Virginia buttonweed and doveweed have become the two most invasive and frustrating weeds along the Gulf Coast at this time of year. But they can be dealt with even in the summer heat – if you spot treat.
You can’t just spray an entire lawn. Last weekend on GardenLine, I promised that I would explain further in this week’s article, so here we go.
Some people believe the old notion that these weeds can only be controlled with cool-season herbicides. However, there are some new products on the market labeled for use on Virginia buttonweed. And since it and doveweed are very similar in leaf structure and growth patterns, these new herbicides should work on both.
However, there’s a big BUT with their use in our Texas summer heat. You can SPOT TREAT only!! The fewer grass blades you spray, the less likely you’ll see the grass yellow. Last year, when I researched alternatives to cool-season herbicides, I thought that I’d found a product or two that could eliminate the need for the standard solution: just pull out as many weeds as possible and then wait for cooler weather. But in the year that has passed, I’ve found that I don’t really have much confidence that the products won’t damage grass in our high summer heat. So, I emphatically instruct that applications should be only done very early in the morning or on non-windy evenings when things have cooled down a bit.
The best control regimen for Virginia buttonweed and doveweed is still - and not just according to me, but according to other herbicide experts - to pull up as much as you can until the time when cool-season herbicides are permissible. You may have been hoping to hear about some innovative new herbicide that would wipe out Virginia buttonweed and doveweed right now. But I haven’t been able to find a “silver bullet.” Those I’ll suggest have no empirical research that guarantees them to be totally safe for St. Augustine, Bermuda or Zoysia.So, proceed with caution.
The only recommendation I have ever felt comfortable with is AgraLawn Crabgrass Control. It works on Virginia buttonweed and doveweed, but using it is tedious at best. The organically derived powder smells like cinnamon toast, and it’s a pain to apply - you have to wet the blades, preferably with a surfactant, and sprinkle the powder on them individually. It’s easy to waste the powder, and a $20 container only covers 100 sq. ft.
That’s why my best advice is to wait for cool-season herbicide time arrives … likely not until late October. Until then, pull out all the Virginia buttonweed and doveweed you can. Make it a daily or weekly routine. When you walk the dog, pull out some out. When you check the mail, pull some out. In my estimation, it is better to pull out what you can, when you can, rather than allow either weed to overwhelm an area.
The cool-season herbicides that I have long touted are Fertilome Weed Free Zone and Bonide Weed Beater Ultra. Still, we are nowhere close to the time when we can use them with confidence - they will flat-out kill grass when used in high heat.
In the meantime, here are a few herbicides that have been recommended for Virginia buttonweed control, but that have no studies showing they’re safe for the existing grass. Be forewarned, too, that a couple of them are ridiculously expensive. And it’s worth noting that most will never be found at big box stores. In fact, the expensive ones will likely only be found at feed stores, specialty garden shops and mom-and-pop nurseries and garden centers. If one of those retailers doesn’t have any in stock, they can probably order them. I’ve listed them from least expensive to most costly.
- Top Shot Herbicide (Probably the most cost-effective)
- Fahrenheit (A cheaper version of Celsius)
- MSM Turf (Often called Manor)
- Celsius (Known to be the most expensive)
And one last warning above and beyond possible grass damage: Do not use these products around the base of any tree. As with atrazine, they are known to cause grave damage to tree root systems.
Still, if you feel like giving them a try, I’m always excited to hear about listeners’ “case studies.” Call me this weekend or send me an email if you are inclined to experiment with them.