When to Plant
Wildflowers take more moisture to germinate than grasses. Once planted, seeds must remain moist to ensure a successful stand. Some seeds will germinate and bloom the first year, while others will not begin blooming until the second year.
Certain wildflower species need to germinate as seedlings in the fall and over winter to develop hardy root systems by spring. Seeds of other species need winter temperatures and rains to break their dormancy; therefore, the best planting times will vary from region to region. The optimum rainfall period, severity of winter and the dormancy of seed will determine the most favorable time to plant wildflowers in your area.
When planting in the spring, plant early when ample rainfall is anticipated. Seeds may be planted all summer if they can be watered. We recommend that wildflowers be planted at the same time as the prairie grasses. Planting wildflowers into established prairie grass has produced disappointing results.
Most varieties prefer full sun with exposure to drying winds. Select a site that receives full to partial sun and is well drained.
Preparing the Bed
The main objective when preparing the seedbed is to provide optimum seed-to-soil contact and eliminate any undesirable plants or grasses. This can be accomplished two ways: chemical or tillage treatment.
Several commercial herbicides are available that will eliminate the aggressive cool season sod-forming grasses. Round-up is the most popular. These grasses must be removed before planting a wildflower or prairie grass site. Your local garden center or county extension agent can make recommendations for accurate and timely application.
Repeated tillage is the other option available to control undesired plant growth. In some cases of heavy sod-forming grasses, this may take a season of repeated tilling. Care must be taken to completely eliminate any cool season sod-forming grasses, as they can return to compete mercilessly with your prairie plantings. Prior to planting, the seedbed should be firm and free of clumps.
Dry soils with low organic matter have little nutrient value and make plant growth difficult. Plants with a deep root structure can usually provide the drought and heat tolerance needed to exist in these soils. Some of the flowers that have demonstrated ability to survive in sand soils are: Butterfly Plant, Upright Prairie Cornflower, Purple Prairie Clover, Perennial Lupine, Cornflower, Lemon Mint, Blanketflower, Missouri Primrose, Blue Flax, Black-Eyed Susan, False Sunflower and Partridgepea.
Shade, by definition, is an area that is sheltered from the heat and glare of the sun. As we often speak of partial shade tolerance, we should define this area in regard to a plant’s growth pattern. The majority of wildflowers are the warm season prairie-type and require full sunlight. Woodland-type plants can flourish in shaded areas, but most need a certain amount of direct sunlight. The wildflowers listed below are the prairie type and should provide a satisfactory bloom with a minimum of six hours of sunlight a day. Good soil fertility and occasional watering during dry periods will help tolerate shady conditions.
Wildflowers adaptable to shade areas are: Shasta Daisy, Lance-Leafed Coreopsis, Dames Rocket, Purple Coneflower, Scarlet Flax, Cornflower, Mexican Red Hat, Prairie Aster, Black-Eyed Susan, False Sunflower, Catchfly and New England Aster.
Sowing the Seed
A small amount of wildflower seed goes a long way. When hand broadcasting the seed, it is good to mix the seed with damp sand (4:1 sand to seed) to help prevent clumping and provide even distribution. Rake the seed in lightly, being careful not to bury it too deeply. A good rule of thumb; bury the seed to deeper than two-to-four times as deep as its diameter. Tamp to firm the seedbed after seeding.
Care After Planting
All seeds need water to germinate. Plantings should be kept moist during their early stages of development. Light watering three or four times a week will help ensure optimum germination. During their establishment and blooming stages, supplemental watering once a week (more often if natural rainfall is low) will help wildflowers thrive and may even prolong the blooming periods of some species. It is generally unnecessary to fertilize wildflowers if they are planted in their native habitat. In fact, fertilizing may produce excessive foliage at the expense of blooms.
Weeds still will need to be pulled as soon as they can be identified. Mowing can also control some weeds, but the blade must be clear the height of the desired seedlings. Commercial herbicides are available for grass control in established stands. Consult your local garden store or county extension office.
Wait to clear your wildflower garden until all the species have gone to seed to allow them to re-seed themselves. It may require some patience on your part, since wildflowers tend to look rather unkempt during their final stages.
Patience Is A Virtue
In reconstructing a natural setting, it is important to remember that we cannot do in one year what took nature many lifetimes to create. The first year can be somewhat frustrating because that visual picture you have in your mind does not happen. The long-lasting perennials normally take two and sometimes three years to bloom. While a few varieties bloom the first year, we recommend including annuals to guarantee color during the seeding year.
Patience will be rewarded with the beauty of the many colored wildflowers that will be enjoyed for many years. Even once established , areas planted to wildflowers will vary from year to year as environmental conditions cause some varieties to go dormant while others bloom actively—A testimony to the incredible durability of the native landscape!