What are the cone-like growths that appear on some spruce trees during mid-summer?
Although they look vaguely like cones, the strange growths you notice on the spruce trees are probably Cooley spruce galls produced by aphid like insects called adelgids. The insect requires two hosts (Douglas fir and spruce) to complete its life cycle. During spring when the insect is developing and feeding on the spruce, the galls begin as a slight swelling at the base of needles and are not as noticeable. By mid-July, as the adult insects emerge and migrate to the Douglas fir to complete the life cycle, the galls dry out and start to take on the brownish color of cones. Although the galls affect the look of the tree they do very little harm. Q: What are Cold Hardiness Zones? Which zone applies to Fort Collins? A: The USDA Cold Hardiness Zone Map delineates the average minimum low temperature for all regions of the US. Most of Fort Collins falls into zone 5 where the minimum temperature range is from -20 to -10 degrees (Fahrenheit). Although temperature tolerance is only one measure
