When we moved to Boise in 1971, I spaded the garden area a little at a time over the first winter. I noticed some weeds that I was not familiar with, and they came up in greater number in spring. I took one to the Extension agent at that time who identified it as “Russian Knapweed,” and he knew of the patch in my area. He advised me to pull it to kill it. I pulled those weeds for over 40 years, and then found that glyphosate would kill it.
Russian knapweed is on the Idaho noxious weed list along with 66 other weeds, including field bindweed, Canada thistle, and perennial sowthistle. “Noxious weed” means “any plant having the potential to cause injury to public health, crops, livestock, land or other property; and which is designated as noxious by the director”(of the Idaho Dept. of Agriculture). Russian knapweed is identified as an “aggressive invader” and toxic to horses.
In my yard now, quackgrass is trying to take over everything, invading all of my raised beds. It is not on the noxious weed list, and neither are hare barley, foxtail or squirreltail barley — all far more aggressively intrusive and more widely dangerous than Russian knapweed. I’m not sure which of the three barleys I’ve got in my paths between raised beds and on the perimeter of my garden, but they make Russian knapweed look like a kindly visitor.
These grasses apparently grow in winter, along with cheat grass, and right now are thrusting barbed awns or seedheads skyward, catching on clothing and dog fur and feet. The three barleys are all acknowledged to be dangerous to livestock eyes, ears, nose and throats in “Weeds of the West,” authored by Extension weed specialists in Washington, Oregon, California, Utah, Wyoming and New Mexico (but not Idaho, for some reason), and published in 1991. I don’t know why those grasses are not included in the noxious weeds list.
These barleys are new to my garden paths, having appeared just a couple of years ago, and having spread aggressively along the fence, outside the back fence and on my garden paths.
The plants, once mowed, persist in setting seeds very low to the ground. Seed cases (awns) are usually about an inch and a half long, stiff tan daggers aiming for dog feet, ears, mouths and eyes, and human clothes. Apparently we’re going to have to try to kill these grasses when they begin growing in winter.
Yup - time to think about fall gardening
I know it’s hot, but it is time to think of your fall vegetable garden. Although it may not happen as historical dates tell us, our average killing frost has been about Oct. 10. The past few years have seen extended mild weather later into autumn than that, but it’s a safe date to work from.
To plant something that will yield by that date, count backward. If a plant would be mature within 60 days, for instance, you’d want it to at least germinate by August 10. If you’re going to plant brassicas such as broccoli, cabbage, Piracicaba, collards or kale, for instance, you’ve got to plant seeds soon, even though these plants all tolerate quite a bit of frost. Their seeds, however, do not tolerate heat.
Plant their seeds indoors in sterile planting mix. Outdoors, the soil is so hot seeds may not germinate at all. Tomatoes and chiles or other peppers are technically perennials, but we grow them as annuals because they don’t tolerate frosts. Some folks dig, pot and overwinter chile plants indoors or in heated greenhouses, and others take a cutting of a favorite tomato plant and root that, growing it indoors over winter. Eggplants, new world beans (Phaseolus species), okra, squash, potatoes and some other plants die at the first frost. Sweet potato foliage is severely damaged by frost, and those potatoes should be dug immediately after a frost, or before an expected frost.
Send garden questions to firstname.lastname@example.org or Gardening, The Statesman, P.O. Box 40, Boise, ID 83707.