Among the many great things about living in a desert is that we get precipitation infrequently, but in big spring and autumn downpours. Once we see a good cloudburst, it’s almost guaranteed that there’ll be a flush of wild flowers later. Whether we’re enjoying them in a park or a canyon, they’re gorgeous – and amazing.
While we do really appreciate these floral displays, there are other, less welcome plants that also appear. Weeds arrive in their unwelcome multitudes. I’m not talking so much about noxious and invasive weeds. They’re the plants that can cause major environmental problems. Some of them can take over our wild lands and crowd out native species. As if that weren’t bad enough, when those native species are gone, the animals that have been using them as food or as a home will lose out. Grass weeds, like red brome and cheat grass, become standing dry fuel, increasing fire risk.
Today, I’m just talking about “landscape weeds”, or “nuisance weeds”. And not just one type of weed. We have a terrific variety of them here in southern Nevada. You’d think we were living in a lush environment! Who’d ever believe so many weeds could pop up almost instantly? In a desert!
A week ago, my yard appeared, if not pristine, then at least relatively weed free. Over the weekend, after an inch of rain, I looked at my yard again. A plethora unwanted plants: narrow leaf plantain, few kinds of mustards, several types of thistles, Bermuda grass from somewhere, and of course, the occasional dandelion.
If it were a small infestation, I’d have have a couple of choices. One is to take my household steamer, aim the narrow nozzle at the base of the plant and boil the sap. This is safer than using flame, which works, but it means carrying around a tank of propane, a fire risk for sure. I could just pull them out or hoe them out, but my poor knees and back couldn’t stand the amount of pulling necessary to get rid of them all.
It’s at times like this that we’re tempted to reach for the herbicide. That’s the stuff usually labelled “Weed killer”. Don’t be fooled; these products are designed to kill plants.
If the product says that it kills broadleaf and grassy weeds, that means it may kill grasses (the ones you want as well as the ones you’d like to remove) and non-grassy plants, like thistles and mustards. However, they’ll also damage other, desirable plants. For instance, an herbicide that controls weedy mustards can also do damage to your broccoli and kale. By the way, I just read that some weedy mustard seeds can live in the ground for up to 50 years.
In my little garden kingdom, I have filled almost every inch of space with plants, from fruit trees to vegetables and herbs, along with roses and pretty flowering vines that’ve begun to grow and bloom wildly. Since there’s not much space between plants, I can’t use an herbicide, for fear of damaging my crops.
Too many people don’t seem to realize that just because you aimed the sprayer at one plant, doesn’t mean the spray won’t reach another plant you hadn’t intended to kill. This is a big problem when someone sprays on a windy day. Those chemicals can go anywhere.
What do I do? There’s a product called “horticultural vinegar”. Technically, it’s not vinegar because it’s got far more acetic acid than household vinegar. Horticultural vinegar kills plants from the top down. It doesn’t get into the plant’s circulatory system. It can only kill what it touches, so it’s not likely to drift onto other plants and damage them. It’s not perfect, unfortunately, especially if a weed’s been in the ground, growing a vigorous root system for a while, or it’s a big plant. This stuff is best on small weeds that you can cover completely.
If you must use an herbicide, remember this helpful hint: READ THE ENTIRE PRODUCT LABEL- it has all the essential information about using it safely.
If you really want to learn more about weeds, there’s a two-volume compendium entitled “Weeds of California and Other Western States”. It’s published by the University of California. It’s not cheap, but it’s comprehensive.
Get outside, enjoy your spring. You know it doesn’t last very long.
For KNPR’s Desert Bloom, this is Dr. Angela O’Callaghan of the University of Nevada Cooperative Extension.