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WEED OF THE WEEK - HEATH ASTER
B: Well, if you were not able to identify our weed of the week,
you're not alone. It's not the most common weed, and it is tough
to identify. It's heath aster.
D: While you may not have known what it was this time, we'll go
through the steps to identifying it, so you can recognize it in
your area.
B: We'll also discuss why this weed is so troublesome, and stick
around, because we'll show you how to control it, as well.
D: Heath aster, which is also sometimes called white aster, is
a perennial weed that reproduces by rhizomes, stolons, and seeds.
These factors make it a difficult weed to stop. As we have mentioned
on previous shows, many perennial weeds have root systems containing
rhizomes and stolons. Rhizomes and stolons are just like regular
roots, except their primary function is not to bring in water and
nutrients, rather, it is to extend and start new shoots. Each new
shoot contains a separate growing point. Therefore, if the plant
gets cut off in between these shoots, each shoot can survive. A
rhizome will run below ground, while a stolon runs on top of the
soil surface.
B: As we mentioned earlier, heath aster is difficult to identify,
but here are some tips to help you spot it. The rough and hairy
leaves of the plant run alternately up the stem. These leaves are
long and narrow. Also, as the season progresses, it is very common
for many of the leaves to drop off the plant.
D: The stems on heath aster plants are usually in clusters. These
stems are usually slightly hairy, narrow, and fairly short. Heath
aster plants are typically less than 3 feet tall.
B: When these plants near full maturity, they become easier to
identify. Towards fall, they will put on white ray flowers that
surround yellow or purple disk flowers. Below these flowers, you'll
find the fruit of the heath aster. It's called achene. Each achene
contains one seed, and the achene will be brown or purple with little
bristles.
D: Another way to identify heath aster, is to look at the root
system. Again, on most plants you'll find rhizomes and stolons.
B: Heath aster can show up just about anywhere, but it is most
commonly found in non-crop ground. Animals usually don't like to
eat it, however, so you'll usually find plants intact. One of the
reasons most animals have probably figured out that they don't like
heath aster as a meal, is that the plant can be poisonous if eaten.
Therefore, if you are baling your road ditches or pastures, make
sure that heath aster is controlled, so you don't run into potential
problems with livestock poisoning.
D: Speaking of control, the best products are Tordon, Velpar, and
our old favorite, 2,4-D. As always, 2,4-D is the most inexpensive
herbicide you can use to kill weeds in pastures and road ditches.
However, since heath aster is a tough perennial, you'll probably
need to use at least 2 quarts of LV-4 or 1.33 quarts of LV-6 sprayed
2 to 3 times per year to stop this weed. Tordon and Velpar, although
they are more expensive, can usually provide similar results with
one application per year.
B: We've never spent much time talking about Velpar before, but
it does have a fit in this situation. Velpar is commonly used in
forestry or pasture spraying. Velpar is in the triazine chemical
family, so it is somewhat similar to atrazine and Sencor.
D: Velpar has both contact and residual control. While it can kill
a variety of weeds, it is especially known for its activity on woody
plants and brush.
B: Turning now to crop ground, if you need to control heath aster,
our best suggestion is to use Roundup Ready soybeans if you're planting
beans. In corn, you'll get suppression out of Distinct and Clarity.
Plus, once the corn canopies, it will begin to choke out this weed.
D: In review, heath aster is a perennial weed that reproduces by
seed, rhizomes, and stolons.
B: It is a shorter plant than can be poisonous if eaten.
D: To control it, use Tordon, Velpar, or 2,4-D in non-crop ground
or put Roundup on Roundup Ready crops.
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11/04/01
