What's bugging you? Jan. 18, 2017

By Jim Leser


What's bugging you? Jan. 18, 2017 | What's Bugging You, Jim Leser,

Plant

Field bindweed. A pretty flower or a gardener's nightmare? My guess is that you would align with the latter view rather than the former. While there are morning glory species that you could treasure for their blooms, this one should be on your noxious weed list!

This invader from Europe or Asia goes by the Latin name, Convolvulus arvensis, and is a member of the morning glory family. It probably came over here as a crop seed contaminant as early as 1739. Bindweed can be found throughout the United States but is less common to nonexistent in many areas of the southeast. Maybe the weed kudzu crowded it out?

The weed is a perennial that can grow from seed or from rhizomes arising from its extensive root system. Plants generally have a prostrate growth pattern but can climb up objects and plants. Roots can penetrate the soil up to 20 feet deep and grow laterally as much as 10 feet in one growing season. Most roots are found in the upper two feet of soil (70 percent). True leaves are arrow-shaped but the seed leaves (cotyledons) are more square-shaped.

Flowers are trumpet-shaped with colors ranging from white to pink. Each flower produces a capsule fruit containing one to four seeds. A single bindweed plant can produce up to 500 seeds per season and these seeds can remain viable for up to 50 years.

Because of their extensive root system and drought tolerance, bindweed is very difficult to control. Infestations are often found in cultivated areas, wastelands, roadsides and otherwise disturbed areas. Some level of suppression can be had through frequent tillage practices and mulching. But you will never get totally rid of this weed this way, even after several seasons of using barriers or hand tillage practices. If seedlings are removed within three weeks of their emergence, they will fail to establish as a perennial. Likewise, if flowers are removed before seed is produced, the seed bank in your soil can be greatly diminished.

Chemical control in lawns would involve the use of 2,4-D herbicide or maybe even trimec or quadmec. Usually bindweed is not much of a problem in lawns because of frequent mowing. Control in ornamental areas can involve careful use of 2,4-D, glysophate or a combination of the two. Multiple applications over more than one season will be required. Use of a pre-emerge herbicide such as Casoron or trifluralin (PreenĀ® or TreflanĀ®) can be effective in controlling seed germination and even slow down the development of new growth in the spring. Always read the label for any use restrictions, especially when using products around vegetable gardens.

Lastly, there are two arthropods available for sale from the Colorado Department of Agriculture Insectary in Palisade that can provide significant suppression but not eradication. These include a tiny mite and a moth. Give the insectary a call if interested.

Jim Leser retired to Cedaredge in 2007 after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a Colorado Master Gardener.