“Ask the Plant and Pest Professor” is compiled from phone and email questions asked the Home and Garden Information Center (HGIC), part of University of Maryland Extension, an educational outreach of the University of Maryland.
Question #1: What’s the latest on impatiens downy mildew disease? Are you advising against planting impatiens again this year? Is there some way I can treat my soil so that I don’t have to worry about the disease next year?
Answer#1: There have not been any recent updates about impatiens downy mildew. But, we still are recommending that impatiens not be planted this season. Nursery growers have been producing fewer impatiens and they are not as available for purchase because of this disease. On our website we have information on impatiens downy mildew and a list of replacement plants. On our homepage click on ‘invasives’ then ‘invasive diseases’. It is not feasible to treat the soil to prevent the disease. There are no labeled fungicides for homeowners for this purpose and windborne spores can blow into your yard to infect your plants.
Question #2: I was wondering if you had recommendations for the best kind of backyard composter for kitchen scraps.
Answer #2: There are quite an array of enclosed bins and tumblers designed for kitchen scrap composting. We have not evaluated them but you can find this information online. It is even possible to make compost by simply burying the scraps with other organic materials like leaves or straw in an open compost bin. Check with your county Public Works Department/Recycling Division; some will provide homeowners with a free bin. Or if you wish to build one, you could purchase a 10′ length of 3′ high fencing material (having a grid system of 2″) and wire the ends together creating a cylinder. You could also use three or four shipping pallets wired together to form an open cube. The minimum size for good results is 3’x3’x3’. Another option for composting kitchen scraps is vermicomposting (worm composting) indoors. Look for publications HG35 Backyard Composting and HG40 Indoor Redworm Composting on the Home and Garden Information Center website, for additional information.
Question #3: Can you please tell me why most of the Leyland cypress trees in our area appear to be dying? Is there some kind of disease going around or were they injured by the cold winter? But, they seemed to have made it through the winter okay so I do not think that is the reason. Is there something that can be done to save these trees?
Answer #3: Many Leyland cypress trees in the Maryland area were killed or suffered winterburn from the severe winter. They can get diseases but the dieback we are seeing on a wide-spread basis this spring is because of the winter. Although Leylands are supposed to be hardy to Zone 6, some cultivars are not that hardy and are not labeled as such. Also, trees that might have been stressed or not growing vigorously, but didn’t show any obvious symptoms in the fall, may have been extra-susceptible to the low temperatures. Unfortunately winter damage is not reversible. If they are not putting out new growth and the dieback is continuing the trees probably cannot be saved. If they need to be replaced, plant Arborvitae ‘Green Giant’ instead.
To ask a home gardening or pest control question or for other help, go to https://extension.umd.edu/hgic Or phone HGIC at 1-800-342-2507, Monday through Friday, 8 a.m. to 1 p.m. Follow us on Facebook and Twitter.
Ford Schumann says
In the interest of helping us all get to Zero Waste, Infinity Recycling has excellent compost bins for sale at very low prices, and they include a helpful booklet on composting.