SHEAR MADNESS

Recently, while attending the San Francisco Home and Garden Show, I talked with Plant Amnesty, a non-profit organization dedicated to promoting better pruning of plants. I found their information very useful, especially when it comes to the subject of topping trees. We agree that this procedure should rarely be done. Pruning should enhance a plant's natural beauty, to make it look tidier, cleaner, and less bulky. Shrubs should rarely be sheared, unless they are formal hedges or topiary. Here are some guidelines that they recommend:

Pruning Trees: Ornamental trees should never be topped. Selective thinning is all right to open up trees. But stripping off all of the side branches from a mature tree is harmful. Taking off crossing or weak branches, as well as a few of a tree's lower limbs, is okay. Trees may need to be "fixed" over three to five years, so that many severe cuts are not done all at once.

Priming Shrubs: Pruners should take a long, close look at the shrub and then "wander, ponder and prune", locating unwanted branches and imagining how it will grow in the future. Dead wood should be taken out first. Most pruning consists of thinning cuts, which force new growth in existing branches. A thinning cut removes the branch back to another branch or twig, or to the ground.

Pruning by Growth Habit: Prune to enhance the plant's natural shape or habit. Plants have one of three basic habits: cane growers; mounds; tree-likes.

Cane growers are plants that renew themselves by sending up new branches called canes from the base. Examples are Roses, Oregon Grape, Nandina, Hydrangea, Bamboo, Forsythia, Weigela. These are very tough plants, and can hardly be hurt. Take out 1/8 to 1/3 of the oldest, as well as some of the puniest canes down to the base to keep the size of the plant under control. Prune to open up the center. Tidy up the top with thinning cuts.

Mounds are medium-tough plants, often found in mass plantings. have small leaves and supple branches. Examples of mounds are Abelias, Escallonia, Choisya, Barberry, Raphiolepis, Holly, Oleander, wheeler's Dwarf Pittosporum.
These plants usually just need tidying or redudng in size. Locate the longest, most unruly branch. Grab the tip and follow the branch down to snip it off 2-12 "below the surface level of the shrub. Look for the next "too-long" branch and continue tidying all over the shrub, until it looks shorter but natural. Cut to a side branch or bud, if possible.
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Tree-likes are large shrubs which need thinning out with many small cuts. They usually have
stiff branches. They should not be heavily pruned. Never remove more than 1/8 of the total leaf surface in one year. Examples are Rhododendrons, Pieris, Magnolia, Camellias, Cotoneaster, Bottle Brush, Lilac, Tea Trees. Most tree-likes just need to have all of the dead wood taken out. Big crossing branches and suckers may also be removed. Take back or remove any branches handing on the ground or growing the wrong way into the interior of the shrub. Be very sparing and selective in your pruning. Too much pruning can stress these shrubs.

A few tough tree-likes, such as Photinia, Pyracantha, Privet, Laurel may be headed back or sheared into hedges with a heading cut that cuts off the tip or end of a branch. This heading creates bushiness, but is not good for most other shrubs and trees.

Pruning is much like giving a haircut It is easy to take it off, hard to put back on. Plant Amnesty recommends knowing when to quit. If a plant is really too big, you may want to move it, or remove it (go ahead, be ruthless). But try selective pruning first!