Q: I put new, expensive potting soil in the pots for my patio tomatoes. The leaves curled, and the plants died. Will I have to replace the potting soil every year?
A: There could be many causes for the demise of your patio tomatoes, and determining what went wrong means you'll need to explore both the soil and tomatoes.
Tomatoes can be affected by various conditions, from soil that stays too wet to plants subjected to very cool weather. Tomatoes also can have curled foliage from attack by insects such as whitefly; foliage can turn yellow and die from various forms of viruses; and plants can falter from lack of certain nutrients. Your plants also could have been affected by drift from herbicides or other pollutants.
You must carefully consider which of these problems might be the cause of the failure of your crop. If this kind of problem happens again, you should quickly take a leaf to your local garden center and have the problem diagnosed while there is still time to remedy it.
Next, you must consider whether the potting mixture supplied adequate nutrients to the plants. Many potting soils are sterile and are formulated for indoor plants where the gardener intends to use a liquid fertilizer on a regular basis. These light mixtures provide a light, airy medium but little or no nutrients.
Some soils have added fertilizers, but they may not be adequate to grow tomatoes.
It is unlikely that your potting soil has a fungus, but it could.
There could even be a problem with the drainage in the pots that you used. Tomatoes do not like wet soil.
Review all of these suggestions. Then send some of your soil to the Agricultural Extension Service for testing (for instructions, call 855-6113). Testing can reveal if you have a soil problem. If you do not, you can save the money and effort of replacing it.
Email Pat Lea at firstname.lastname@example.org.