Most of the time we can treat our physical ills. Feeling feverish; take an aspirin. Suffering the discomforts of summer flu or colds; get the chicken soup going. Sometimes we run into more than we can cure with self-medication and end up heading to our favorite medical adviser. We tell our tale of woe, and the pieces of the health puzzle fall into place, and we’re provided with a diagnosis and advice as to how to get back on our feet.
Late July is about the time of the summer when plants show signs of not feeling their best. By doing some observing, gardeners can make a checklist of symptoms and find help from a plant M.D. source.
With some guidelines in hand, you can develop a checklist to help identify symptoms. Most problems involve leaves, flowers or fruit, but stems, branches and trunk also need to be inspected.
Know the name
You would be surprised how many gardeners look for an answer to a problem on a plant whose name they do not know. That doesn’t work. Some plant problems are specific to certain host plants, which helps to narrow the search.
Know the climate
We all know that weather conditions can drastically affect a plant — cold, hot, dry, wet, windy and of course our unexpected frosts. Do you know what growing conditions are ideal for your plant? You may have pushed the survival button too far. You’ll know soon enough by the shriveled, burned leaves that the plant should have been planted in shade or part-shade. A plant that is tall, spindly, pale green and without any visible damage generally has been planted in a spot that is too shady.
Our heavy-handed watering practice can account for sickly looking plants as well. An example is the split of skin at the top of a tomato, which is caused by heavy watering. Do you see plants with older leaves that have yellowed? Check the soil around the plant; if it is soggy, you are watering too much.
Time, weeds and insects
When did you first notice a sickly-looking plant? Has it been over a long period of time, or maybe just after spraying nearby for weeds or for insects? Maybe we can try to change our level of acceptance of a few annual weeds and damaging insects. If we kill all of the bad bugs with sprays, what will the natural good bug predators feast on? I think we should try harder to be comfortable with a few tattered leaves and an annual weed or two. Think of it as giving the balance of nature a chance. Besides, it’s a great education for a kid to watch a good bug capture a bad bug.
Look at the leaves
Leaf damage can be complicated, so it is important to be observant. If you take a sample to one of the Oregon State University Extension Plant Clinics, make it a fresh one.
Does the leaf have holes or chewed edges? Take time to look for pests on the top side of the leaf and on the underside. It could be weevils, beetles, earwigs, caterpillars or one of many insects (an insect has a jointed body, six legs and a hard exoskeleton).
Rounded spots, speckles of any size, can be caused by spider mites or thrips. The spotting can also be caused by powdery mildew, black spot, leaf spot or rust. Caterpillars and loopers are responsible for “skeletonizing” leaves (soft tissue is eaten away; tough veins remain).
Puckered, bubbled, cupped, curled, stunted, twisted, bumpy and warty are good words for a symptoms list.
The same checklist process can be applied to plants with problems on the stems, trunk or branches.
Be observant. Is the whole stem discolored, dying or dead, or just a small portion? Does the stem have holes or is it chewed, split, cracked or broken? Stems can have weird lumps, bumps and warts, and stems can have holes in them caused by borers.
In our instant and quick-fix society, we may be tempted to grab a bottle of insecticide or pesticide and supposedly solve our problem. The danger is that along with killing the culprits, we are also killing the natural predators, the good bugs. Timing of the spray is critical. If the pollinators are out doing their work and they catch some of the spray, they will more than likely be killed.
A chewed leaf on your favorite flower may not appeal to our aesthetic side, so remove it. The plant roots haven’t been damaged, so a new leaf will appear.
Start digging, or dousing
Scratch the soil surface and you may find a worm that is causing leaf damage at night. Remove it and keep checking for a few days.
Aphids are a common problem, and the most common solution to eliminate them is using your garden hose to blast the plants with a harsh stream of water.
Many gardeners use row covers to keep out leaf-eating pests or egg-laying pests. Row cover is a light-weight white fabric that can be draped over crops or over a rigid frame. The fabric breathes and allows light to reach the plants. Row covers are available at garden centers. There are several grades of fabric available. The heavier fabric is used for frost protection.
Take it to the doctor
Ailing plants can exhibit an abundance of symptoms for which a “chicken soup” remedy ideally can be found.
OSU Master Gardener Plant Clinics are held in Deschutes, Crook and Jefferson OSU extension offices. Bring fresh samples of the damaged plant material. Bringing a live pest is also helpful, if possible. Check with your local office for staffing times.
Several books that I find extremely helpful are “What’s Wrong with My Vegetable Garden?” by David Deardorff and Kathryn Wadsworth, and “The Vegetable & Herb Expert” by D.G. Hessayon. Check out the OSU publications at http://extension.oregon state.edu/deschutes.
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