Crawling pests attack Norway spruce trees


April 18, 1999

Q. I have a row of eight Norway spruce trees. The four that are closest to the street have been slowly dying over the past five years. Needles yellow and drop and branches dry up and die. There are very small brown structures that look like unopened buds on most of the branches where the needles join the branches. Is this my problem? What can I do?

A. It sounds as if you have located the culprit, spruce bud scale. This is a serious pest of spruce that can eventually kill large trees. It is encouraged by drought conditions, so it makes sense that your most stressed trees (those near the hot pavement) were the first to succumb.

Spray your trees thoroughly in late June when the scale crawlers are feeding. Use an insecticidal soap or horticultural oil (2 percent rate). Pick a sunny, dry day to spray, with temperatures under 90 degrees.

You may also want to spray with oil at the dormant rate next fall. Keep monitoring your trees each spring for signs of the crawlers and spray if you see them.

Q. I have some older trees in my yard that have light-green blotches at different places on the trunk and largest branches. The trees look healthy but I'm concerned they may be diseased.

A. Not to worry; those blotches are lichens. Lichens are living organisms -- a symbiosis between algae and fungi. They are entirely harmless to your tree bark and do not signify any problems or potential problems for your trees.

Q. I love spinach but can't grow it because it starts to bolt quickly in the spring where I live in Anne Arundel County. Are there some other mild greens that will last into the summer?

A. You might want to try beet greens; they're very similar to spinach in taste and texture. Sow seeds every two weeks through the end of June. Your best bet is to grow lots of Swiss chard. This vigorous plant makes large, mild-tasting leaves all summer long.

'Perpetual Spinach' and 'McGreggor's Favorite' are two other types of beets grown for their tops. They also will grow through the summer.

As for spinach, you can sow it in late summer and fall.


1. Start cucumber, muskmelon, watermelon and squash seeds indoors to have plants ready for outdoor transplanting by mid-May.

2. Fertilize spring-flowering bulbs with a balanced fertilizer or "bulb food." The result will be good foliar growth that will provide the food reserves for next year's flowers.

Garden tips are provided by the Home and Garden Information Center of the Cooperative Extension Service 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

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