Q: Am I ever going to get rid of the weeds in my garden?
A: Control the weeds? Yes, and without too much time and effort. Get rid of them? Never. Think of it this way: weeds are wild plants looking for the best place to put down roots. You spend time and effort every year improving your garden soil, making it the best place for plants. Why wouldn’t every local weed notice your garden soil and try to take advantage of it?
And weeds are not wimpy plants, or we would never hear of them. Weeds all grow quickly and spread widely. They all are tough competitors which can push other plants aside or climb over the top of them. Weeds are champions at reproducing themselves by spreading their roots widely and by creating astronomical numbers of seeds.
Garden plants, both vegetables and flowers, have all been bred for a particular purpose. In that breeding they may have lost some of their original weed-like strength, traded off for a gain in beauty or flavor. Lettuce would be a good example. It is hard to imagine how gardeners tens of thousands of years ago could have seen any promise of food in the weed we call prickly lettuce. But that weed, with tough, spiny leaves on a tall stalk, was bred until it became our garden lettuce.
If that seems hard to believe, watch a spot where you know that prickly lettuce grew last year. The first small rosette of leaves on the ground will look like a baby plant of garden lettuce because they are its wild ancestor. Let prickly lettuce grow in the same bed as Salad Bowl or Black-seeded Simpson lettuce, though, and the original version will take over.
Weeds arrive in our gardens as seeds. They blow in on the wind or float in on water from irrigation ditches. They hitch a ride on an animal’s coat or the sole of a shoe. Weeds also may arrive as seedling plants, hiding in nursery pots with purchased plants. Since none of these sources will disappear, we always will have a ready source of new weeds. And weeds by definition are opportunistic plants. Whenever offered a chance to grow, they will. They also are adaptable plants, unlike our garden vegetables and flowers, which are fussy about sun and shadow, wind, soil temperature and quality, moisture and dryness.
With all those advantages built into a weed, how can it possibly be easy to control weeds? Simple: take good care of the garden plants. The better you care for your plants, the fewer weeds will find a place to grow.
Most of the problem weeds around here are annuals. That means that every one of them is stopped in its tracks if it does not make the seeds to perpetuate itself. Therefore, a major weed killing weapon is to cut down weeds before they can ripen seeds. Since many can grow and mature their seeds quickly, cutting them as soon as they bloom is a good precautionary step.
Do not till any more than necessary. Virtually all weed seeds require light to germinate. Buried in the ground, these seeds may live for many years but cannot sprout in the dark. Only when the tiller blades bring them up to the surface light can they begin to grow.
Grow garden plants close together. Cover the ground as well as possible, so that weeds are shaded by deliberate plantings. Of course that does not mean to crowd flowers or vegetables to the point where they compete with each other, but bare ground between plants is an invitation to every weed. Mulch the ground between plants to cover empty spaces. Plant annuals as ground cover between perennial flowers.
To get rid of the weeds which do appear, simply cut them off. Either they will die or they will be made unhealthy from losing their leaves. If a weed starts to grow again, cut it again. Even for the most tenacious of perennial weeds, like horsetails, this is the most effective and easiest way to combat them.
Do not bother spraying herbicides in gardens. We have been trying herbicides for 70 years now, ever since they came on the market at the end of World War II. If herbicides were an effective weed deterrent, we would have seen great results by now. They are used in the huge areas of farm fields, but this agricultural technique does not apply well in gardens.
A few other kinds of weed killers have limited success. Burning weeds with a weed torch works best on small weeds. I find a torch useful for killing — or at least slowing down — creeping knotweed in a gravel driveway. Weed torches have to be used with care around dry vegetation, wood, and plastic.
Vinegar spray burns individual weeds in the same way as fire. It is most effective on dry, sunny days, and it must be used with extreme care where the weeds live among valuable plants. Vinegar burns whatever it touches. Corn gluten meal as a pre-emergent herbicide has worked fairly well in the Midwest but has been ineffective in the West. It probably is not worth trying here.
If there is an underlying principle to weeding, it is to remove the top growth before it produces seeds, and to do so without disturbing the soil.
Q: Is there any way to keep Oriental poppies looking good for longer? The petals drop. The bare stems are homely. The leaves turn yellow.
A: Poppies have a glorious but brief moment in early summer. Their new growth in late summer is a refreshing young green. For the intervening weeks they are not a decoration. The usual recommendation is to grow some other flower which hides the poppies in midsummer. There is no reason to leave a stem once the flower has shattered, although it is important to let the leaves mature.
Recently I read an article by Helen Dillon, the garden writer from Ireland. She has decided to stop growing the Oriental poppy called ‘Patty’s Plum.’ She says that its beauty is so short-lived as to not be worth it. She found herself checking it every morning to see whether the flowers had fallen apart overnight. She felt obliged to rush out with pruning shears in hand the minute the petals fell because the remains were so unattractive. She is going to replace the poppies with something less flamboyant but longer lasting.
I will be leading a discussion group at the fair, entitled Better Gardens Every Year, in the Agriculture building. The program will be at 1:30 p.m. on Thursday afternoon, and questions will be welcome.