Answer: The most common causes of browning needles and dropping needles are 1.) Lack of moisture in the ground at anytime will cause them to yellow and brown,
especially if they?re dry going into the winter or summer. If the soil is dry going into the winter or summer, the needles lose moisture, can?t replace it and bingo, you have dead needles. You?ll see this browning happening on the sides exposed to high winds, sun, or facing the foundation of the home, where it usually stays drier.
2.) Spider mites, sucking insects, can be a problem on Alberta spruce, especially the cool season mites. Cool season mites are active in the cooler seasons, namely spring and late summer / early fall. And that is the time to check for mites. By the time you see browning due to mites, most of the damage has already taken place. To check for mites, take a piece of white paper and hold it under a branch. Shake the branch on the paper. Look on the paper for very tiny slow moving specks. If you can?t
see any, try gently wiping your hand across the paper looking for a slight smear. Both are indication of mites, and these mites will cause the needles to turn brown and fall off. You can spray for mites using insecticidal soaps or horticultural oils, but here?s my way of taking care of the mite problems without the chemical sprays, and keeping good moisture in the soil. Beginning in mid to late March, start a regiment of hosing out the spruce with a strong stream of water about every 2-3 weeks. And I mean really hose it out. This not only waters your spruce regularly, but
also dislodges the mites and blows them off the plant! Do this right up until the first of July. In July and August, hose it out maybe once per month, but when September arrives, go back to the hosing out every 2-3 weeks. Again, knocks off the cool season mites, and waters the spruce. Keep this up through October, and then water as needed to make sure it has good soil moisture going into the winter.
This procedure is one of the best ways to keep your Alberta spruce looking good every year, with just a garden hose, and a good stream of water.
So, check the soil moisture and check for mites. Correcting these problems will help your spruce regain its health.
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