I've put it off far too long. I'm going to do it. I think. If I can bear it.

I have two very old bridal wreath spireas in my front yard, probably not as old as my home, which is 98, but darned near. The base of each shrub shows signs of having been cut to within four feet of the ground at least twice, judging from old, nearly petrified wood left around the base.

The best time for pruning a spring-flowering bush is right after it finishes blooming. This way, you can be assured of flowering the following spring. The same holds true of forsythia, lilac, weigela, etc.

Bridal wreath spireas are old-fashioned, spring-flowering beauties that respond beautifully to major surgery as well as judicious pruning. They are vigorous growers to have such dainty flowers.

Earlier this summer, I thinned canes on a row of newer bridal wreath spireas - about 11 years old - to encourage healthy growth. Cane pruning is cutting back the oldest branches and dead, diseased or unruly ones close to the ground. This opens the shrub to light and better air circulation. Thinning cuts on healthy branches help maintain the size and shape of the bush by cutting back to outward-facing lateral buds.

Again, work is done after it flowers in spring.

My older spireas have needed more drastic measures by cutting back to about 3 to 4 feet above the soil line. I'm not worried about blooms. It will take several years for the shrub to return to vigor. I cut back the first bush three years ago and fresh, young stems have grown nicely with that wonderful arched form, but at a more manageable size. Most bridal wreath spireas grow from new shoots or canes at the base.

This pruning method - called "rejuvenation" - is good for cane-growing, overmature plants, like my ancient bridal wreaths. The second bush grew to a huge size this year and bloomed, but it's all top growth. Underneath a layer of foliage is spindly, bare stems and branches of various sizes and dead spots, which tend to happen with bridal wreaths. It's quite large, at least 6 feet tall, and wider than the span of my open arms. Actually, it's a nice screen (I can feel a rationalization coming on … ). OK, I admit I'm tempted to leave it until spring because cardinals make their nests deep inside it. Unfortunately, rain keeps splitting it apart and the branches aren't springing back. If we have any heavy snow or ice this winter, it will be completely flattened.

If I can't bring myself to hack it completely back, I may use a technique called renovation pruning. Essentially, this is removing 1/3 of the plant each year for three years, resulting in a renewed shrub. You can use the same technique on an old lilac, for example.

Here's how it works:

1. Remove dead, spindly or diseased branches.

2. Study the shrub. You don't want to start indiscriminately removing branches or you could wind up with an ugly, weirdly shaped bush. Figure out which old branches to remove. Then tie a piece of twine or string around the ones you plan to lop off to prevent mistakes.

3. Using bypass loppers or a small pruning saw, cut each branch as close to the ground or base of the plant as possible. As you remove each branch, step back and look at the shrub. Then remove the next branch. Repeat until you've cut out 1/3 of the oldest growth. You may need to do a little shaping, too, so the bush appears balanced.

4. Repeat this process for the next two years. At the end of the third year, you'll have a renovated shrub.