Two cool varieties added to
June 30, 2005
Blue cape plumbago
and vitex, or
The Texas Superstar program is an educational and marketing campaign which Texas A&M started in 1989, with input on plant sustainability from Aggie horticulturists, nursery professionals, growers, seed company representatives, county horticulturists, arboretum and botanical garden representatives, horticultural writers and landscape designers.
Decisions to award Superstar status are primarily based upon observations made at replicated plots and demonstration trials across the state or even by recommendations from other Southern states.
Plumbago auriculata, or cape plumbago, produces beautiful, phlox-like clusters of blue
flowers all summer long until frost. The name "plumbago,"
or leadwort, comes from "plumbum," Latin
for lead, because the plant was believed to be a cure for lead poisoning at one
time. While it is native to
The rich, bluer cultivar,
Like all Texas Superstars, this tender, perennial shrub is easily grown in most soil types with good drainage. Reaching heights of 3-4 feet and up to 5-feet wide, it responds well to pruning. In fact, it is a bit rambling if not pruned. There are quite a few planted out at the Master Gardener Victoria Educational Gardens, and they are trimmed frequently to keep them within their bounds and to encourage re-blooming since they bloom on new wood.
Plumbago will freeze back with the first hard freeze, but don't despair or be tempted to dig it out as growth will return in spring. If the temperatures do not get that cold, it is advisable to prune it back to about 1/3 its size. It is helpful to add fertilizer when growth starts in early spring.
Plumbago can be used in informal hedges, but should be planted
with winter annuals or other evergreen plants so you won't have a bare spot
during winter. They are versatile enough to be planted with
The other new
A native of
Vitex grows and blooms best in full sun in soil that drains well. They can grow to 25 feet, but the most common size is 12-15 feet. Vitex are so tough and love heat so much so that they have been planted in the highway medians by the Texas Highway Department and in areas getting only natural water.
I discovered six beautiful chaste trees along the walking trail in Riverside Park below the Victoria Rose Garden and wondered how old they are and how much care they are given, if any. They must be the new and improved variety, because the flower spikes are about 8 inches long. The old vitex, that people have seen around for years, have small spikes of flowers that were pale lilac, mauve, off-white or light pink and were not very desirable.
Horticulturists now have identified and
tested improved varieties such as Montrose Purple, LeCompte
and Shoal Creek, with 8- to 12-inch flower spikes. These varieties are all
marketed under the name
After several weeks of beauty the flower racemes produce fruit with dark seeds resembling pepper, which could produce a mutant seedling population with less desirable blooms. This can be avoided by deadheading, which can be challenging, since vitex is extremely fast growing. They will in turn bloom again within a month.
Jerry Parsons, a professor at
http://aggie-horticulture.tamu.edu/cemap/plumbago/plumbago.html More information can be found at these sites also:
Parsons encourages keeping vitex a small shrub size and not letting them get any
taller than 6 feet so that the spent flowers can be reached for pruning.
Fertilizing after pruning will encourage new growth and re-blooming. The
flowers will form on the new wood, such as with the plumbago,
perennial hibiscus, esperanza
and hamelia or firebush. In
cooler areas of
We should all encourage pollinators, such as bees, butterflies, and hummingbirds to visit our gardens and landscapes, and it's always great to sit out and watch and listen to other birds that are attracted to dense bushy growth. So why not plant vitex and plumbago, two of the best "blues" and keep the "blues" away?