By JIMMY ROGERS
It’s easy to imagine: kill your lawn (or pull out a patch of invasive plants), spread a native seed mix and watch an entire garden spring out of the earth, ready to host birds and butterflies. Recently I’ve been bombarded with online ads promising just this proposition. Friends and clients often ask me whether they can forgo buying plants and throw down a seed mix instead. Let’s untangle the confusing world of native seeds and find some sure-fire options for any garden.
First, we need to winnow out the seed mixes for sale online and at garden centers that native gardeners will want to avoid. Many seed mixes are labeled as wildflower mixes and were around long before native gardening caught on. Typically, they’re composed of popular European and Asian flowers that grow within a range of USDA plant hardiness zones. Sometimes they’re even labeled for a specific state, despite having no relationship to that state’s ecosystem. These plants offer little to our native insects, and sometimes include invasive species in the mix.
A new, trendy product is called a no-mow lawn mix — a blend primarily composed of clovers (Trifolium species) that come from Europe. While some generalist bees will benefit from clover flowers, again, these mixes provide little forage for the majority of our bees and other pollinators. Plus, clover will quickly succumb to taller weeds and have you mowing all over again.
Now that we have skirted around these misleading products, we can return to the hypothetical seed-to-garden scenario I described at the start. Let’s say you have cleared an area of ground, acquired seeds native to Maryland and scattered them. What can you expect?
If you sowed your seeds in the spring, by now I guarantee you would start seeing lots and lots of baby plants emerging. As you would have recently disturbed the soil and told every existing weed seed to spring into action, I would expect a majority of these new plants to be opportunistic weeds. It will be hard to sort the weeds from everything else, though, as almost all baby plants look very similar until they have sprouted their adult leaves.
Another factor weighs in favor of the weeds: Native plant seeds don’t all germinate in the same year, and some have a very low germination rate overall. Even if your seed source stratified your seeds (a treatment that encourages seed germination), many of them will be content to remain dormant in the soil for several years. Delayed germination is an ancient strategy plants have used over time to ensure that a bad year or bad conditions do not thwart all chances of reproduction. Native seed mixes often include annuals such as partridge pea (Chamaecrista fasciculata) so that gardeners will be rewarded with some germination in the first year.
Nursery plants hold a clear advantage over seeds when it comes to survival. Nurseries plant seeds in ideal soil, grow them in ideal conditions and separate them into their own pots. With no competition, each seed has a much higher likelihood of survival. This is especially true for nurseries planting native seeds, which are costly to produce. The seeds you scatter, on the other hand, are an easy meal for predators.
So what good are native seeds to the home gardener? Well, first, you can use seeds the way nature intended, by leaving seed heads on flowering plants to either be eaten by over-wintering birds or to generate new plants throughout your garden. This costs nothing and is the best way to grow more of the plants you already have.
If you’re creating a new garden, buying nursery plants can be expensive, so consider winter sowing. This technique uses an old milk jug and a handful of seeds from a single species to create a miniature greenhouse. You can gather seeds from a generous neighbor’s garden or from one of the many seed savers you’ll meet in the native gardening community. The University of Maryland Extension has an excellent video series, “All the Dirt on Winter Sowing Native Plants,” which you can watch at tinyurl.com/mjv55kpn. You can easily grow hundreds of baby plants for next to nothing.
I do recommend scattering seeds if the seeds will have little competition and the area will not be mowed. A newly planted bed in your own garden meets these conditions. Choose filler plants for the spaces between more robust plants; they’ll reseed themselves readily in the future. You can scatter the seeds of high-germination species like self-heal (Prunella vulgaris) or pickier plants like columbine (Aquilegia canadensis) and butterfly milkweed (Asclepias tuberosa).
Regardless of how you use seeds in your garden, keep a few small paper bags handy so that when your own plants go to seed, you can become the neighborhood’s next seed saver.
