Ask a Master Gardener: Prairie Garden Planning

It must be garden planning season because two different people recently asked me variations of this question. Let’s dig in.

Question:

I’d really like to convert part of my yard into a prairie garden. Can I just stop mowing it and let it naturally convert back to prairie? If I want to add plants, which plants do you recommend?

Answer:

This is a great question, and it requires a multi-part answer. Pour yourself a cup of coffee or tea because this is a long one.

First, and critically, I’m sorry to say that, unless your lawn is surrounded on all sides by restored or original prairie, the only thing that will thrive if you “let it go” is noxious weeds. “No Mow May” is really popular, and I support it, but only as a gateway to questioning why we dedicate so much space to lawn in the first place. Dandelions are better for bees than nothing, but only barely. Unless you take absolutely pristine care of your lawn, you likely have some weedy grasses like crabgrass, Bermuda grass and barnyard grass. And then there are flowering weeds.

If you really want an actual mini prairie that looks intentional and supports wildlife that evolved with it, you’re going to have to do a little work.

The cheapest and easiest way to convert part of your yard to prairie (with a seed mix) also happens to take the most time. Assuming you start in 2024, here’s a sample timeline:

TIMELINE: INEXPENSIVE, BUT LONGER-TERM

Right NOW! 

Determine what type of area you have and what kind of prairie you want. Does your soil tend to be dry? Is the area you want to plant above a septic tank? Would you rather have tall plants, short ones or a mix? The possibilities are endless.

I recommend purchasing a seed mix from a dedicated native plant nursery, such as Prairie Moon Nursery. Restoring prairies is part of their mission, and they select only native species that evolved here. They offer a wide variety of seed mixes, from Tall Sedge Meadow to Deer Resistant to Pretty Darn Quick.

Other midwestern sources for prairie seeds include Prairie Nursery, Prairie Restorations and Minnesota Native Landscapes. 

Please note: do NOT buy wildflower mixes from big box stores. They contain many annuals, few quality perennials and some even have noxious weed seeds in them. Here’s an example of the ingredient list of Burpee’s “Monarch Magnet” wildflower seed mix: 10% cornflower, 10% crimson clover, 10% Siberian wallflower, 8% baby’s breath, 8% perennial lupine, 6% Indian blanket, 5% or less of butterflyweed, coreopsis, cosmos, larkspur, purple coneflower, sunflower, gayfeather, sweet alyssum, bergamot, black-eyed susan, marigold, Mexican sunflower and zinnia

When I saw this mix for sale at a big box store last summer, I was shocked. It contains almost no native plants (the plants that monarch butterflies and other pollinators evolved with and need to thrive). Sure, a monarch butterfly might occasionally sip nectar from a zinnia or a cornflower, but this mix is *not* going to create anything resembling a restored prairie in your yard, and some of these plants are invasive. I’m looking at you, lupine.

My suggestion? Check out local native plant nurseries, decide on what seed mix you want and proceed from there.

Spring or Summer 2024

The first step? Kill everything that’s growing in the area you want to convert to prairie. There are a number of ways to achieve this, including 2-3 applications of glyphosate over the course of the growing season, or solarization. No matter what way you choose, plan on it taking several weeks at a minimum.

Fall 2024

Scatter your preferred prairie restoration seed mix in the area and mulch lightly with straw. If you purchase a seed mix from a reputable native plant nursery, it will come with instructions.  

2025 Growing Season

Mow periodically to a height of 4-6” to allow the new plants to get established while minimizing weeds and making sure no weeds can flower and go to seed. Note: hand-pulling weeds is actually not recommended. Just keep them mowed.

2026 Growing Season and Beyond

Now the magic happens. You’ve been waiting for it! And it’s time. Your restored prairie will change a bit from year to year, and that’s part of the magic. For long-term management, you could choose to do occasional controlled burns or simply mow it once a year in spring. Some of the grass stalk debris may need to be removed occasionally if it gets so thick that it’s smothering the plants below it.

Seriously, three years? Yep. If I ever create a prairie garden larger than 10 x 10 feet, this is how I’d do it.

Want a pocket prairie and/or need it RIGHT NOW? If you have a decent-sized budget and/or a very small area, you can still have a prairie this year, in 2024.

TIMELINE: MORE EXPENSIVE, BUT FAST

Step 1, Now:

Do the research. Use the same websites listed above. Many of them sell plants in addition to seeds. Local native plant nurseries also sell these plants in the spring, and look for special plant sales. Wild Ones provides information on numerous native plant sale opportunities in the spring.

Step 2, Spring 2024:

Rent a sod cutter and clear the area. Plant your new seedlings and mulch with straw. Plan on one plant per square foot of your new garden—this will help shade the ground and prevent some weeds from sprouting and help it fill in faster. Your eventual goal with a prairie planting is continuous plants and no visible mulch at all. You want a filled-in meadow look.

For more information on designing a prairie garden with plants, check out the new book Prairie Up by my fellow Northern Gardener® magazine contributor Benjamin Vogt.

When your plants are in the ground, you have the beginnings of a prairie! Draw a map of what you planted where, or use the plant tags. Keep it weeded! Even if you cut the sod off, you will still have weeds. Either trim them to the ground with scissors or pull them. Keep it watered, deeply, once per week if we have a drought year, until the plants are well-established.

Allow your prairie plants to live their full life-cycle, flower and go to seed. Resist the urge to cut them back in the fall. They will spread and fill in eventually, but it may take a few years. They will also move around a bit, especially milkweeds. Commit to learning how to identify at least some of your key plants as seedlings, so that you don’t accidentally pull something you want. 

When I was a new native plant gardener, I frequently did Google Images searches for things like “purple coneflower seedling” or “baby milkweed plant” to help me determine whether a plant that popped up unexpectedly was something I wanted or not.

Depending on the composition of your prairie, you may still want to employ mowing or burning as a long-term strategy (starting in 2026).

VARIATION: LESS WORK, BUT PRETTY FAST

If the thought of sod cutters makes you groan, you could sheet mulch the area with plain uncoated cardboard and 2-3 inches of woodchip mulch. This smothers weeds effectively but must be done several weeks before you plant, so you can wait for the cardboard to at least start breaking down. Ideally, you’d do it as soon as the snow is gone in April in order to plant by the end of May or early June. If the weather is dry, water the whole thing occasionally to help the process move along. Gently pull apart the woodchips, cut small holes in the cardboard if it’s still there and plant seedlings right into the ground.

RESOURCES

Most of this information is from the University of Minnesota Extension’s thorough yet easy-to-digest guide to planting prairies.

Want more? The Nature Conservancy has an exhaustive guide to prairie restoration.

Several local native plant nurseries—notably Prairie Restorations—also provide prairie installation and maintenance services, if this feels overwhelming as a DIY.

A selection of local native plant nurseries:

• Minnesota and Western Wisconsin Native Plant Nursery and Landscape Services Listing (WOMN) 
• Blazing Star Gardens, Owatonna, MN (retail nursery)
• Ecoscapes Sustainable Landscaping, Burnsville, MN   
• Landscape Alternatives, Inc., Shafer, MN (retail nursery)
• Minnesota Native Landscapes (MNL), Otsego, MN
• Natural Shore Technologies, Independence, MN (retail nursery)
• Out Back Nursery, Hastings, MN (retail nursery)
• Prairie Moon Nursery , Winona, MN
• Prairie Restorations, Inc (PRI), Princeton, MN (retail nursery and store)

Have you created a prairie garden? Share your tricks and tips below!

Have gardening questions? You can Ask a Master Gardener online or call the Yard & Garden Line at (612) 301-7590.

Other helpful resources:

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Jennifer Rensenbrink is a University of Minnesota Extension Master Gardener Volunteer for Hennepin County. She somehow has two mini-prairies on her tiny south Minneapolis property—follow along on her gardening adventures on Instagram at @jenniferrensenbrink.