (examples of “selfers” are tomatoes, peas and beans. On occasion, insects can cross-pollinate selfers). Plants that are insect-pollinated (squash or cucumbers) or wind-pollinated (corn and spinach) are more likely to cross-pollinate.

Know what your neighbors are growing. Some varieties, especially those that are wind or insect-pollinated, need a certain distance of isolation to ensure seed purity. For example, sunflowers must be isolated 1/2-3 miles, and corn needs a distance of 2 miles. You may have to consider what your neighbors are growing.

Market mature vs. seed mature. Some fruits are market mature, or ready for eating, long before the seed is mature. Examples of this include cucumbers, eggplants, peas, beans and cabbage. Take into consideration spacing and timing when planning your garden for seed saving. For example, imagine a carrot – you pull this sweet root out of the ground after about 2 months, and there is not much plant showing above ground. However, when you harvest the seed, a carrot plant can be up to 4 feet tall and one year old!

For beginners, keep it simple! Remember, some plants are easier to save seed than others. Saving seed from “selfers” is a good way to get started. Planting one variety per species can unsure your seed has not cross-pollinated. Check out “Seed to Seed” by Suzanne Ashworth, for detailed seed saving information.

Basic Seed Saving Information
Cycle: A= annual; B=biannual
PN = Pollination; S= self; X= cross
PR = Pollinator
ID = Isolation distance
SL = Seed longevity
NA = Not applicable
y= years

Name

Cycle

PN

PR

ID

SL

Notes

Bean

A

S

NA

100’

2-3 y

Seeds lose vigor rapidly

Soybean

A

S

NA

100’

2-3 y

Space further apart than for market crops

Beet/chard

B

X

Wind

½ mi

3-5 y

Beets cross with chard

Broccoli/kale/cauliflower

B

X

Insects

½ mi

3-5 y

Hot water-treated seeds last only 1 yr; crossing among brassicas is complex; consult a seed-saving book

Carrot

B

X

Insects

1500’

2-3 y

Crosses with wild species

Celery

B

X

Insects

1500’

2-3 y


Corn

A

X

Wind

½ mi

2-3 y

Need 200+ plants for adequate population

Cucumber

A

X

Insects

1500’

5-10 y

Harvest at yellow blimp stage

Eggplant

A

S

NA

150’

2-3 y


Leek

B

X

Insects

1500’

2 y


Onion

B

X

Insects

1500’

1 y


Lettuce

A

S

NA

50’

2-3 y

Start indoors; needs long season for seed production

Melon

A

X

Insects

1500’

5-10 y

Muskmelons will not cross with watermelons

Mustard

A

X

Insects

½ mi

3-5 y

Crosses with wild species

Pea

A

S

NA

50’

2-3 y

Do not save seed from diseased plants

Pepper

A

SX

Insects

500’

2-3 y

Some varieties cross more readily than others

Radish

A

X

Insects

1500’

3-5 y


Spinach

A

X

Wind

½ mi

2-3 y


Squash/

pumpkin

A

X

Insects

1500’

2-5 y

Moschata 2-3 y; pep and maxima 3-5 y; these 3species generally don’t cross

Tomato

A

S

NA

25-100’

5-10 y

Potato-leaf types need greater ID

Essential Seed Saving Materials,
Index cards, paper bags, plastic bags, plastic freezer containers, 5-gallon buckets, tarps, mesh strainer, 1/2", 1/4" and 1/8" gauge screens for sifting seeds from chaff (screens can be found in Indian grocery stores).

Suggested Seed Saving Equipment
Excalibur food dehydrator, dry ice

1. Collect dry seeds in paper bags or buckets; do not water plants and then collect damp seeds.
2. Fill out index card with the following information: seed type, harvest date, whether anything else of the same species was growing in your garden, if so, what plant it was and how close, any other information that prompted you to save seed from this particular plant
3. Clean seeds, determine moisture content and transfer to new container with index card for long term storage.
4. Store seeds in a cool (50-72 degrees), dry and dark location.

Seed Storage
Keep your seed alive by storing it properly! Humidity and heat are the enemies of seed longevity. Humidity causes the quickest deterioration. Ideal moisture content for most seed is only 10-12% so store at low relative humidity. Use a sealed jar in your freezer or refrigerator for optimum storage. Once thawed seed must be planted that season. Another method is to store in a cool dark place using desiccant packets to help remove moisture. Don’t ever allow the sum of temperature plus relative humidity where seed is kept to exceed 100.

Never store in a warm, humid sunny spot. Don’t ever leave seed in a greenhouse or hoophouse, even for a few hours.

Stored properly, most seed will last for several years. A few seeds are good for only one year, such as onions, parsnips, parsley, chives, shiso, scorzonera/salsify, Batavian endive, licorice, pennyroyal, St. Johnswort, liatris, delphinium, larkspur, perennial phlox, and any pelleted or hot-water treated seed. If in doubt, try germinating a sample in moist paper towels.
Seeds dried at room temperature have a moisture content of 10-20%. Do not store seeds dried at room temperatures in air-tight containers or in the freezer. Only seeds with a moisture contact of 6-8% should be frozen. Freezing seeds with higher moisture content will damage the embryo and can split the casing.

How can I test for a moisture content of 6-8%?
Large seeds (squash, melons, cucumbers) will snap in half, not bend. Small seeds (beans, kale, collards, peas) will shatter, not mush or mash, when hit with a hammer.

How do I lower moisture content for long term storage?
Seeds can be packed with silica gel until enough moisture has been withdrawn.
Seeds can be dried in a food dehydrator with adjustable thermostat. Set at 95 degrees Fahrenheit for up to 8 hours.
Large amounts of seeds and grains can be dried using dry ice. Crush 3 oz dry ice and mix with 2 inches of seeds/grains in the bottom of a 5-gallon bucket, top off the bucket with remaining seeds/grains, cover loosely for 8 hrs or more to allow dry ice to vaporize. The carbon dioxide, a heavier gas, will displace all oxygen, dry seeds and suffocate any insects. After 8 hours seal container and place in a cool, dry and dark location.