Growing wildflowers can be an enjoyable experience with proper planning and implementation of these small projects. Wildflowers generally are not susceptible to insects and diseases and typically require only routine care such as watering, maintaining ample fertility and controlling undesirable weeds. Each species may have specific growing requirements, but variable conditions may affect how it performs. By following our step-by-step small project guidelines, hopefully success will be achieved. If your site is less than favorable, you may wish to consult with local colleges, universities, extension agents or other plant specialists.
Site selection should be the first consideration in planning your wildflower garden, even with a small project. It is important to select seed/plants that will adapt successfully to the soil type (sand, loam, clay, etc.) on your site. If you have poor soil, you can improve it by adding organic matter such as manure or compost from yard waste or other materials. Plants such as Black-eyed Susan, Lance-leaved Coreopsis, and Narrow-leaved Sunflower will grow in poorly drained soils, whereas annuals such as Poppies and Cosmos need a loose well-drained soil to establish and thrive.
When to Plant
With adequate soil temperatures, moisture and sunlight, wildflower seeds will germinate. Most species need a soil temperature between 55° F to 75° F is ideal. Spring seeding is recommended for northern or northeastern regions of the United States due to the harsh winter conditions. Fall, winter or spring seeding is recommended for southern and southeastern regions with the fall period generally recognized as the optimum seeding period. Plants that are susceptible to frost/freeze damage (i.e., cosmos) should be planted in the spring and summer only. More recently, our on-farm research has shown that July to August is a great time to plant perennial wildflowers such as Lance-leaved Coreopsis, Black-eyed Susan and Coreopsis Grandiflora.
Your site may need to be sprayed with Roundup™ or a similar product to eliminate existing undesirable broadleaf weeds or grasses. Allow sufficient time for weeds to decline before mowing or tilling. Respraying may be necessary to eliminate hard to control perennial weeds. The site should then be mowed to shred existing vegetative cover.
Soil samples should be taken to determine soil pH and fertility requirements. Based on soil test results, add amendments such as lime, fertilizer, compost and other components as needed. If soil test data is not available, and the soil is nutrient depleted, use a mixed fertilizer such as 8-8-8 or 10-10-10 at a typical garden application rate. Composted products such as poultry litter, horse manure and municipal sludge are excellent sources of nutrient based organic matter that can improve wildflower seedling performance and ultimately flower quality. Do not mix noncomposted organic matter such as leaves, wood chips, and fresh saw dust or shavings due to potential for plant nutrient deficiencies while the raw material is decaying.
Mix soil additives including lime, fertilizer, and/or compost with a rototiller, disk, or other tillage equipment capable of thoroughly mixing and pulverizing to a depth of one to three inches. Soils that have been properly tilled and contain loose soil will produce higher plant populations and improve plant growth. The tillage method used should leave soil surface smooth and free of heavy vegetative cover and debris.
Seed can be sown with conventional seed/fertilizer broadcast applicators. Wildflower seeds are very small in size (i.e. Corn Poppy, Ox-eye Daisy) and should be mixed with sand, fertilizer, vermiculite or other carrier to facilitate even distribution. A seed application pattern similar to that used to seed home lawns is sufficient. The recommended seeding rates should be followed to create healthy plant populations and discourage weed growth.
Seed should be lightly covered with soil by hand raking, rolling, or shallow harrowing to accomplish good seed to soil contact. CAUTION – wildflower seed should be planted very shallow, 1/16″ for most species. Always be patient and maintain adequate moisture to encourage healthy plant growth.