How to grow your own wildflower seeds
Think of it as growing your plants for free
Think of it as new plants for free – an endless supply at the drop of a seed. Propagating your own plants from seeds you’ve collected around your cottage saves you money, helps preserve the rich community of native species in your area, and provides an incomparable measure of satisfaction and accomplishment. Each self-raised plant feels like the most miraculous personal success – a green-thumb pat on the back. Indeed, it’s easy to feel kind of smug when all those seedlings are lined up in their pots ready to be launched into full adulthood in your cottage garden, and they’re ready because of you.
As with any aspect of native plant gardening, the key to propagating seeds from the wild is to mimic their natural process: They ripen on the plant, drop, and grow. Okay, it’s a little more complicated than that, but, essentially, you can think of it as “ready, set, grow.”
During rambles in the woods or meadows around your cottage, note the wild plants you’d like to grow. Observe their flowering times (e.g. bloodroot in spring, bergamot in summer, asters in fall) and mark their locations with a stick or a twist-tie wrapped around the stem so you can find them easily when you return for their seed.
After flowering, plants begin to form their seeds – in seedheads, pods, capsules, or fruit – and many are ready to harvest about one month later. Check for these clues to ripeness: When pods or capsules, say of butterfly milkweed or columbine, start to turn yellowish-brown and begin to crack or split open, the seeds are likely ready. Squeeze the pod or break off and shake the capsule, then put the seeds in an envelope or paper bag (coin-collection envelopes or glassine stamp envelopes work well). Don’t use plastic containers such as baggies or film canisters, says Scott Martin, owner of WILD Canada, a native-plant nursery in Wasaga Beach, Ont. “They’re airtight, and seeds need to breathe.”
For species with fluffy seedheads, such as asters, ironweed, and goldenrod, just cut off the heads when they look dry and shake or rub them inside a paper bag; seeds by the hundreds will collect in the bottom. Make sure to label the envelopes or bags right away, particularly if you’re gathering a lot of different species at one time.
Other plants, such as wild geranium, large-flowered bellwort, and jewelweed, require a bit of cunning, as these species actually eject their seeds. (If you listen carefully, you’ll hear a stand of jewelweed “popping” their ripe seed.) To catch these dramatic jumpers, fasten a paper bag loosely around the seed pods when they start to ripen (look for a change in colour).
Some spring-blooming woodland plants, such as mayapple, false Solomon’s seal, and Jack-in-the-pulpit, have their seeds encased in fleshy fruits, which change colour and soften when ripe. Pluck the fruit and soak it in a container of water for a day or two, after which you should discard any that rise to the surface. (These floaters won’t germinate.) Gently mash the rest of the fruit in a sieve, releasing the seeds from the flesh. It’s important that seeds from fleshy fruits don’t dry out, so plant them immediately. Most other species can be stored until you’re ready to plant.
Although you may be tempted to collect all the available seeds, resist the temptation. As Deborah Dale, president of the North American Native Plant Society, says, “We recommend you collect no more than 10 per cent of the seeds from a particular plant.” So, if a flower has 30 or so capsules, for example, take only three of them, and leave the rest for natural dispersal. And of course, adds Dale, “don’t take seeds from endangered or rare plants, or plants with very limited populations.”
Once you’ve got a collection of labelled seeds, it’s a good idea to let them dry in the open air for a few days to lower their moisture content so they’re less vulnerable to disease, then separate the chaff from the seed for easier planting later. Next, consider your storage options. For most native species, it’s safe to store seeds for a winter; if you end up stashing them for a year or more, you’ll have lower rates of germination, but some of the seeds will still be viable. (The exceptions to this rule are seeds in fleshy fruits, which do not store well.) If you choose to store seeds over winter or longer, they’ll need to go through either a cold period or a cold moist period that mimics our natural winter before they can germinate. This process is called cold or cold moist stratification and involves storing seeds in the fridge (in a sealed baggie filled with damp vermiculite) for approximately six to eight weeks before you plan to pot them up for germination.
A more convenient strategy for cottagers is simply to pot the seeds in autumn and leave them outside all winter. (For extra protection, you could bury the pots in the earth, as well.)
If you go this route, use sterilized potting soil, which can be purchased from any nursery; soil from the garden will have lots of weed and other seeds, which, when they sprout, will make it hard for you to identify the desired species. To plant the seeds, scatter them lightly onto the surface of the potting mix and finger-press them down. Cover with a light dusting of potting mix and then gently sprinkle some water on top. A good general practice is to plant seeds to the same depth as their thickness.
You’ll have to cover them with fine wire mesh or other protection to keep out rodents and other small animals, but other than that, there’s not much else you need to do. (Mist the soil after planting, but no other watering is necessary.) The seeds will freeze and thaw and get wet from rain and snow – all those things that happen to seeds in the wild – and then they’ll germinate in spring, when their internal clocks tell them it’s time. Some species, such as trillium, Solomon’s seal, false Solomon’s seal, and bellwort, have to go through two winters or more before they germinate, but they’re the exception, not the rule.
Native-plant gardener Jim Hodgins, the editor of Wildflower magazine, suggests a slightly different method, which has the advantage of not requiring pots but can still be done in fall. “In a semi-shaded area, construct a nursery-bed frame using logs, stones, or bricks to delineate the bed and fill with local soil,” he says. “Plant seeds in a straight line, labelling each row with the name of the species and the date planted. Sprinkle a light covering of soil, then cover the bed with fine wire mesh to deter critters. Water gently until the soil is thoroughly moist.”
Once germination occurs, you should keep the soil moist and protected from full sun and strong winds. It’s best to wait until the plant looks vigorous and well established in its growth (at least a couple of leaves and a strong stem) before planting it out in the garden. For some fast-growing species, such as black-eyed Susans, the seedlings will probably be ready for transplanting by mid-summer. If you’re in doubt, keep your seedlings in their pots or the nursery bed until late summer or early fall, then plant them in the garden. Whenever you transplant, though, it’s important to keep the young plants well watered. You may not see blooms the first season but by the following summer, most native species will reward you with colourful flowers and then go to seed. By that time, you’ll be a propagation expert, ready to begin your seed-starting adventures all over again.
This article was originally published on May 14, 2003