Express-News
Saturday, October 9, 2004
By Calvin Finch, Conservation Director, SAWS, and Horticulturist

WILDFLOWER SEED TIME

It is time to get your wildflowers planted.  Wildflowers do not need much soil preparation or care after they are planted, but you must do a good job of selecting the site if you want success.

Look for a site where bare ground is visible and the soil receives full sun.  The seed, when you spread it, must make contact with the soil and the sun must reach the seed.  Our favorite wildflowers do not prosper or even germinate in locations that are shady or where there is a sod cover.

A portion of the seed of bluebonnets, coreopsis (tickseed), poppies, verbena, primrose and Mexican hat will germinate if you just spread the seed on the soil.  If you can disc till or even rake the soil surface before the seed is applied it will increase the germination rate.  Do not bury the seed.  Enough will sift into the soil to produce a good germination rate.

Wildflowers are good xeriscape plants; they do not need supplemental irrigation.  The germination rate will be higher if you spread the seed before rain or if you can apply one application of irrigation but it is not essential.

            Wildflowers provide attractive flowers in the spring.  A field of bluebonnets, coreopsis or poppies can be spectacular.  The color, however, is not over a long season.  About the end of April the wildflowers have gone to seed and the result is a weedy field.  If your reaction is “fine,” we can just mow down the weedy field, the flowers will not reseed.  Part of the goal with wildflowers is to get them to naturalize (reseed).  This will only happen if you allow the seed to mature and drop.  Mow too early and the seed will not be viable.  Another strategy that will work some years is to try and have a mix of wildflowers that provide season long blooms.  Purple coneflowers, black-eyed susan and Salvia coccinea do pretty well in the autumn.  The summer gap can be filled by cosmos if you spread seed every April.

For some great information on wildflowers, visit the website plantanswers.com, it will link you with the Wildseed Farms website.  The site provides pictures of the wildflowers, a diagram of what the seedling looks like and how much seed is required to cover 1,000 sq feet of ground.  Most wildflowers require full sun but there are a few that will perform in the shade.  Blue curls (Phacelia congesta) have a blue caterpillar-like flower on a 2-foot tall plant.  It is very attractive in shade under deciduous or evergreen trees.  The seed, however, is hard to find commercially.  You may have to harvest some from a friend’s planting.  Another shade tolerant wildflower is Salvia coccinea.  It has a red flower on a stalk that reaches two to three feet tall.  S. coccinea is also desirable because it blooms in the fall.  Hummingbirds like Salvia coccinea and the seed is easy to find. 

            Larkspur qualifies as a wildflower by the some definitions.  In my landscape a few manage to grow on the rocky baked soils of a vacant lot along with the tickseed, verbenas and bluebonnets, but they do much better as a reseeding annual in my raised bed cutting garden.  Larkspur can be single or double in purple, blue, white and pink.  Most reach three feet tall.  They are favorite butterfly plants and make an excellent show.  Spread the seed now or plant transplants next spring. 

A solid planting of common blue bluebonnets is very attractive.  For something different plant the maroon, white or red versions.  The unusual colored seed can be relatively expensive at around $10 per ounce.  The blue versions cost about $4 per ounce. 

            I have not had good luck with poppies.  They bloom later than the bluebonnets and offer a large variety of striking colors.  At least one of my neighbors has a nice show every spring.  The planting at the Botanical Garden is also inspiring.  Encouraged by their example, I have not given up.  Another two pounds of corn poppy seed went in the fall.  Eventually I expect to be successful.

            The example of my experience with poppies is common with wildflowers.  There are always some varieties that do better on any specific site than on other pieces of land.  The weather is always a factor as well.  Wet years favor some species and dry years favor other species.  One of the best strategies is to try a mix of seeds on a site.  Let the conditions and weather determine which wildflowers end up dominant.

            Wildflower seeds are available at most area nurseries and from internet vendors.  It is time to spread the seed.