I'm losing one blue spruce after another. Branches die at the base near the trunk, though tips stay green at first. Then it works its way up until the entire tree dies. It takes a few years. I don't see any signs of insects. They're planted on a hill in clay soil.
Cytospora canker disease is extremely common on blue spruce. This fungus targets blue spruce stressed by drought or poor site conditions. Spores invade through openings such as mower wounds. Older (lower) branches are more susceptible than younger ones. Symptoms include resin flow on dying branches that dries to flaky white patches, sometimes with black spots (spores) nearby. Fungicides are not effective. Pruning off infected branches can stop its progress up the tree, if the fungus has not gotten into the trunk. Remove any infected branches or trunks from the site. Call us or see our website for more information.
Parts of my front yard are so full of compacted clay that neither weeds nor grass will grow. Can I till in some compost now, well before I plant in spring, or will I just be wasting time and money?
Winter soil is usually wet, because low air temperatures don't cause moisture to evaporate quickly. Working in wet soils containing clay can destroy soil structure, making it brick-like for years. Keep in mind that late August-early September is the best time to plant grass seed. Spring-planted grass often doesn't make it through the summer, which really wastes time and money. You can definitely do a soil test and add lime now (to unfrozen soil), then add organic matter in spring.
University of Maryland Extension's Home and Garden Information Center offers free gardening and pest information. Call 800-342-2507 or send a question to the website at hgic.umd.edu.
Plant of the week
Lamb's ears 'Helene von Stein'
Stachys byzantine 'Helene von Stein'
Don't let the tender fuzzy leaves of lamb's ears fool you. This silvery groundcover, grown primarily for its foliage, stays attractive in summer and winter. The soft velvet-like texture begs to be petted, making it perfect for a children's garden as well as perennial bed or edging. "Helene von Stein" is one of the best cultivars, with larger leaves, a higher tolerance of heat and humidity, and a tendency not to flower, so no deadheading is required. (Standard varieties have 18- to 24-inch spires of small violet flowers in summer.) Stachys takes full sun or partial shade, and well-drained soil is essential. It is deer-resistant and drought-tolerant. Spring division every 2-3 years is suggested. — Debbie Ricigliano