Last week Dad railed against hedge clippers and the practice of pruning bushes within inches of their lives. Since the proper pruning of shrubs seems to be one of the most-asked questions we get, I'll keep going where he left off.

A recent series of lectures at Longwood gardens stressed the importance of knowing what your shrubs want to do and pruning to allow them to do it, rather than bending them to your will. That is a practice that will make neither of you happy. The wonderful thing about shrubs is that most deciduous shrubs, (the ones that loose their leaves), can be cut completely to the ground and will grow back from the roots. If you repent of over-clipping you can start with a clean slate. There is a forsythia in my yard that will get such treatment next spring. The picture at the top of this article is how forsythias are SUPPOSED to look.

As a rule of thumb, spring-blooming shrubs (like lilac, mock orange, weigelas, azaleas, etc) set their flower buds the previous summer. Looking at the lilacs and magnolias in my yard, I already see next spring's buds.

Many summer bloomers, on the other hand, set their flower buds in the spring on new growth. This is the case for butterfly bushes (Buddlejas), beauty berry (Callicarpa), Tamarix and Caryopteris. Of course there are always exceptions. Hydrangeas are a bit tricky as some bloom on new wood (the panicle type) and some bloom on old wood (the oakleaf type).

Once you know what time of year your shrubs bloom, you can plan your pruning schedule. Prune spring bloomers immediately after flowering, and summer bloomers in the late winter/early spring. Now what exactly to do? For the health of the plant, remove the oldest quarter (or third) of the stems from the base at ground level or an inch or two higher. This will do two things. It will open up the base and allow sunlight in which promotes branching and you will still have leaves on the bottom half of your shrubs. Secondly, it will keep the height under control.

Summer-blooming dieback shrubs like Tamarix, Buddlejas, and Callicarpa, can be cut to the ground completely once you start to see a hint of green in April. When I say cut to the ground, I mean it. They will put on 2-4 feet of new growth a year and will bloom profusely on this new wood. If you donıt cut them back, it's not a big deal, theyıll just be a little taller, mangier and less floriferous. We were a little busy this year and didn't get our Tamarix or butterfly bush cut back and the bloom is not nearly as spectacular as usual.

Finally remember this: July and August are the worst time to prune most flowering shrubs. The bushes think, "Oh, ok, I guess I better grow now" and put on new growth that won't have time to harden off before winter. And pruning spring bloomers now just removes the flower buds. Trimming-and I mean just trimming- evergreens to shape a hedge is allowable, but better done later in the fall. Stay inside in your air-conditioning, and leave the hedge clippers alone.