Out-of-control summer vines need attention
folded leaf thrips. When you pry the leaves open, you notice the cream to black hairlike thrips, which are rasping sucking insects. If you hit the insects with the soap spray you will obtain good control, but that is almost impossible when they are hidden within the leaves.
Probably your best control is a systemic insecticide applied to the soil that moves through the roots, up the trunk, into stems and to the leaves. Most major brand products offered for pest control at garden centers have a tree and shrub insecticide that can be utilized, following label instructions, for container plants. One application is likely all you need.
My zinnias get dry spots in the leaves that are slowly affecting the entire planting. What should I do?
Several leaf spots affect zinnias during the hot, damp summer season. These include bacterial leaf spot and alternaria leaf spot. They look similar and produce dry-looking spots that can merge together. Zinnias grow best during the drier spring and fall weather. If they grow into the more moist months a copper fungicide applied as instructed on the label may help reduce the leaf spot damage to foliage. Some zinnia varieties also appear less susceptible to these diseases, so try different selections for fall or spring.
I notice petunias are present, but pansies are missing from your October plantings. When can we enjoy these colorful flowers?
Wait just a little longer for the ever-popular pansies and viola relatives to arrive at garden centers. These flowers need the much cooler weather that could arrive during November. If pansies do not have the more accommodating weather, they grow lanky, develop diseases and decline. Even petunias grow thinner and longer stems with small blooms until the consistently cool weather arrives. Both of these plants won’t mind a frost and pansies withstand freezes. Regretfully, pansies only last until early March — when the weather becomes too hot for their good growth — whereas petunias grow through May.
I have been raising tomatoes in the same area for many years and get white lines in the leaves and also nematodes. I am about ready to just buy my tomatoes unless you can help?
Stores have plenty of red, ripe tomatoes, but they are never as good as the ones you produce in the garden. Also, you can do it a lot cheaper. Let’s start with the white lines in the leaves, which are a yearly problem caused by the leaf miner insect.
Some leaf miner damage can be tolerated, but when the leaves begin to fill with the squiggles, it is time to take control. A quick and easy cure is the natural spinosad-containing insecticide found at many independent garden centers under several brand names. Apply as needed when you cannot stand the leaf damage, following label instructions.
Nematodes, which are root-damaging roundworms living in the soil, can often be controlled with resistant varieties. Look for an ‘N’ next to the variety name on a label or seed packet that notes the plant offers some resistance. If you are planting a variety susceptible to nematodes or just want to ensure getting a crop, remove soil from a spot up to two feet in diameter and eight inches deep and replace it with potting soil before planting.
My clumps of geraniums look almost nude, but I expect them to grow back. Should I cut the stems back and how severely?
Many geraniums, and especially those in containers, make it through the hot, wet summer months to revive for fall. You can trim the bare but green stems back some, but leave a good branching structure to begin growth. Keep the soil moist but not overly wet and apply a slow release fertilizer to do the feeding for several months. With this care, they should be producing lots of new growth as the weather cools, and you can do more grooming if needed. When the plants regrow new roots, they may also need a larger container.