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Posts Tagged ‘Genetic variation’

Perennial Sweet Peas Seeds need Cold Stratification to Germinate!

Some seeds, like Pansies or perennial Sweet Peas, need special treatment to be able to break dormancy and germinate! If you have wondered why you have never had luck germinating some plants from perfectly fresh seed, cold stratification may be what is needed!

Susan Patterson, Master Gardener, says stratification sequences may vary: ‘Some seeds require a warm and moist treatment, while others require a cool and wet treatment. Even still, other seeds require a combination of both warm and cool treatments followed by a warm treatment, or a combination of warm and cool moist followed by a dry cycle and warm period to germinate. Knowing what seeds require to break dormancy is critical before beginning any seed stratification project.’ Also some plants require stratification from heat, like from fires, to help expose the seed to air and moisture.

The main requirements of Cold stratification are cold and moist. Depending on where you live, it is best to plant when winter is here to stay. If you plant when it is too warm, the seed coat can break down and you may have little germination.

But if you are starting in early season, soak your seeds 12 to 24 hours and put them in a plastic bag or sealable container with sand, peat, or equal amounts of sand and peat. Date and label. Check frequently to see if they are sprouting. Some seeds require a longer period; some need to be in the freezer!

Pinetree Garden Seeds says: ‘Soaking them in cold water for 6-12 hours before starting the process can help cut down on the total stratification time needed. This also helps the seed absorb some of the moisture it requires for the chemical changes that will take place.’

There are different methods, but mainly two.

In the Ground!

1) If your plant reseeds, as soon as it seeds, you can simply broadcast your seed if it doesn’t matter where they come up. Any rowdy ones that come up not in accordance with your garden plan can be transplanted where you might decide you want them, you could give them away, or last resort, eat if appropriate, or compost. I use the broadcast method for Breadseed Poppies. But sometimes you may reroute your garden plan to accomodate what you think will become a lovely display of beauty!

If you have a seed packet, in fall, a more formal version is to decide where you want them, prep that soil, scratch in your seeds. Mark the spot, date and label with a tag. Keep them moist; they will come up when they are ready.

The dangers of these two plans may be floods or wildly fluctuating weather, ie cold, HOT, cold. Keep some backup seeds just in case you need them. Then you go to the #2 methods, or you can do both a 1 and a 2 of your choice just in case…

Seed Cold Stratification Paper Towel

In the Fridge or Freezer!

2) You can use the paper towel method. Moisten the towel, put seeds on one side, fold the towel over on them. Put the towel in a plastic bag, zip it closed. Put it in the fridge and wait. Some say to check every 2 to 3 days, remove any that mold. Others say check in 10 days. Some say it may take up to a month or two. If they get brown spots around them or smell musty, they are rotting and should be tossed. But mainly is to keep that towel moist!

If you have a seed packet, here is the lazy gardener’s choice offered by myseedneeds for poppies! ‘We recommend a short cold stratification period of 6 to 12 weeks, though simply storing your seed packets in your crisper drawer for a couple of months is a trick used by gardeners who don’t want to mess with damp paper towels and plastic baggies.’

Seed Cold Stratification in Sand, Peat, Worm CastingsOr…you can presoak your seeds. Pot up sand or peat, or equal sand and peat; add worm castings to help germination. Put in your seeds. Put the pot or container in the fridge, or put the pot ON the ground in a sheltered place or sink it up to the top of the pot on the colder north side of your building! Be sure to keep those seeds moist.

Important Sustainability point from Harold and the Cats of Alchemy: ‘Seeds…won’t come up all at the same time, like the seeds of most cultivated plants are bred to do. Seeds that use cold to germinate are closer to the wild and so have a good reason to stagger their germination – more are likely to survive that way, and you will get more genetic variation. That means there will be a greater likelihood of getting plants that will survive and prosper in your conditions.’

Plants that can prosper from Cold Stratification treatment

Terms like “self-sowing”, “perennial”, “cold hardy”, or “cold stratification” on a seed packet are indicators your seeds may need cold treatment.

Many Common Domestic Flowers, important companion plants: Bachelor Buttons, BreadSeed Poppy, Cosmos and Pansies, Johnny Jump Ups and Violets (edible petals), Sweet Peas, Zinnia are a few.

Wildflowers! Here’s a terrific MAP to select native wildflowers that need cold stratification before planting in spring for your area! American Meadows! Native wildflowers are terrific companion plants that attract native bees! They need to be in your fridge 4 to 5 weeks, so be sure to start early enough for planting time. Your seeds will germinate quicker and grow well. Don’t forget native Milkweed for Monarchs!

Many Common herbs, perennials, also important veggie companion plants and provide food for pollinators: Calendula, Lavender, Rosemary and Sage

Seed Cold Stratification Sapphire Sage, Salvia Farinacea

Sapphire Sage, Salvia Farinacea

Be sure to look up each plant individually to see it’s specific needs, ie length of time and temp. Here’s an example at SFGate for Oriental poppies (Papaver orientale), a perennial. Some poppies grow readily but the Oriental poppies need special treatment!

  1. Place 2 tablespoons perlite or sand in a plastic bag. Moisten it slightly with water, but don’t allow it to become soggy.
  2. Add 1 tablespoon poppy seeds to the bag and mix the seeds with the perlite or sand.
  3. Place the sealed bag in the refrigerator for two weeks. Check it occasionally and provide more water if necessary to keep it slightly moist. Do not allow it to dry out.
  4. Remove the bag from the refrigerator and store it in a cool, dry location for one week. Place the bag back in the refrigerator for two more weeks.
  5. Repeat this cycle of cold and thaw for six weeks to up to three months. Sprinkle the stratified poppy seeds on moist soil in early spring. They will germinate within two weeks when the soil temperature is between 55 and 60 degrees Fahrenheit. [So start your process in plenty of time!]
Cold Stratification is a simple technique that may take a little dedication, but it really pays off!

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Love your Mother! Plant bird & bee food! Think grey water! Grow organic! Bless you for being such a wonderful Earth Steward!

The Green Bean Connection newsletter started as correspondence for the Santa Barbara CA USA, Pilgrim Terrace Community Garden. All three of Santa Barbara city community gardens are very coastal. During late spring/summer we are in a fog belt/marine layer area most years, locally referred to as the May grays, June glooms and August fogusts. Keep that in mind compared to the microclimate niche where your veggie garden is.

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