Starting Perennial Seeds
Moisture Levels
Obtain a good supply of baggies, one for each seed variety being germinated, and some damp but not soggy vermiculite. Vermiculite is perfect for this task, it holds moisture well and it doesn't rot. A permanent magic marker and seeds round out our list.
Put a handful of vermiculite in each baggy, then put the perennial seeds in the baggy and mix the two together.
Seal the bag so nothing leaks into or out of the bag.
Plant Labels
Write the name of the seed and the date on the plastic bag and then tuck it into the vegetable crisper in the frig. Writing the name on the bag is critical to prevent 1) the bag from being thrown out and 2) the contents from being eaten or fed to the cat.
You might find if you puff a breath of air into the bag and twist the top, you'll have a balloon type of bag that is perfectly hard enough for writing with magic markers. Collapse the balloon before tying and storing in the frig.
Having the perennial seeds in the frig is the first step in germinating perennial seeds.
Timing Perennial Seeds
Now, as gardeners, we wait. That's the hardest part of all so once a week, pull out every bag and check to see if the seed has started to germinate. Some perennial seeds are known as cool germinators eg. primula, and these will actually start to grow in the baggie. It only takes a few weeks to get these cool germinators started so check weekly after the first two weeks.
If you see a few roots starting to grow, carefully open the bag, remove the germinated seed and plant in a good quality potting soil.
Three Months
Reseal the baggie back into the frig for further germination. In this way, cool germinators will continue to germinate throughout the entire 3 months the baggies will be left in the produce section of the frig.
It is a good idea not to shake up the baggies if this can be avoided as the tender root radicles will be destroyed if they are bent or bruised by shaking.
Stratification
Seeds that are not cool germinators will often have the need for a period of moist stratification. This word "stratification" is simply another gardening word for staying cool and damp.
Dr. Norm Deno has found that the chemical processes that change in a seed do so at approximately the 90 day mark. If the seed was dormant, after 90 days, a chemical change takes place and the perennial seeds might get themselves ready for growing.
Now We Sow
So, after 90 days we take the seed out of the crisper and spread the baggie contents onto a pot filled with damp potting soil. The first thing to do once the seed is spread is to write up a plant label for the pot. Nothing is so frustrating as to have seed germinating and not remember just what was in the pot. Indelible magic markers on cut up margarine tubs work well as does pencil on popsicle sticks.
Keep this soil out of direct sunlight, slightly damp and reasonably warm.
Want to Kill Your Perennial Seed?
Overheating in direct sunlight can often kill the seed. I don't cover most of the perennial seeds I start this way because the vermiculite does an excellent job of providing the correct moisture level and some perennial seeds like to see light before they germinate.
The really large seeds such as perennial sweet pea or lupin can be covered to make sure the root goes down when it emerges from the seed coat.
An almost perfect way to kill your perennial seed is to put them in the freezer - in the package - dry seed doesn't like freezing.
Most perennial seeds will germinate within the next 90 days. These seedlings can be potted up in their own pot, protected from the direct sun until they have 4 to 6 leaves and then given increasing amounts of sunlight or planted outside if the weather is right for planting.
The Perennial Seed Didn't Germinate
If the seeds don't germinate, there are two options. One, the seed is dead and can be thrown out. Or, two, the seed requires a double cold period to break its dormancy.
This double dormancy requirement is quite common on many alpine perennials so the easiest thing to do is plunge the pot into the ground in the semi shade next to your house. Plunging the pot means sinking the pot up to its rim in the ground but leaving some of the rim showing.
Once the pot is plunged, it can be watered and if necessary weeded, throughout the summer. Weed carefully, make sure what you are pulling out is a weed and not a perennial and when pulling them out, try to disturb the soil as little as possible. Simply leave the pot in the ground for the following winter. It will freeze solid and if any germination is to occur, it will occur in the spring after the seed has had a good long winter rest. If the seed does not germinate after this second winter, throw it out.
This system will work quite nicely on just about any perennial you care to grow. Some of the truly rare plants may be a bit more fussy than that but if you are growing Aquilegia jonesii or Erytrichium nanum, you don't need this column's advice anyway. Just send me some seed.
I've started some rare plum and pear trees from Siberia using the crisper method and it is now my method of choice for the other rare tree and shrub seeds I have started to collect.
Simplest Method of Seed Starting
The simplest method however is to simply sow the seed on the top of a pot of soil, and cover very lightly with potting soil. Label the pot and bury the pot; soil, seed and all in a snowbank to wait for spring germinating. You will be surprised at how many perennials will germinate easily and simply this way. After all, that's what they do in our gardens so why shouldn't they germinate this way in a pot.
I know quite a few specialist rock gardeners that use this method exclusively on their alpine seeds and if the seed doesn't grow the first year, they plunge the pot and let it sit for another winter.
Germinating perennial seeds is relatively easy if you use either of these two methods. Of the two, the baggie and vermiculite is the easiest and the most entertaining.
Friends and family can enjoy themselves immensely while watching the impatient gardener rummage through the refrigerator every few days muttering about plants and flowers. For those corpulently challenged gardeners, it is an excuse to visit the frig - "Hey, I'm only in here checking on my seeds." You might not be believed but it's worth a try.
So is starting your own perennial seeds.
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