grow your own, nevada! spring 2012: saving seeds from your garden
TRANSCRIPT
Saving Seeds for a Food-Secure FutureHeidi KratschArea Horticulture Specialist
What is a Seed?
OProduct of sexual reproduction
OMaximizes genetic diversity
Genetic diversity is decreasing
O95% of human food needs now provided by just 4 crops: rice, wheat, corn, potatoes.
OIndustrial agriculture focuses on only a handful of cultivars.
O75% of agricultural genetic diversity disappeared in the last century.
Wheat Stem Rust (Ug99)
O First identified in Uganda in 1999.
O Has spread through Africa into the Middle East.
O ~90% of world’s wheat is defenseless against this virulent strain.
Puccinia graminis
The Irish Potato Famine
Panama DiseaseO1950s – ‘Gros
Michel’ – wiped out!
OToday – ‘Cavendish’- it’s dying!
OFuture – do we need a new cultivar?
The Corn Monoculture
Bringing back biodiversity
Diversity is nature’s survival
wild card.
Plant and Save
Seeds!
Step 1: Avoid growing F1 hybrids
OAlmost all corn seed
OMany varieties of cross-pollinated species
OMust buy new seeds every year
Choose open-pollinatedOCome true to typeOThe easiest are self-
pollinated: beans, peas, tomatoes, peppers
OHeirloom varieties – saved through generations of families and neighbors
OHistory goes back 12,000 years!
Step 2: Protect varietal purity
Flower Structure
Definition of Terms
OAnnual, biennial, perennialOPerfect flowerOSelf-incompatibleOImperfect flowersOMonoecious (single house)
plantsODioecious (two houses)
plants
Self-Pollination
Bagging self-pollinators
Bagging flowers on pepper plants
Plants self-pollinate in the bag
Reemay bagsTreated paper bags
Cross-Pollination
Cross-pollination by insects
OCucurbitsOBrassicasOUmbelliferae
Cross-pollination by wind
OCornOSpinachOBeetsOChard
Isolate plants that readily cross-pollinate
ODistanceOTimeOBaggingOCaging
Pollination Cages
OFrame:OWoodOWireOPlastic pipe OMetal tubing
OCovered with:OSpun
polyester cloth (Reemay)
OWindow screen
Alternate Day CagingONeed a
minimum of two cages.
OAlternate days open to pollinators.
Kale and cabbage will readily cross pollinate.
Caging with
pollinators
1
4
2
3
Step 3: Rogue plants for trueness to type
Select desirable characteristics
OVigorOEarlinessODrought
resistanceOInsect resistanceOFlavorOLate bolting in
cool-season crops
Ample population sizeOEspecially
important for cross-pollinating plants.
OSelect a minimum of 6 plants for seed saving.
OMore plants = more genetic diversity
Step 4: Harvest Seeds
Overwintering Biennials
OSeed-to-seed method
vs.OSeed-to-root-to-
seed method
OBiennials include:O Carrot, celery,
parsleyO Beet, chardO Leek, onionO Rutabaga, turnip,
parsnipO Broccoli, kale,
brussels sprouts
Root Cellarin
g
Onions (Allium cepa) Cepa group
OBiennial, self-pollinating
OOverwinter in ground or lift bulbs.
OBulbs – harvest seed first season
OSeed – harvest seed second season.
Don’t wait too long to harvest seed or the seed heads will shatter!
Broccoli (Brassica oleracea)
OBiennial, cross-pollinating (insect)
OWill cross with all other plants of this species.
ODo not eat plants grown for seed.
OUse cold frame, small hoop house to overwinter.
Beets and Chards (Beta vulgaris)
Biennial, cross-pollinated (wind) – bag or cage
Up to 4 feet tall!
Spinach (Spinacia oleracea)Male plant with flowers
Female plant with seeds
Dioecious, annual, cross-pollinating (wind)
Lettuce (Lactuca sativa)
OSelf-pollinating annual
OBolts in response to lengthening days
OHead-lettuce types need to be slit to allow seed stalk to emerge.
O Seeds ripen 12-24 days after flowering
Squash (Cucurbita pepo)Acorn, crookneck, scallop, zucchini
OMonoecious, cross-pollinating (insect) annual
OCut fruit from vine and let sit for 3 weeks or longer before harvesting seed. Male flower Female flower
Pea (Pisum sativum)OSelf-pollinating
annualOAllow pods to dry
on the vine.OFreeze pods in
airtight container for 3-5 days to kill weevil eggs. Peas and beans are easy
for beginning seed savers.
Carrot (Daucus carota)OBiennial, cross-
pollinated (insect)OUse seed-to-root-
to-seed method OUmbels can be
left to dry on the plant, or
OCut and air-dry.ODe-bearding is
unnecessary.
Corn (Zea mays)OCross-pollinated
(wind) annualOTassels vs. silksOGrow in blocksOSusceptible to
inbreeding depression
ODry ears on the stalk, or remove and dry under shelter
Step 5: Clean seeds
ODry processing
OWet processingOFermentingORinsingODecanting
Dry processing – threshing, winnowing
Wet processing
ORemove seeds from fruit
OWash and rinse
OAir-dryOFerment –
tomato, cucumber
Tomato seeds must be fermented to remove gelatinous coating.
Fermentation
Step 6: Store seeds
OExcellent storage produces vigorous seeds.
OTwo enemies:OHigh
temperatureOHigh moisture
Long-term storage
OCool, dry conditions
OEnvelopesOMoisture-proof
container or freezerOMust be “very
dry.”
Getting to “very dry”
OFan/air conditioner
OFood dehydrator
OSilica gelOCheck daily
until between 5-7% moisture
Testing for Dryness
OWeigh before and after drying slowly in an oven at low temperature.
OSeed moisture content (%) = fresh seed weight – dry seed weight ÷ dry seed weight × 100%
Long-term storage
OFrozen seeds last up to 10 times longer
OStore in paper envelopes with silica gel “dessicant” for one week.
OAllow frozen sealed jar to reach room temp before opening
Supplies:OSeed Savers
Exchange – www.seedsavers.org
Keep good recordsOKeep a card for
each variety.O Plant and varietyO Source, date
obtainedO Germination %O Date storedO Accession numberO Last year grown
Veggies generally not grown from seed
OPotatoOGarlicOArtichokeOAsparagusOSweet potatoORhubarb
Questions?