Aiming a blowtorch at pests can result in damage to tree


April 15, 2001

Q. Last year I finally learned that the large nests that appear in my crabapple trees each year are not from gypsy moths -- they are Eastern tent caterpillars. My neighbor burns them out of his trees with a blowtorch. He offered to do the same for my trees. Is that safe for the tree?

A. You should politely decline his offer. The blowtorch could easily damage the bark and vital plant tissues, leading to dieback and pest problems. You can use a garden hose or broom to dislodge the nests and drop them into a bucket of soapy water. You can also kill the caterpillars when they are small by spraying the microbial insecticide B.t. on the foliage.

Q. Is it a good idea to use those soluble plant foods in the spring on flowers and vegetables? Is it better to use the liquid seaweed or fish emulsion? Should you spray these fertilizers on the leaves or apply them to the soil?

A. Yes, it's a good idea because nutrients in the soil are not readily available in early spring, and plant roots are not sufficiently developed to pick them up. Some "starter" fertilizers have a higher percentage of phosphorus to promote root growth, but any of the balanced soluble fertilizers (they contain nitrogen, phosphorus and potassium) will work fine.

Liquid seaweed and fish emulsion are good organic alternatives. Seaweed products sprayed on plants confer some frost resistance to tender plants. Always read and follow label directions. Plants do take in nutrients more efficiently through leaf surfaces (especially the undersides) than through roots. But it's easier to apply liquid fertilizers to the soil, and it's less likely to burn plants. And try to add 1 inch of compost to your garden beds in the fall or early spring to ensure a steady supply of nutrients to your plants through the growing season.


1. Fertilize spring flowering bulbs to produce good foliar growth, which provides the food reserves for next year's flowers.

2. Presprout bean and corn seeds before planting them in the garden. Place the seeds between moist paper towels, roll up the towels and keep them in a ventilated plastic bag on top of your refrigerator.

3. Spray grapevines susceptible to black rot with a protectant fungicide before and after the bloom period.

Backyard Q&A is by Jon Traunfeld, regional specialist for the Home and Garden Information Center, Maryland Cooperative Extension Services of the University of Maryland. For additional information on these questions, or if you have questions of your own, call the center's hot line at 800-342-2507, or visit its Web site at / users / hgic.

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