What Is a Keystone Plant and Which Ones Are the Most Beneficial in Montana?

Thank you to the internet once again.

I'm a beginning gardener and in the last few weeks, I've learned that autumn is actually the best time to garden because that's what all the gardening influencers and gardening accounts on Instagram are telling me.

They're all saying the same thing. Similar to the cooler temperatures of spring, plants also appreciate the colder temperatures of fall because it makes the plants establish firmer roots. So the best time for gardening is right now and in the coming weeks.

Caras Nursery had some great advice about planting in the fall, adding that it's not just the cooler temperatures that make it easier, but there are fewer bugs and diseases in general.

I knew bulbs needed to be planted in the fall, but I decided I'd try some wildflower seeds, too. Then, the Instagram algorithm caught up with me and shared something I'd never heard of.

If you want to benefit the landscape in your area, go beyond planting just native plants. Try planting keystone plants. 

What is a Keystone Plant? 

I'd never heard of a keystone plant before, but the video where I learned about it said it's not that native plants aren't worth it, it's just that keystone plants can support more species than native plants.

But how do you know which plants are keystone plants? You need to know your ecoregion.

What is an Ecoregion? 

This was new to me, too, but it made a lot of sense. Instead of relying on a growing zone, eco regions represent the type of climate where you live. Looking at a map of the Continental United States, Montana has seven ecoregions: Northern Rockies, Idaho Batholith, Middle Rockies, Wyoming Basin, Canadian Rockies, Northwestern Glaciated Plains, and Northwestern Great Plains.

Within these regions, there are even smaller designations you can see on this map.

Which Plants are Keystone Plants in Montana?

Using broader ecoregions from the National Wildlife Federation and the Commission for Environmental Cooperation, Montana falls into the Northwestern Forested Mountains and the Great Plains. According to their data, Oak and sunflower were the most beneficial keystone plants.

In the Northwestern Forested Mountains, 445 caterpillar species use oak as a host plant while 253 species do in the Great Plains. For sunflowers, 22 bee species are supported in the Northwestern Forested Mountains while 89 bee species are supported in the Great Plains.

If you're curious about the trees, shrubs, and flowering perennials for your ecoregion of Montana, click on the links above.