Wildflower seeds and mixtures from wildflowersonline.com.

Providing good drainage. Good drainage is essential for the best plant growth. If water doesn't soak in, runs off quickly or keeps the soil continually soggy, you may need to till the soil and add amendments to improve drainage. On slopes, use low-volume irrigation such as mini- or micro-sprinklers to minimize surface runoff and erosion of the seed and soil.

Controlling weeds. Weeds are a great threat to the success of your wildflowers. Weeds generally grow taller and faster than wildflowers, robbing the soil of moisture and nutrients and eventually sunlight. Therefore, it is important to remove weeds before seeding. Clear the area of existing weeds with a fast-acting, non-selective systemic herbicide, such as Monsanto's Roundup. If tilling is necessary to improve soil structure, it should be done after weed control. If tilling is not necessary, move on to watering.

Tilling. It is best not to heavily till the area as it may bring dormant weed seeds to the surface where they will germinate and compete with the wildflowers. However, if there is soil compaction or poor drainage, you should till. When tilling, incorporate organic material, such as humus mulch or compost, and then grade the soil into a firm seed bed.

For large areas, it might be necessary to use a flail mower or tractor to rough up the soil surface and remove existing vegetation. It is important to remove enough vegetation to ensure that the seed is in firm contact with the soil. If the seed is not in direct contact with the soil, it will germinate and die because the root will be unable to obtain water and nutrients essential for growth.
For small areas, lightly rake to scalp or scarify the soil, loosening as much as two inches of the soil surface.
Practice weed germination and removal as described in "Controlling weeds."

Watering. After weeds have been removed and the soil has been tilled, water the area frequently for two to three weeks to allow weed seeds to germinate. Once the seeds have germinated, apply the non-selective herbicide but do not disturb the soil any further as this could cause new weed growth. Seeding should take place about two weeks after applying the herbicide. Consult the instructions on the herbicide package for specific waiting periods.

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