Establishing grasses and wildflowers with plants

For the best results, the soil should be completely free of grass and weeds before planting. The best way to do this is by killing the existing vegetation either organically or with a non-selective herbicide such as glyphosate. At least two herbicide applications are usually required to eliminate existing vegetation. If weeds germinate after the “last” application, spray again on a warm sunny day 10 days prior to planting.

Landscaping Soil Prep

We generally recommend that you do not amend the soil when planting prairie natives. Rich soil encourages these plants to grow too tall and fall over. Lean soil, though harder to plant in, produces better results. Spacing varies by species but 1.5′ centers is a good average for narrow species such as Silky Aster (Aster sericeus), Wild Quinine (Parthenium integrifolium) and Little Bluestem (Schizachyrium scoparium), 2 – 2.5′ centers for wider species such as Purple Coneflower (Echinacea purpurea) and Prairie Dropseed (Sporobolus heterolepis) and 3′ centers for large grasses and creeping plants such as Eastern Gama Grass (Tripsacum dactyloides) and Purple Poppy Mallow (Callirhoe involucrata).

Plants can go in the ground any time from early May until late September. It is generally best to water the planting after it is installed and apply a pre-emergent herbicide. We have successfully used Snapshot and Pendulum for pre-emergent weed control. Mulching just after planting will help conserve moisture and keep weeds at bay the first year. You may have to water several times the first year or two after planting to get plants established. To establish durable, deep root systems water slowly and deeply rather than frequently and shallowly.

A soaker hose is an easy and efficient watering method. Water drips slowly onto the soil right around plant roots for several hours. All of the water soaks directly into the soil and down to plant roots without any waste. The soil around plant roots should be moist, but not soaking wet, the first two weeks. For the next two weeks or so, water when the soil 2 inches below the surface is dry to the touch. After that, check the garden soil periodically and water if the soil 4 inches deep is dry.

Your planting will fill in during the second and third year and will not need additional mulch or water from the third year on.

Establishing grasses and wildflowers with SEED

For the best results, the soil should be completely free of grass and weeds before planting seed. The best way to do this is by killing the existing vegetation either organically or with a non-selective herbicide such as glyphosate. At least two herbicide applications are usually required (one in spring and one in late summer) to eliminate existing vegetation. If weeds germinate after the “last” application, spray again in late October or early November on a warm sunny day.

If a layer of thatch (dead vegetation) covers most of the soil, burn or mow and rake the area so your seed will come in contact with the soil when you put it down. Sow the seeds on the surface evenly in late November through mid-January and let freezing and thawing take them down into the soil. Many of the seeds will germinate during March and April but the warm season grasses won’t germinate until May or June when the soil temperature reaches 60 degrees F.

If you are fall seeding on an erosion prone site, plant a nurse crop of annual rye or oats by mid September to stabilize the soil. The nurse crop will be killed by cold temperature but the dead roots will hold the soil in place through winter and will still allow the native seed to germinate in spring.

Seed can be sown in a number of ways, depending on the size of your area. Hand broadcasting works well in areas of one to two acres. If you select this method, mix the seed evenly with one bushel of inert material for every 1,000 square feet of planting area. Slightly damp sawdust, peat, vermiculite, potash, ground corn or other inert material makes it much easier to evenly distribute the seed. Take one-half of the total mix and distribute it evenly over the entire area. Then, take the remaining half and spread it over the same area, walking perpendicular to your first pass. Roll the site with a roller or drive across it with a car or truck to firm the seed into the soil. Do not roll the site if the soil is wet.

Landscaping: What to Expect

When planting areas over two acres in size, use a broadcast seeder mounted to an ATV or tractor. Mix the seed with inert material as previously described. Talk with your Private Land Conservationist about the type of planting method best suited to your needs. They can also help locate suppliers that rent equipment or contractors familiar with seeding native plants.

What to expect

Container-grown native plants put in gardens with no weed competition and adequate water usually put on astounding growth the first year and will be fully mature by the third year. Most native trees, shrubs and vines planted from containers also establish quickly. However, native plants from seed take longer to get going. Wildflowers and grasses planted from seed spend the first year, and sometimes three years, sinking their extensive root systems into the soil. For this reason, you might not see a lot of top growth right away. Be patient. These large root systems are what sustain the plants through drought and harsh winters.