Observe Symptoms, Diagnose Problem, Apply Treatment
Summer’s heat and dry conditions subject plants and lawn to a variety of problems. Here are some common plant ailments and some first-aid techniques you can try to help them:
* Leaves at base of plant turn brown, then fall off.
Diagnosis: Look at underside of leaf with magnifying glass. If tiny little spots appear, the problem is spider mites. Or shake the leaf over a white piece of paper. Spider mites will scurry away.
Treatment: Wash undersides of leaves with water for at least three days. Spider mites drown easily. Promote good air circulation by not crowding plants in landscape or removing thick foliage or stems from center of plants. If untreated, entire plant can quickly lose all its leaves. Roses are especially likely to be affected.
* Leaves turn yellow and then fall off.
Diagnosis: Examine soil and entire plant. Yellow leaves can be a symptom of overwatering. It can also be a sign of nutrient deficiency.
Treatment: Soil should dry between waterings. Allow plant time to recover and sprout new leaves before fertilizing.
* Leaves are brown around the edges and look scorched.
Diagnosis: Scorched leaves can be a sign of sun scald.
Treatment: Evaluate entire plant and its location. If the plant is in the ground, it may be receiving too much direct sunlight. Cover with shadecloth. If the plant is in a container, move to an area of less intense sunlight.
* Leaves are wilting.
Diagnosis: Improper watering. Put your finger in the soil to determine how moist the soil is. If the top few inches are dry, water.
Treatment: Water thoroughly so water reaches plant roots. If plants are in containers, immerse containers in water until bubbling stops. Or let water slowly soak through entire plant so entire rootball is wet.
* Leaves have holes in them.
Diagnosis: Insects are munching on them. Large holes, entire leaves or sometimes flowers missing can mean grasshoppers have moved in. Examine the plant and surrounding area to determine what type of insect is at work.
Treatment: If the problem is grasshoppers, spray landscape with a commercial product such as Grasshopper Attack. Alert your neighbors because grasshoppers can infest an acre or more.
Other insects also chew leaves. If the damage is more than you find acceptable, spray with commercial insecticidal soap according to product directions.
* Water runs off the soil surface.
Diagnosis: Look at the soil surface. Is it hard and caked? Take a trowel or shovel and dig down a few inches. Is it easy to work the soil? If not, the soil is crusted and water can’t penetrate to the plant roots.
Treatment: Cultivate the soil to break up the crust. Add a layer of mulch, four to five inches thick, to shade the soil and plant roots, improve water retention and reduce weeds.
* Despite regular care, plants in containers still don’t look right.
Diagnosis: Check size of container in proportion to plant. Is the top growth larger than the container? Look underneath. Can you see roots emerging? Pull the plant out of the container. Are the roots a thick, coiled mass?
Treatment: Shoulder and shift. Remove the plant from the container. Trim back rootball from bottom and edges. If the plant is still in scale with the container, repot with fresh potting soil. But most likely, it’s time to shift the plant to the next largest size container. Water well to thoroughly wet potting soil and root ball.
* You water regularly, but plant leaves look yellowish-green or even yellow.
Diagnosis: Lack of fertilizer
Treatment: Use a commercial liquid fertilizer, according to package directions. Be sure plant soil is moist before fertilizing. Never fertilize a plant stressed by lack of water or excessive temperature.
* Grass is dull and crunches when walked on.
Diagnosis: This is usually the first sign of stress from lack of water. Probe the grass to check how dry the soil is.
Treatment: If it is dry, water deeply and infrequently. Water a few times a week, for at least 15 to 20 minutes, depending on type of grass. Adjust mower blades so grass length is longer in summer to conserve water. Remove thatch build-up so water can penetrate.
* Brown patches in lawn.
Diagnosis: Uneven watering or insect infestation. Check watering system to be sure lawn is evenly irrigated. If watering isn’t the problem, take a sample of affected lawn to a local nursery for assistance in identifying what is.
Treatment: If lack of water is the problem, adjust irrigation system. If insect infestation is occurring, treat accordingly. Some pests, such as chinch bugs, are controlled by a naturally occurring fungus that develops in moist soil and can be controlled by keeping a lawn well watered.