Editor’s note: This story was originally published in February 2024.
It wouldn’t be a Maine summer without native wildflowers, like cardinal flowers, Joe Pye weed and swamp milkweed.
Commonly spotted along road verges and forest margins, shaded streambanks and grassy fields, native wildflowers are staples in the Maine landscape.
But they can also be cultivated in flower beds where they offer unique benefits to gardeners.
Maine native plants are perfectly evolved to handle the fluctuating weather patterns and harsh winters of New England. They require “few inputs like fertilizer and water and [they] are best positioned to thrive as our climate changes,” said Cathy Rees of the Native Gardens of Blue Hill.
Plus, native plants are more than four times more attractive to pollinators than non-native species, and they are essentially “the base of the food chain. They feed the ecosystem,” Rees said.
With all those perks, it’s no wonder why interest in native gardening has been growing. Yet many garden centers still don’t sell native plants, so gardeners often resort to growing their own from seed.
In order to germinate, many native plant seeds require a special technique known as cold stratification.
Cold stratification may sound tricky, but it isn’t. In basic terms, cold stratifying occurs when seeds are kept moist and subjected to a period of cold before temperatures warm up. This tricks seeds into “thinking” they’ve experienced a full winter, spring has arrived and it’s time to sprout.
The simplest method is to plant seeds outdoors in fall and allow them to naturally stratify in chilly winter gardens. But outdoor stratification has its risks and seeds can be lost to mold or gobbled up by scavenging birds and rodents.
Stratifying indoors safeguards seeds from these potential threats and it’s also a handy solution for gardeners who forgot to plant wildflower seeds in autumn.
To stratify seeds, all you need are some wildflower seeds, a permanent marker, a Ziploc bag and a damp paper towel.
Spread out the damp towel on a flat surface, sprinkle wildflower seeds across it in a single layer and then fold the paper towel over itself. Slip the paper towel into the Ziploc bag and label it with the seed name and date. Pop the Ziploc bag into the refrigerator for about four weeks.
Once the seeds have stratified in the fridge for a month, they can be planted in pots or seed starting trays indoors. Or, temperature permitting, seeds can be planted directly outside in the garden.
Seed packets will generally let you know if their contents should be cold stratified or “chilled” before planting. Plants that are native to warm regions may not need this treatment, but many common native plants of Maine benefit from stratification, including ironweed, black-eyed Susan, coneflower, milkweed and New England asters. Cold stratification can also boost germination rates of certain herbs that are hard to grow from seed, such as lavender.
Lauren Landers of Sullivan is a full-time writer and editor who explores topics in gardening, homesteading and the outdoors. She is a Master Gardener and runs her own website Zero Waste Homestead.
