Aug. 26, 2010

Here's Randy's Weekly KTRH GardenLine Tip:

Issue #176

Over the past few weekends, starting with an appearance at an Ace Hardware store in The Woodlands, I've been seeing more and more listener samples of doveweed and chamberbitter. So, I thought I'd cover both in this tip sheet, mainly because they can each be treated the same way ... despite the mistaken theory that one's a grassy weed and one is not.

Let's start with doveweed. It may be the "Rodney Daingerfield" of the weed world ... it really gets no respect. Everyone, including me, misidentifies it from time to time. And we often lump it in with basketgrass and, very errantly, Virginia buttonweed. Doveweed is not even remotely related to either, since it's truly a Murdannia nudiflora.

It often gets mislabeled as Virginia buttonweed becuase the two weeds' flowers aren't much different. But, doveweed blades almost look like St. Augustine grass, and that could never be mistaken for Virginia buttonweed. In fact, the shape of the leaves in their earliest stages can often mimic basketgrass. The major difference in the two is that basketgrass spreads on runners or stems, but doveweed regenerates one-by-one, one sprout next to another. In fact, they all seem to individually pop out if you pull them. So, while doveweed looks like a grassy weed, it is not. And that is good news when it comes to controls.

As for chamberbitter, I'm often asked about a "fern-like" weed taking over a landscape. That's why it's best that chamberbitter, a broadleaf weed, be pulled up early and often, rather than treated with chemicals. They are essentially born with seeds, and it doesn't take long before those seeds are hitting the ground and reproducing. The more you yank out (and they pull up quite easily) and throw away, the less likely they are to reproduce. The seeds could still drop off even if the leaves are treated with herbicides.

Another interesting aspect to chamberbitter is that it behaves a lot like what we affectionately refer to as "sensitive weed." Like sensitive weed, if you touch the leaves of chamberbitter, they close up. And that makes it difficult to treat with weed killers — especially if you don't use a surfactant. If you mist the leaf surface without a surfactant in the mix, it will close immediately. Then, the herbicide usually beads up and rolls right off.

And the most obvious difference between sensitive weed and chamberbitter is size. Chamberbitter can get really tall and lanky. Sensitive weed pretty much hugs the ground.

So, back to controls: Both doveweed and chamberbitter can be treated at this time of the year with any 2-4D/dicamba or trimec-based broadleaf control like GreenLight Wipeout and Fertilome Weed Out. You can also spot-treat with liquid Atrizine products. In both of these cases, treatment early in the morning is essential because the summer sun can burn grasses nearby if the herbicide is applied in the middle of the day. And nearby grasses still may suffer minor phyto-toxic shock, because broadleaf weed killers are known for being caustic to anything and everything when temperatures rise above 95 degrees.

That's another good reason to avoid supposed cool-season herbicides with carfentezone. They will assuredly kill nearby grasses if used in these temperatures.

Another great control method, especially for doveweed, is the unique Garden Weasel AG Crabgrass Control. It's phenomenal on hard-to-control weeds like basketgrass and other grassy weeds. If you read the label closely, you might be surprised to learn how many broadleaf weeds it controls. But I don't have much confidence in it on chamberbitter, because of that "sensitive weed" reaction. You would need to wet the leaf surface first, and that means it will close up, making the powder ineffective. And, again ... it's better to pull up chamberbitter.

The best control measure, however, is actually prevention. Pre-emergent herbicides with benefin and trifluralin (Amaze by GreenLight, for example) and two-in-one pre-emergent herbicides like Dimension and Barricade will prevent these weeds. Remember the chamberbitter seed problem? A pre-emergent herbicide solves it.

Woodlands Home & Garden Show This Weekend at the Waterway Marriott GardenLine will be broadcast live from The Woodlands Home & Garden Show 6-10 a.m. this Saturday. The expo, which also runs on Sunday, doesn't actually open until 8 a.m., and that's when you can start dropping by the KTRH broadcast booth for some free goodies from me.

I will also being doing a seminar on heat-stress gardening immediately following the broadcast. And, as usual, almost everyone who attends my seminar goes away with a free product from one our great sponsors.

For more information on the home and garden show, the exhibitors, and the many additional seminars scheduled, see www.woodlandsshows.com.

GardenLine Listeners and E-mail Tip subscribers:
Purchase a copy of my book,
Gulf Coast Gardening with Randy Lemmon,
at a discount!

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