General: Wildflower gardens are very appealing. Since wildflowers are often grown on roadsides, it is logical to think that buying a bunch of seed and sowing it into the desired garden spot is all that is needed. This is where you would be wrong.
Preparation for a wildflower garden must include selecting the proper site, tilling the soil, controlling weeds and finally purchasing the seeds of the plants you have selected. To guide you through this process, there are some excellent references listed on the information page of this website.
Garden Site: Almost all of the plants used in wildflower mixes need full sun; at least 6 hours of sun per day. An available water source is desirable. Although most of the flowers have some drought tolerance, they will need to be irrigated, especially during germination and afterward depending on the weather. Many wildflower are natives and will grow in most any soil type or fertility—some even thrive in nutrient poor soils. If a soil plot will grow weeds, it will support wildflowers.
When to Plant: Wildflower seed purchases are either annuals or perennials or most likely a mix of both. When you plant depends on the type of seed and the expected weather in your area.
In our area, the best time to plant a mixture of annuals and perennials is in spring after the last expected frost. Perennial seed may be planted spring, summer or fall. If planted in fall, there should be at least 10 weeks of growing time before the first hard freeze.
In the wild, annuals reproduce by seeds dropped to the ground in the fall. Similarly, fall planting of annuals and perennials may be done if sown after the first hard freeze. This prevents germination until the next spring and seeds will then have a head start if the birds don't get them.
Seed Selection: There are some good wildflower seed companies from which to obtain seeds. They will have mixes of seeds based on region and also on sun and shade. Two excellent choices are the Vermont Wildflower Farm and Wildseed Farms in Texas. Both of these sites have excellent information about how to start and care for a wildflower garden.
Soil Preparation and Seeding: This step is key in enjoying success and it mainly involves weed control. If you have no reservations about using a herbicide, glyphosate, found in Roundup and many others, is effective. It is inactivated by soil contact and leaves no residual.
Spray the garden bed with glyphosate. Then using a spade or tiller, loosen up the top 1-2 inches of soil; if you go deeper you may bring up dormant weed seeds. Some weeds will recover from the spray and tilling, so after 2-3 weeks, spray the new weeds again. Rake out the dead weeds, but do not till further.
Seeds may be sown 2-3 days after the last glyphosate spraying. They should be sowed while the ground is still loose and will be more evenly spread if the tiny wildflower seeds are mixed with sand.
Sow seeds in two steps, one North-South, and then East-West. After sowing, seeds need to be compressed into the soil. Do not till them in, some will not survive being covered with soil. Either use a lawn roller or place a large board over the seeds and walk on it to squash them into the garden bed.
After planting, irrigate as often as needed to keep the soil constantly moist. Do this until seedlings are 6-8 inches tall. Afterward, water only when the soil is dry.
Maintenance: Most wildflowers need little, if any, fertilizer. Remember, they are wild and tough and get no fertilizer when in their native habitat. If you fertilize, you are assured of getting a huge crop of weeds.
In smaller gardens, hand pulling of weeds before they form seed pods is effective for weed control (the problem is determining what is weed and what is flower). For an invasion of Bermuda grass, there are selective herbicides containing the chemical fluazafop which kill Bermuda grass, but are safe for flowers.
In the late fall, after the first freeze; mow the garden with the mower set high. This will help disperse seeds and help dispose of tall growth. If spots are filled with weeds or if they are bare, simply go through the steps above to reseed.
That’s it. The birds, bees, butterflies and you, are now ready to enjoy the flowers in your garden.