Weather ups and downs have created some challenges in the garden this season. On a good note, moisture levels are up year-to-date so maintained landscapes are green and happy. The down side is pests, diseases and cultural damage. The best offense is correct identification of the problem then action to maximize a good outcome.
LIFE IN THE GARDEN
Whatever weather-related problems your landscape is having, surely you’ve got something positive going on. Take the time right now to enjoy being outside. Water lilies, sunflowers, black-eyed Susan, phlox, bee balm and many more plants are in spectacular bloom right now. Stop to savor them, even if it’s a single minute.That’s why we garden — to center ourselves in the moment.
HEALTH CARE FOR PLANTS
Here are some terms horticulture people, the doctors of plant life, often use: integrated pest management (IPM); best management practices (BMP) and plant health care (PHC). They refer to proactive strategies that foster good plant health and problem-solvers that minimize negative impacts on the surrounding environment. They work on the principle of giving plants every possible chance to thrive, because healthy plants naturally have fewer pest and disease problems.
You’re probably already using some of these best practices: Choosing the right plant for the right place; improving and conserving soil; efficient watering. Here are a few more: planting at the right time, choosing adapted varieties; mulching; pruning correctly; and (perhaps most important) paying attention.
If you do all of the above, you’ll likely minimize the time you’ll spend on the last best practice: managing pests, diseases or other problems.
When problems do arise, there’s a best process: First, identify the plant. Then, try to identify the problem — which insect is it? Was the tree planted too deeply, or is the soil around it compacted? Then you can choose the best actions to take.
Here’s a common example: herbicide damage. The drift from weed sprays travels quickly and far and can easily cause damage to plants’ leaves. This happened to my green beans last summer, even though the spraying took place across the alley. I had thought the severely wrinkled leaf might mean insect damage. By identifying the cause, I was able to avoid further stressing the plant by spraying for insects it didn’t have.
LANDSCAPE TROUBLE SPOTS
Earwigs are on the prowl in high numbers because of the wet weather. During the day, they hide under pots, in mulch or wherever it’s dark and moist. At night they feed on flowers including marigolds, petunias and hostas. Despite their ick factor, earwigs also feed on mites, insect eggs and aphids. Keep them outside where they belong by keeping areas close to doors free of moisture and hiding places. You can trap them with rolled up cardboard or newspapers, then bag and toss. Another trap: sink plastic containers filled with vegetable oil around the yard so they’ll crawl in and drown.
Leaves are falling in midsummer. The spring rains brought on heavy leaf growth, then when the weather turned warm and hot, trees couldn’t sustain that many leaves, so they dropped them. Heavy rain may be causing leaf drop, too. Trees need good drainage and prefer deep, infrequent watering that lets soil dry out a bit between. Be careful not to overwater, especially trees that are located in turf.
Inspect trees for disease. Cystospora canker on stressed aspen, peach, spruce and other trees and shrubs is now showing up. This fungus grows on trunks or branches and causes darkened, sunken, oozing sores that weaken the tree and attract pests. Removing infected limbs, sterilizing tools between cuts, or if the limbs are large, consult a certified arborist.
TOMATO WOES
In addition to fungus and bacterial infections, tomatoes can suffer from sunscald, leaf roll, cracked fruit, cat-faced fruit and blossom end rot. And the dreaded psyllid, an insect pest that plagued many gardeners last year, can show up anytime. But integrated pest management applies to tomatoes, too — perhaps to tomatoes especially. Take photos of the problem and confirm its ID with a Colorado State University extension office or trusted garden center.
Last week I covered three tomato diseases. Another to consider is spotted wilt virus. The symptoms start out as dark-brown to purple spots on leaves. These dark areas spread to the stems and form cankers. As it spreads, leaves become stiff and fruit develops funky-looking rings or spots. The virus is carried by western flower thrips. There is no cure. Pull the plant out immediately; do not compost.
Tomato leaf roll is common; most of the time the culprit is irregular or excessive watering, heat, or severe pruning. Starting at the bottom of the plant, lower leaf edges roll inward, sometimes touching. In time the leaves can thicken and become leathery, but they remain green. This does not affect plant growth, yield or fruit quality.
Cracked fruit and blossom-end rot result from irregular watering. Cat-faced or puckered-looking tomatoes are caused when fruit sets during cool temperatures (yeah, we’ve had those, too). Just cut off the damaged parts and and enjoy — subsequent fruits should be just fine.
Psyllids, an insect pest, fly in from the south. Some years are worse than others and some gardens never get them. The pest injects its toxic saliva into tomato and potato leaves, which then turn yellow with purple veins. Once fully infected, the leaves stand on end. You can sometimes see psyllid nymphs — the life stage before adults — on the undersides of leaves, when they are yellow. Their excrement looks like sugar granules sprinkled over the plant.
Fruit ripening seems slow this summer, cherry tomatoes being the exception — and there’s no cure except time and patience. But home-grown tomatoes are usually worth the wait.
Betty Cahill: http://gardenpunchlist.blogspot.com/