I have greatly enjoyed the woodland wildflowers this spring. The masses of bloom beckon us to slow down and wander the woods leisurely and look more closely to see their delicate floral displays. Many are ephemeral – meaning their display is fleeting, and they go dormant when summer heat and drought arrive. Spring ephemerals can also be enjoyed in home gardens. However, do not remove these plants from the woodlands. Wild collecting is often prohibited. It is also likely to be unsuccessful inasmuch as survival is reduced when plants are moved in bloom. Instead, purchase nursery-grown plants, carefully plant and nurture them, and propagate them from your home garden for years to come.
Division (from your own garden or a friends' garden) is the easiest way to propagate these plants. Most woodland wildflowers are not as deeply rooted as prairie wildflowers – so they are easier to dig and divide. The best time to divide the spring blooming woodland species is in summer or fall as they are entering dormancy or when dormant. This will minimize damage because they are not actively growing or blooming. Be sure to replant the divisions as quickly as possible so they do not dry out. Some of them, like Dutchman's breeches, have tubers or tuberous root systems that will perish if they dry out before transplanting. Just like dividing any other perennial, water well after dividing. Newly divided plants don't bloom well the first year – so don't expect a bevy of blooms for 2 to 3 years after establishment. Some woodland flowers can be divided every few years. Others will take much longer. Let the plants be your guide on when they are ready to divide – once they are fully established and start to expand a bit you can divide them again.
Wildflowers can also be successfully grown from seeds. Growing plants from seed requires more effort and usually takes longer compared to division. But growing a colony of these beauties from seed is just the sort of challenge many gardeners prefer! Collect seeds when they are mature or ripe. Most woodland wildflower seeds can be collected 4 to 6 weeks after flowering. If you are unsure if the seeds are ripe, collect them in small batches a week or two apart. This may increase your chances for success.
Many woodland wildflowers seeds need to be exposed to cool, moist conditions (stratification) before they are capable of germinating. Winter weather naturally provides these conditions for seeds in the soil. Home gardeners can also stratify seeds by planting them in moist potting soil and storing them in a cool location (such as a refrigerator) for 30 to 60 days. A few of our woodland natives have a hard seed coat that must be broken down by passing through the digestive tract of animals, alternating freezing and thawing or other means prior to germination (scarification). Some seeds of woodland natives are "double dormant" meaning they have two barriers to overcome before germinating. These impediments to germination can be a combination of physical, chemical, environmental, or morphological factors. For example, seed that require more than one winter are considered double dormant. In addition, seed that require both stratification and scarification to germinate are considered double dormant. Finally, some seed have a fleshy pulp surrounding the seed that contains chemicals that inhibit germination – therefore it must be removed prior to sowing for best germination. Remove the pulp by soaking the ripe seeds in water for a couple of weeks. This produces a foul-smelling fermenting mixture – but makes it easy to mash and strain the seeds from the pulp afterward.
Knowing which seed requires which type of pre-treatment requires a bit of research, but is important for best germination. For example - spring beauties and Dutchman's breeches require a warm period prior to the cold stratification which is then followed by another warm period for germination. Even more difficult are trillium seeds, which require multiple cycles of cold and warm periods – sometimes taking 7 or 8 years to germinate. For this reason – most experts suggest sowing seeds of woodland wildflowers immediately after harvest in a dedicated "nursery area" and being patient while Mother Nature does all the work. Sow seed in flats or level beds outside in a part-shade, protected area of the landscape. Keep this "nursery area" maintained (moist and weed free) for a couple of years – as it may take that long to germinate and grow seedlings to a size large enough to transplant.
It is rewarding to grow and nurture your own woodland wildflower garden. The references below will provide more information on growing and propagating these species.
New England Wild Flower Society Guide to Growing and Propagating Wildflowers of the United States and Canada by William Cullina (2000)
Herbaceous Perennial Plants by Allan Armitage (2008)
Making More Plants by Ken Druse (2012)
Prairie Moon Nursery website (www.prairiemoon.com)
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