Oystershell scale attacks cotoneaster, dogwood, lilac, ash, and poplar trees, including aspen and cottonwood. The best control is to apply dormant oil in late winter before bud break. The new “summer oil” sprays can also control the scale during the crawler stage (mid-May to mid-June).

Peonies make great cut flowers. Pick early in the day when the buds begin to show color and feel like firm marshmallows. Cut stems at an angle and place in cool water. Trim the stems and change the water daily.

Many classic varieties of herbaceous peonies like Sarah Bernhardt, Karl Rosenfeld and Festiva Maxima are not the best garden plants. They have huge double flowers on weak stems that collapse in first high wind or rain. A single form like Krinkled White or Sea Shell or a semi-double like Cherry Ruffles or Miss America are 30-36” tall with strong stems and look more in proportion in smaller yards.

Grape hyacinths reproduce by offsets – small bulbs at the base of the mother bulb. Late spring is the best time to divide, when they are nearly dormant but still have foliage. Dig up a clump and gently shake off the soil. Sprinkle bulb fertilizer into the bottom of the new hole and cover that with a little soil or compost. Space out the bulbs and replant at the same depth that they were growing before. Cover with soil and water in immediately.

The authors have received training through Colorado State University Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

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This page updated:  August 5, 2008