URBANA, Ill. — As populations of bees and butterflies decline in the Midwest, native prairie restoration becomes crucial. A new Prairie Research Institute study found, however, that many commercial seed mixes used to conserve and restore prairies may not have enough diversity or spring flowering plants to fully support these pollinators.

“Imagine being an insect and waking up in the spring. You’re metabolically stressed and you go to a habitat made just for you, but there’s no food available for two months,” said Jack Zinnen, a PRI wetland plant ecologist and lead author on the study. “That’s why a lack of plant diversity is a big deal.”

The study compared 196 seed mixes designed for pollinators against 102 prairie remnants in eight states, finding that the seed mixes offered less blooming richness and fewer early-blooming species.

“The irony is that you have these seed mixes that are explicitly for pollinator conservation, but they will not be supporting pollinators well for the first part of the growing season,” he said.

The paper, published in the journal Restoration Ecology, builds on Zinnen’s previous research that included a survey of 557 plant vendors selling native plants across the Midwest and investigated the contents of commercial seed mixes. The new study compared the diversity of wildflowers in pollinator-specific seed mixes to that of prairie remnants, which are prairies that remain undisturbed by agriculture or development.

Zinnen found that most mixes contained few, if any, plant species that bloom before the second or third week of June. About 28% percent of wildflower species in the remnants studied flower by the end of May, compared with 0-13% in seed mixes.

Read the full article from the Prairie Research Institute.