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By Dennis Bishop and Dennis Bishop,Special to the Sun | August 24, 2003
A local garden center recently recommended that I spray aphids with horticultural oil rather than an insecticide. I thought that horticultural oil was only for fruit trees and was only sprayed in the dormant season. Is that true? What was once called dormant oil spray is now generally referred to as horticultural oil. Dormant oil was primarily used during late winter and early spring to control insect pests before they became active. It is still used for that purpose; however, it can be sprayed in all seasons as long as the temperature is above 40 degrees and below 90 degrees.
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FEATURES
By Ellen Nibali and For The Baltimore Sun | September 24, 2014
According to the frost/freeze chart on the Home and Garden Information Center website, I'm thinking that if I cover my tomatoes with row cover or something during light freezes, I can have sun-ripened tomatoes into November. Will this work? Fortunately, tomatoes do not need to ripen on the vine to have good flavor. At the end of the growing season, tomato plants fade as days shorten, sunlight weakens and temperatures drop. But long before a hard frost hits, the tomato fruits start exhibiting poor flavor and texture, plus uneven ripening or blotches.
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FEATURES
July 19, 1998
Q. There are little bits of white fluff growing all over two of my yew shrubs. I don't see anything moving around on the foliage. What should I do?A.You're describing the white, waxy egg sacs of cottony camellia scale. The immature versions (known as crawlers) of this insect pest are feeding on the leaf undersides. They are not a serious pest, but their feeding may lead to an accumulation of excreted plant sap below the feeding sites. A black fungus, known as sooty mold, may then grow on the honeydew, detracting from the shrub's appearance.
FEATURES
By Ellen Nibali and David Clement and Ellen Nibali and David Clement,Special to the Sun | August 18, 2007
My outdoor Hibiscus moscheutos is being eaten up. I love the plant and hate to see it this way. Is there is something I can do? Larvae of the hibiscus sawfly are difficult to detect, because they are the same color as leaves and feed underneath. They may have finished feeding by now, but if you still find them in numbers, you can spray with insecticidal soap, horticultural oil or Spinosad. Be sure to spray when it's below 85 degrees and use a summer dilution rate for soap or oil. Or knock the larvae off into a bucket of soapy water.
FEATURES
By Ellen Nibali and David Clement and Ellen Nibali and David Clement,Special to the Sun | August 18, 2007
My outdoor Hibiscus moscheutos is being eaten up. I love the plant and hate to see it this way. Is there is something I can do? Larvae of the hibiscus sawfly are difficult to detect, because they are the same color as leaves and feed underneath. They may have finished feeding by now, but if you still find them in numbers, you can spray with insecticidal soap, horticultural oil or Spinosad. Be sure to spray when it's below 85 degrees and use a summer dilution rate for soap or oil. Or knock the larvae off into a bucket of soapy water.
NEWS
June 6, 1999
Q. There are lots of yucky white growths on the bottom of my holly leaves and all over my yews. I've never seen them before. Are my plants in trouble?A. Cottony camelia scale attacks holly, yews, camelia, euonymous, hydrangea and other landscape plants. The white waxy growths are egg sacs produced by the female scales. The crawlers that are emerging will suck the juices from plant foliage.No action is necessary if you're seeing a light infestation. But if your plants are covered with these sacs, you could apply insecticidal soap or horticultural oil, which will kill the crawlers on contact.
FEATURES
By Ellen Nibali and For The Baltimore Sun | September 24, 2014
According to the frost/freeze chart on the Home and Garden Information Center website, I'm thinking that if I cover my tomatoes with row cover or something during light freezes, I can have sun-ripened tomatoes into November. Will this work? Fortunately, tomatoes do not need to ripen on the vine to have good flavor. At the end of the growing season, tomato plants fade as days shorten, sunlight weakens and temperatures drop. But long before a hard frost hits, the tomato fruits start exhibiting poor flavor and texture, plus uneven ripening or blotches.
NEWS
July 18, 1999
Q. My sister and I just finished building a beautiful pond in her back yard. The problem is, the water in the pond has turned a disgusting green. I can't even see the fish swimming and I'm afraid the algae will kill the plants I bought to put in the pond. What should I do? A. Algae growth is rapid during warm weather, especially when there are no plants to cover the water surface. Put your plants in as soon as possible; the algae will not harm them. You'll notice the water becoming clearer within a few weeks.
NEWS
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)
FEATURES
By Baltimore Sun reporter | January 14, 2010
Question: When I brought my dwarf citrus trees indoors for the winter, the leaf color changed. Now they are spotty and have little red dots, plus something like spider webs. How can I treat the problem? Answer: Citrus trees are highly susceptible to mites. The first control tactic is to give them a good hard shower in a bathtub or other suitable place to dislodge the mites. You can also spray your trees with horticultural oil or insecticidal soap. Read the label and dilute the product appropriately for indoor plants.
NEWS
By Dennis Bishop and Dennis Bishop,Special to the Sun | August 24, 2003
A local garden center recently recommended that I spray aphids with horticultural oil rather than an insecticide. I thought that horticultural oil was only for fruit trees and was only sprayed in the dormant season. Is that true? What was once called dormant oil spray is now generally referred to as horticultural oil. Dormant oil was primarily used during late winter and early spring to control insect pests before they became active. It is still used for that purpose; however, it can be sprayed in all seasons as long as the temperature is above 40 degrees and below 90 degrees.
NEWS
July 18, 1999
Q. My sister and I just finished building a beautiful pond in her back yard. The problem is, the water in the pond has turned a disgusting green. I can't even see the fish swimming and I'm afraid the algae will kill the plants I bought to put in the pond. What should I do? A. Algae growth is rapid during warm weather, especially when there are no plants to cover the water surface. Put your plants in as soon as possible; the algae will not harm them. You'll notice the water becoming clearer within a few weeks.
NEWS
June 6, 1999
Q. There are lots of yucky white growths on the bottom of my holly leaves and all over my yews. I've never seen them before. Are my plants in trouble?A. Cottony camelia scale attacks holly, yews, camelia, euonymous, hydrangea and other landscape plants. The white waxy growths are egg sacs produced by the female scales. The crawlers that are emerging will suck the juices from plant foliage.No action is necessary if you're seeing a light infestation. But if your plants are covered with these sacs, you could apply insecticidal soap or horticultural oil, which will kill the crawlers on contact.
NEWS
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)
FEATURES
July 19, 1998
Q. There are little bits of white fluff growing all over two of my yew shrubs. I don't see anything moving around on the foliage. What should I do?A.You're describing the white, waxy egg sacs of cottony camellia scale. The immature versions (known as crawlers) of this insect pest are feeding on the leaf undersides. They are not a serious pest, but their feeding may lead to an accumulation of excreted plant sap below the feeding sites. A black fungus, known as sooty mold, may then grow on the honeydew, detracting from the shrub's appearance.
NEWS
March 11, 2001
Q. How do you get rid of fire blight in sweet cherry trees? At least that's what I think is wrong. Last summer, some of my young shoots wilted and died and one branch died back. I want to prevent the problem this coming season. A. Cherry trees don't get fire blight. You may have a couple of different problems. Oriental fruit moth larvae may have entered the young shoots, causing wilting and death. Or the shoots may have been damaged by very cold temperatures. The branch dieback was probably caused by a canker disease.
FEATURES
July 12, 1998
Q. I think the Eastern tent caterpillar has returned to my yard. I'm seeing the gauzy-looking nests at the ends of my willow and locust branches. I plan to kill them with diazinon. If I can't reach them all, will they be worse next year?A. The pest you describe is the fall webworm, not the Eastern tent caterpillar. The webworm, a type of caterpillar, feeds inside silken webs on terminal growth and causes only minor damage.Put away the diazinon, because it will kill the many different predators and parasites that control this pest.
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