Q: Last year my bed of impatiens did so well and were so beautiful, but this year, the whole area looks sick and most of the plants are dying. I've watered it regularly and used fertilizer but it hasn't helped. Any ideas about what is going on and what to do about it?
A: After seeing the planting bed, which was quite large and noting that the disease had spread to the whole bed, I'm sure these plants have impatiens downy mildew. This is caused by a fungus-like microorganism called Plasmopara obducens.
•It is specific to Impatiens walleriana and does not affect other plants.
•Warning signs of infection are stunted growth, off-color, light green leaves, leaf and flower drop, and, eventually, stem collapse. There will be a white, downy growth on the underside of the leaves that can go unnoticed until it is too late. For that reason it is best to take a close look at the first sign of a failing plant.
•Once the disease begins it can spread rapidly through the rest of the plants. At this time the only known method of stopping it is to immediately pull the sick plant, or plants, remove the soil they were in, and add fresh soil to the site. It is even suggested that the sick plant be put in a plastic bag before throwing it in the trash. Additionally, any garden tools used, should be free of the soil and even cleaned with soap and water before working in that bed again.
•This disease can get started in early spring or late fall when temperatures drop at night and there is excessive moisture from rain or humidity.
•Just a note about watering and adding fertilizer to sick plants: Doing this often stresses the sick plant more. It is best to look for other causes before doing either of these things. This is true for any plant indoors or out.
Q: I bought what was advertised as stringless pole beans. They are prolific and produce a lot of large, healthy looking beans — but they all have strings. I'm looking for a truly stringless pole bean. Do you have any suggestions?
A: Here is an advertisement backed by reviewers who say this very long, delicious bean is “completely stringless”: “Fortex (Phaseolus vulgaris) is an early, dependable pole bean with an extended harvest period. Growing to over 11 inches, Fortex produces extra long, round pods. Early and very productive, the beans may be picked at 7 inches in length for extra slender, “filet” beans. Dark green, firm-textured pods are completely stringless and delicious at all lengths, even after the seeds enlarge.”
•You can purchase Fortex seed from Johnny's Selected Seeds, at www.johnnyseeds.com/p-6614-fortex.aspx.
•There are reviews on Johnny's page, and one is from a Master Gardener who says, “I can't say enough about how flavorful these beans are. They are tender, unstringy and have a great yield over a long period of time... My kids have pulled Fortex off the vines for years and snacked on them as well. They can tell the difference if I try a different bean. If I never had another bean variety to grow, this would be enough.”