This disease appeared on one tomato plant, which I removed. It’s now spreading to other plants in the same bed. Help, please.
This is the fungal disease Septoria. It’s common on tomatoes, and the management is similar to early blight, another tomato fungal leaf spot. In wet years, it is hard to keep up with fungal problems. If you do not have too much infection per plant, pull off heavily infected leaves before you apply a fungicide. If they are heavily infected, you may want to consider replanting; it's still early in the season. The fungal spores of both these diseases overwinter on seeds, infected plant debris and in the soil. As soon as you plant, mulching can be helpful to keep spores from splashing onto plants. To form a solid barrier to the spores, use 3-4 layers of newspapers deep and overlap, then weigh down with straw or other mulch. There is a list of management practices on the HGIC website. Search there for “septoria” or “early blight.”
In the past, I have used netting to keep birds from getting to my raspberry and blackberry bushes. This year I purchased a product online called floating row cover. It’s supposed to allow 90 percent of sunlight and keep off birds. (And Japanese beetles!) Do you think it will be OK to use? I do not want lose berry production.
We would advise against using floating row cover all summer. It can cause heat buildup under the cover, which can stress plants and lead to other problems. The plants also need to be accessible to pollinators. A good alternative, in this situation, would be tulle fabric laid over the top of the plants when the fruits are full size but still green. Yes, tulle like in tutus! This fabric is lighter, allows good air flow and protects from bird feeding. You can find tulle in fabric stores or online.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Maryland’s Gardening Experts” to send questions and photos.