Weekly Express-News Article
By Calvin R. Finch, PhD, SAWS Water Resources Director, and Horticulturist
Saturday, September 15, 2007
Most of our wildflowers bloom in the spring, but now is the time
to plant their seed. Wildflowers do not require much work, but
if they are going to germinate and bloom, certain conditions for
a site are required.
• Wildflower seed must reach the soil and not be covered
by organic material. That means the best sites have sparse weed
cover, and definitely, are not covered by sod.
• Most wildflowers require full sun. They will not bloom
in a shady situation.
• Wildflowers will grow in good soil, but do not require
it. A rocky thin soil is often the best wildflower planting choice
because it is well drained and most other plants do not prosper
in such a setting. If the vacant lot or field you are considering
dries out every autumn to the extent that you can see bare soil,
it is probably a good wildflower plot.
• You can reduce weed cover prior to planting the seed
by mowing very low or discing, but if that treatment is necessary
it does not bode well for natural reseeding. The thick weeds will
probably be back the next year and the seed dropped by your planted
wildflowers will not find the soil contact and light penetration
conditions that are required.
Wildflowers can actually be planted in rows in plowed and enriched
soils, but that really doesn’t make much sense to me. Wildflowers
are interesting, tough, and can make an impact when they bloom
in masses over a large area, but their blooms are not as showy
as domesticated flowers. If you are going to prepare the soil
to the degree required by snapdragons and stocks, you may as well
grow snapdragons and stocks.
If you select the right site, all it takes is spreading the seed
by hand broadcast. A pre and/or post shallow raking increases
the germination success, but is not necessary. The seed should
not be covered with soil.
The spring blooming wildflowers germinate in the autumn and develop
root systems all winter so they can grow quickly and bloom in
the spring. Irrigation is not necessary, but the amount of rain
helps determine the timing and volume of bloom. A good soaking
rain or two, right after the seed is spread and then a good rain
in February is usually all that is required. In fact, too much
rain can be a problem and result in fewer plants and competing
There are a number of ways to obtain your wildflower seeds. Many
area nurseries sell packets of Texas wildflower mix which includes
verbena, bluebonnet, coreopsis, poppies, firewheel, Mexican hat,
larkspur, purple coneflower, and other species.
You can also purchase wildflower seeds on the internet. There
are several Texas growers that are very reliable.
Bluebonnets are the Texas state flower and by far the most popular
wildflower. They bloom in several shades of blue and white, pink,
maroon, and “almost red.” Bluebonnets begin blooming
in mid-March and often bloom through April. The seeds you buy
retail are usually scarified with acid to increase germination.
Coreopsis is also called tickseed. The blooms are yellow, silver
dollar size, and daisy-like. They are more tolerant of wet springs
than bluebonnets. Most years, they bloom after bluebonnets. On
sites they favor they will cover the ground 12 inches deep with
a carpet of bloom. Butterflies are especially fond of coreopsis.
Firewheel also has a daisy-like bloom, but the flower has a rust-red
on the petals in addition to a yellow ring. Firewheel and Mexican
hat, another daisy-like rust colored bloom are the wildflowers
that seem to be the most tolerant of dry conditions in mixed seed
packets. They bloom after coreopsis and bluebonnets.
Prairie verbena has a blue lavender bloom that is very attractive
to butterflies. This flower often begins to bloom earliest of
the wildflowers and lingers after the others have quit blooming.
It does not usually dominate a field, like bluebonnet, coreopsis
or firewheel may.
Larkspurs are not a native wildflower, but they naturalize well
in more fertile situations. The plants reach 18 inches tall on
most sites and bloom in blue, purple, pink, and white. Larkspurs
are a favorite hummingbird nectar source.
Purple coneflower is a perennial wildflower. It is included
in every wildflower mix. The flowers are large with a brown center
and lavender petals. They bloom in late spring then often again
Salvia coccinea is usually the only wildflower included in the
Texas mix that blooms in sun or shade. The plant has red tubular
flowers on stalks that reach 18 inches tall. It is the latest
bloomer in the mix, starting in mid-summer and blooming through
late fall. Hummingbirds like Salvia coccinea.