Here are this week’s gardening questions and answers, provided by Parker County Master Gardeners. To submit a question, send it to firstname.lastname@example.org. For more information about Parker County Master Gardeners, or to become a member, call 817-598-6096 or visit www.pcmg-texas.org.
When I walk under my crepe myrtle, I feel something like rain falling down; but I cannot see what’s causing it.
You probably have an insect called a glassy-winged sharpshooter that sucks juice from the leaves. The sprinkle of moisture is known as “honeydew.”
They seldom do much damage, and insect control is not warranted in most cases. Rarely, severe infestations may lead to a disease called “sooty-mold,” which makes the leaves look silvery. This is a fungal disease.
If you do see extensive damage, you can control sharpshooters by spraying with an insecticide containing acetamiprid; and treat sooty mold with a fungicide.
The bottoms of my tomatoes are black and hollowed out. What’s going on?
This is a symptom of blossom end rot, caused by uneven (too much or too little) moisture in the soil.
If tomato plants do not get consistent moisture, they develop a calcium deficiency. To control this, make sure the plants receive 1 inch of water every week, including rainfall.
My vinca ground cover has died. What caused this, and what can I do about it?
Vinca, canna and several related plants are being attached by an insect called leaf-roller. This caterpillar lays eggs on a leaf and then roles it up in order to protect them. This causes the leaf to die.
You can control the insect with an insecticide containing Bacillus thuringiensis (BT), a bacterium that only kills caterpillars. If it is too late to spray, don’t worry. These plants are hardy perennials, and should recover from the infestation later in the year.
If the plants are unsightly, you may mow or weed eat to improve the appearance.