Wild About Texas – October, 2007

September through November is the ideal time to plant native wildflowers and sow seeds. Most species will germinate from seed when cooler – and typically wetter – weather returns and will grow throughout the winter in preparation for the spectacular spring flowering season. Container-grown plants put into the ground during fall and winter will continue to develop their root systems even if their aerial parts die back from frosts.

Select Appropriate Species

Begin by conducting an inventory of your site, and consider the following:

Light conditions: More sun is best for most species, although there are woodland wildflower species that thrive in shade.

Moisture levels: Identify any low spots that hold water or require less watering, if any. These are ideal places for plants that are adapted to poor drainage. Areas on top of slopes or on thin soils may require more drought resistant species.

Soil type: Heavy clay, fast-draining sand, or thin soils on top of solid limestone will inform your plant selection.

Along with a selection of annuals, perennials and biennials, grasses are important in a meadow as well. Grasses provide a matrix in which the roots of other species grow, reduce erosion, provide food and cover for wildlife and are attractive in their own right. True meadows are composed of approximately 50 to 80 percent grass species, but can be thinned periodically to open up space for showier species.

Avoid seed mixes that include non-native wildflower species such as ox-eye daisy and chicory. Some of these escape cultivation and become noxious agricultural pests and out-compete native species for habitat.

Creating your own seed mix, while it requires more time and thought, allows you to select species that are best suited to your site and give you flexibility to opt for types that bloom at different times of the year.

Container-grown Plants

Since perennial species may not bloom the first spring if planted from seed, many gardeners prefer to incorporate container-grown perennials into their wildflower garden.

Select plants from your local nursery or garden center that have good foliage color and are not root-bound. If cold weather is impending, be sure your plants are properly acclimated before planting them outside, and avoid planting just before severe weather. If your purchases from the nursery have been grown under protected conditions, you can “harden-off” the plants yourself by exposing them to increasingly colder weather until they have become tough or dormant, depending on the species. Tender plants that have not been hardened-off are far less likely to survive a frost.

You don’t have to worry about cold-hardiness when planting species that are native to your region. They are adapted to local conditions. However, plants that are being used at the northernmost edge of their range or in a particularly exposed area may need additional protection during cold spells.

Planting From Seed

Adding container-grown plants to a large area can become costly, and many wildflower species do better when planted from seed. Plant seeds after planting container-grown plants to avoid disturbing newly sprouted seedlings. Directly seeding an area is easy, fast and inexpensive.

Proper site preparation is vital. Begin by thoroughly removing all undesirable vegetation. Persistent, deep-rooted plants and weeds such as bermudagrass and johnsongrass are the biggest challenges and, unfortunately, may require herbicide applications.

It is generally unnecessary to amend your soil with compost or anything else unless you have very thin or imported soils. In fact, many wildflowers perform poorly in rich garden beds. Imported soils will need further analyses to determine necessary changes. If you have very thin soils, you may rely on species that compete well under these conditions (blackfoot daisy, mountain pinks and Texas grama, for example), or you may decide to bring in soil. Avoid soils that may contain noxious weeds. Nutsedge and bermudagrass are two of the worst culprits.

For most garden-sized plots, hand-broadcasting is the simplest method. Adjustable, hand-held spreaders are useful for covering areas that are larger than a few square feet and less than half an acre. For larger areas, a tractor with a harrow attachment may be better suited. To achieve even coverage, combine your seed mix with slightly damp sand or well-sifted soil or compost. Remember to follow seeding rates according to label recommendations and adjust the spreader accordingly.

For seeds to germinate, they must come into direct contact with the soil. Rake the area to lightly work the seed into the soil, but don’t bury the seed more than half an inch. Water the area thoroughly after seeding and periodically thereafter if rainfall is insufficient. Every few weeks, scope the area for encroaching weeds and remove them before they out-compete desirable species or contaminate the area with weed seeds.

Read the next edition of “Wild About Texas” to learn how to learn about long-term management of your wildflower meadow. For more information about how to grow particular species, select the “Explore Plants” tab of the Wildflower Center’s Web site, www.wildflower.org, and visit the Clearinghouse and Native Plant Information sections.

You will find container-grown plants and seeds for more than 300 species of native plants at the Wildflower Center’s Fall Plant Sale and Gardening Festival, Oct. 8-9, 9 a.m.-5p.m. (Members Only Preview sale, Friday, Oct. 7, 1-7p.m. Please bring a wagon.). For more information about this sale, visit www.wildflower.org.

About the author: Andrea DeLong-Amaya is Director of Gardens and Growing at Lady Bird Johnson Wildflower Center in Austin.

Photos by: Joseph Marcus, Lady Bird Johnson Wildflower Center