The DeKalb Extension Garden Patch

A gardening problem from Hilde Friese:  I raised cucumbers from seeds. When the plants were about 12 inches tall and very healthy looking, one day, two out of three plants got “weak” spots at the soil level and fell over and withered away within hours. I could not detect a critter that might have chewed on it. I have grown cucs in large pots on my deck with great results and good harvest and never had that problem.

Hilde, it is often not easy to diagnose a problem without seeing the plant - or at least some photos. This spring has been particularly hot, which has resulted in some problems showing up earlier in the growing season.

One possibility would be that the early heat prevented you from “hardening off” your seedlings, and they were exposed to high temperatures too quickly to become heat-resistant.

Another likely cause is “damping off." If the pots were kept very damp it would be possible that the plants succumbed to this soil-borne fungus, which causes the lower stem to weaken, and the plant to die. Lesions at ground surface and below ground are visible and these encircle the stems. The possibility of “damping off” is reduced if seeds are planted at temperatures above 60 degrees.  This happens with many types of seedlings and young plants.

Another, less likely, possibility is that vegetable pests were around earlier than normal, for example, cucumber beetles. These can infect the plants with bacterial wilt as early as the cotyledon stage, and this causes the plants to wilt and die.

Fungus gnats, according to UGA sources, are more of a nuisance than anything, particularly on houseplants and in greenhouses. They are short-lived, and common on soil surfaces that are kept damp. They are weak flyers, and are often seen  running over the soil surface. Their larvae feed on decaying organic matter and fungi in the soil, and they generally don’t damage plants.

For larger plants, vine borer would be the most likely problem, but probably not for 12 inch seedlings, and the entrance hole of the borer is very visible!

My large ash tree has two main trunks near the top. Is this a safe situation or do I need to consult an arborist?

That is a very weak branch structure and it poses a potential hazard to anything located nearby like a house, a car or a neighbor. The central point where those two branches attach is often a point where water collects and where decay gets initiated. This further weakens the connection, and over time, as you get more weight or you have heavy wind or an ice storm, this tree can split in half and cause a lot of damage.

We recently looked at a tree that did just that and broke off causing damage to the house roof and a car.  -  Gary Peiffer, DeKalb Extension Agent

Some tips for July gardening:

-  Last chance to set out fast bloomers for fall - zinnias, petunias, marigolds can be put out now.  And impatiens will provide a bright splash of color in the shade.

-  Keep your young trees watered deeply and mulched - but keep the mulch off the trunks of the trees.

-  Pick your vegetables such as squash and cucumbers when they are young and tender.  This will keep the plants producing - and they taste much better!

-  Keep your sprawling vegetable plants and ripening vegetables off the ground.  This will allow better air flow around them, and will keep the fruits from rotting.  It will also help to prevent soil-borne diseases. Trellising is good!

-  Believe it or not, by the end of the month you can start seeds indoors for September planting. Check the planting chart on the UGA publications website:   www.caes.uga.edu/publications

Add your questions to the comments box - or email the DeKalb Extension Master Gardener Office -  dekalbmastergardener@dekalbcountyga.gov. We'll be happy to help. A Master Gardener is on duty from 8:30 a.m. - 5:00 p.m. Monday through Friday.