Q • I have a vigorous old privet hedge that has become too overgrown in recent years. I would like to cut it way back and start anew. My questions are, can this be done and if so, when is the best time?

An overgrown privet hedge can be rejuvenated by cutting it back severely to about 6 inches from the soil line. This should only be done while the hedge is dormant in winter and should be completed before new growth begins again in spring.

Fertilize after pruning, applying 10-10-10 or similar formulation of granular fertilizer at the rate of 2 to 4 pounds per 100 linear feet of hedge row. Split the application by applying one half of this amount to each side of the hedge, lightly scratch into the soil surface and water it in well. Finish off with 2 to 3 inches of organic mulch at the base of the hedge that extends out over the root zone several feet on either side. Water as needed in the absence of adequate rainfall.

Regrowth will be quite dense and may need to be thinned somewhat over the summer months. To create a formal look, shape the outline of the hedge by shearing, tapering the sides so the base is slightly wider than the top. This opens all levels to more sunlight and will reduce shading of the lower stems, which invariably leads to the loss of lower leaves.

Write to Chip Tynan at chip.tynan@mobot.org or Horticultural Answer Service, Department PD, P.O. Box 299, St. Louis, Mo. 63166. Check his blog at: mobot.org/gardeninghelp/hilight.asp