Plants start to die, then slightly recover, then become worse. The leaves...

Asked August 12, 2014, 2:25 AM EDT

Plants start to die, then slightly recover, then become worse. The leaves become yellow and/or white. I have zucchini, pumpkin, corn plants that have whitening or yellowing leaves. They are all dying. Pea and tomato plants suddenly stopped growing, then resumed after a few weeks. Miracle grow seemed to help at first, but now the garden is regressing. The pH has been between 5-6. How do I save my garden?I have many pictures, but this webpage only allows one. I can send more if you can provide an email address. Thank you for any help you can provide. David

Montgomery County Maryland

1 Response

When you have a problem that is affecting several unrelated species, then that usually suggests that the problem is not just a disease or insect (they tend to specialize and attach a species or family of plants.) So, look for a problem that would extend across species, i.e. environmental.
First, the pH is too low for a vegetable garden that likes a pH about 6.5. You need to use lime to bring the pH up. keep in mind that each number on the pH scale is 10 times the next on (so that 5 is 10 times more acid that 6.) When pH is too low, the soil can be full of nutrients, but the plants are not able to use them. We'd recommend that you get a soil test done by a soil lab (see out homepage photo of man holding soil) to get an accurate pH reading. Then you'll know exactly how much lime to add to your soil.

The basic soil test will also tell you if your soil needs extra phosphorus or potassium, important elements. Please go to Grow It Eat It on our website (right hand side.) Click on "Growing Vegetables" and read the profile on each of your plants. It has a wealth of information, including fertilizer guidelines.

The white leaves are powdery mildew. Read about that in "Vegetable Problems".