Marestail, also known as horseweed and Canada fleabane, has developed resistance to
glyphosate, the active ingredient in RoundUp. Although it is native throughout
North America, marestail has become quite weedy due to its ability to produce
and spread large quantities of seed. An individual plant can produce up to
200,000 seeds! And the seeds have a bristly-hairy appendage that facilitates
being distributed by wind.
In the northern parts of Indiana, marestail is typically a winter annual
(seed germinates in the fall, overwinters as a leafy rosette, then flowers and
sets seeds in spring.) In southern areas of Indiana, it is more typically a
summer annual (spring germination with summer flowering and seed.) The
plants can reach up to 6 feet tall.
The herbicides that provide good control of marestail are not generally
available or practical for home gardens and landscapes. In the yard and garden,
the most successful control strategy is preventing the plants from going to
seed. Mowing, hoeing and digging the plants before they flower is key. Small,
young plants will be easier to control. Mulching might help suppress
germination of existing seeds.
Although aimed at agronomic production, Purdue Extension publication ID-323,
Biology and Management of Horseweed, has additional information of interest to home gardeners.
By B. Rosie Lerner
Purdue Extension
Consumer Horticulturist |
No comments:
Post a Comment