The Island Garden

2005-09-22 / News

By Roger Marshall

In my early morning forays for coffee at the corner deli I have

been accosted by several people with gardening questions.

“How should my hedge be pruned?” “Why doesn’t my hedge grow out at the bottom?” “Can I prune rhododendrons now?”

So I thought I’d devote this space to some information about pruning.

But, don’t go out and start on your hedge now. September is a little too late to cut because the new growth will not have time to harden, and it will get killed by frost in mid to late October. Next spring a hedge pruned now will have to put out new growth which will weaken it. If we have another drought next summer, a weak hedge might not survive.

An example of a hedge not properly trimmed. An example of a hedge not properly trimmed. Having said that, take a look at the picture of the first hedge. Notice how it is cut flat on top and the top has grown very wide. The width of this growth has cut down on the light that can reach the lower parts of the hedge, so no growth has taken place lower down. Consequently, the hedge is all top with big gaps in the lower areas, gaps which are large enough for animals to easily walk through. The only way to get this hedge to grow thicker at the bottom is to prune the top way back to allow light to get lower down.

The best solution is to cut the hedge to the ground and as it grows cut it with a taper making the top much thinner than the bottom. Ideally, the top of a privet hedge should be about 70 to 90 percent of the width of the bottom. The second picture shows how a hedge, cut with a slight taper has grown thick and strong all the way to the ground. This type of hedge cutting provides a pretty good barrier to animals, although I have seen deer simply run right through it.

This is what a properly pruned hedge should look like This is what a properly pruned hedge should look like The next question pertains to rhododendron bushes. “When can they be pruned?” The answer is simple, they can be pruned anytime, but — and it’s a big but — if you prune them now you’ll lose next years flowers. As the picture shows, the flowers are contained in the middle of a leaf spray. If you prune that off, the plant simply does not have enough time to grow new flowers before next spring.

The best time to prune rhododendrons is immediately after they’ve bloomed and the flowers have dropped off. That happens in mid-spring. If you prune the plant back then, next season the shrub has all summer to make new flowers, and you won’t miss a years worth of growth.

“What about pruning raspberries and fruit trees?” Don’t worry about either right now. Wait until mid-winter when you want to get outdoors and enjoy the crisp cold air. Prune out all the dark brown/gray stems from your raspberry patch, and then cut the remaining stalks to about 4 feet high. The plant will send out smaller side shoots at the tip, which will increase the number of raspberries to harvest during the summer.

Similarly, fruit trees can be left until after the leaves have dropped off, although I like to prune out water shoots all summer. After leaves have dropped and the tree has gone dormant, cut out water shoots. These are the straight shoots that grow up the middle of the tree. Prune away any crossing branches that may rub together. Where the branches rub exposes the branch to disease.

And finally, prune the tree for shape. Never take more than onequarter of the tree off at any time. If you are restoring a tree do it over two or three seasons. Chop the prunings and use them for kindling. Apple and cherry have a nice aroma when burned.

So there you have it. Prune at certain times of the year to suit the shrub or tree. Don’t try and prune everything now.

If you have a gardening question send it to the Jamestown Press, and we’ll try to answer it.

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