“I bought a package of wildflower seeds and planted them, but nothing came up.” Hmmm. I heard this repeatedly as I sold native plant starts at the Portland Tennessee Farmers Market this year. Let’s get into it!
Wildflower seed mixes are sold at all the big-box stores and at many online retailers, but that term “wildflower” is hardly regulated or specific enough to mean anything meaningful to a buyer. I shopped wildflower seed mixes at several big-box stores and found three important caveats that buyers should consider before you buy that seed mix: (1) the seeds included require stratification; (2) the seeds included aren’t native to the United States and/or Tennessee/Kentucky; (3) the mixes contained vague names, vague ingredients, and combinations of flowers that don’t require the same conditions.
First, stratification. Stratification is a pretreatment that mimics natural conditions, typically that means winter. For example, many mixes contained Rudbeckia hirta or Black-eyed Susan. Black-eyed Susan seeds require stratification. When I’m growing Black-eyed Susans from seed, I mix the seeds with vermiculate and moisten the seed mix. I put that in a resealable bag or container and put it in the refrigerator for 30 days. After the 30 days, I put the seed mix with amended soil in a seed tray to start the seedlings. After there are 2 true leaves (that’s the leaves that grow after the first sprout leaves), I transfer the seedlings to pots. Some seed require 30 days, some 60 days, some 90 days, some repeated cold/warm stratification periods mimicking multiple years.
My customers told me that they planted or scattered the seeds during the spring or early summer, so next year they might get Black-eyed Susans. More likely, the seeds will get wet in the rain and rot or get eaten by a bird or insect. So why does it work in nature? It doesn’t reliably. One Black-eyed Susan might have a 1,000 or more seeds in its flower heads. Thousands of seeds turn into a few Black-eyed Susans. Black-eyed Susan seed heads fall and seeds scatter or are scattered via bird droppings in the fall. Some land in protected places under leaf litter and eventually drop to the ground and sprout. Some land close to the plant that produced the seed head (likely in home landscapes) and are protected by the plant itself and sprout in the spring. But most don’t sprout at all. You may think you’re looking at 100s of seedlings in the spring, but it’s probably in the 10s, and that’s from 1,000s of seeds.
Second, the mixes contained non-native seeds. If your intention is to support our local biomass of insects that have co-evolved with our native wildflowers, wildflower mixes are not the way to go. One variety or another of cosmos was common in these mixes. Cosmos species (all of them) are native to Mexico. They grow here, and they sprout from seed easily and reliably. Cosmos are annuals, but they will self-seed, so you can see them year to year. Plus, non-specialist bees will visit a cosmos bloom, so you’re lulled into thinking you’re doing this great thing for our ecosystem. This is tragic for our specialist bees and butterflies, because the space taken by non-native cosmos is space that could have been dedicated to native wildflowers that will support specialist native insects, as well as the generalist species. Many of these specialist insects are suffering terrible population declines, a topic for another day.
The seed mixes also included Queen Anne’s Lace (the white flower in the picture), a flower native to Europe; Chinese Forget-Me-Not, a flower native to Asia; Red Poppy, a flower native to Asia and Africa; Dianthus (Pinks), a flower native to Europe, Asia, and Africa; Marigolds, a flower native to Central and South America; and on and on. One mix I looked at only contained 3 seed types of 16 that were native to the United States. One package contained Crimson Clover. It’s a European and Asian flower that spreads aggressively. If that plant gets going, the Butterfly Weed in the package might as well be inert matter.
Third, the packages themselves were misleading. Some didn’t list the wildflowers included at all. I was able to find the list online though. None said how many viable seeds were in the package. One did say that a little over half the package was inert matter. This isn’t necessarily a bad thing – helps you scatter the seeds widely – if, and it’s a big if, the inert ingredients are the same size and weight as the seeds so it can be effectively mixed. The planting instructions varied as well. Most offered no information about when to expect seedlings. One said 30 days and one, the most realistic of the bunch, said 2 months. How many people buy a seed package thinking they’ll need to “evenly water” for 2 months before they’ll see a sprout? I’m betting it’s not many.
Some of the packages used common names only, no scientific names. This is especially problematic in the wildflower world because common names vary and overlap. Plus, you don’t know whether you’re talking about a straight species plant or a cultivar. When I buy a package of native seeds from a reliable native seed supplier, say Roundstone Native Seed Company, the package offers the common name, the scientific name, and the number of seeds. If that mix you bought lists Rudbeckia hirta (Black-eyed Susan) and contains about 12 Black-eyed Susan seeds, your chances of a Black-eyed Susan sprouting are pretty small.
Growing our native wildflowers can be a challenge and many seed companies are not trying to help you make good decisions for the ecosystem you’re working to build in your yard. Don’t be fooled by the term “wildflower.”
Finally, none of the packages contained the number one keystone native plant for our region, according to the National Wildlife Federation. Here at the Tennessee/Kentucky border, we’re in the Eastern Temperate Forests - Ecoregion 8, and our number one keystone species for supporting specialist insects is Solidago or Goldenrod. There are lots of varieties of Goldenrod from the 8-foot tall gigantia to the 1-foot tall nemoralis. So, if you’d like to support our ecosystem, buy a package of goldenrod seed.
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