May - pruning special !

Pruning

In the past month I have a lot of questions about pruning - so here is a simplified summary for the nervous beginner and the not-so-sure keen gardener.

Why?
We prune to keep the plant healthy, to give it a good shape and to produce good flowers and fruits. Plants that get too dense will not allow enough air and light to filter through and so will become less productive. Plants that get too straggly will begin to look unsightly and become less vigorous.

Sometimes you need to be cruel to be kind.

What ?
A good rule is to follow the three D's.

Aim to cut branches and stems that are

• Dead
• Diseased
• Damaged

By doing this we reduce the chance of pests and diseases taking hold and from "die-back" happening. (Sounds nasty doesn't it but it is just when stems start dying back to the main stems or a major node). Cut to just above a bud or stem.

When?

There are different seasons for different plants but these are helpful rules-of-thumb;

Trees; prune in winter when they are dormant and least likely to be receptive to disease. 

Cut back to the main stem or trunk but avoid tearing the bark down the tree and avoid cutting too close the main stem or trunk. Do this by doing a main cut first further up the branch then a more controlled one without the whole weight of the branch bearing down.

Shrubs;  The biggest tip is; always prune after flowering and prune hard ( almost to the ground ) if it has stiff, straight, woody stems. 

1. Woody deciduous plants; those that have a woody exterior and often a foam-like looking centre with a small central hole such as Buddleja and Spirea. 

     These are to be pruned after they have flowered either 100-150mm above ground level (or in Forsythia's case, back to the main trunk) to allow a full year's growth that will flower the following year.

These are easily confused with those shrubs that need a second years growth before they flower on those stems. These just need THINNING - cutting back only the stems that have flowered that year just after these stems have flowered ( e.g. Philadelphus, Ribes).

If you are confused DON'T WORRY! Stay calm and carry and look it up on in a book. It's hard to kill these guys.

Basically if you cut both the above back hard because they have become disorderly you will get vigorous growth the next year; if it flowers the following year it is the former category. If it needs another year - it is the latter. You will certainly get all the benefit of the winter coloured stems on the Cornus if you do this.

If the plant doesn't come back at all..............well, sorry,...........it was time for the great compost heap in the sky anyway.

    2.  Woody evergreen shrubs; those that have woody stems but are evergreen such as many Viburnums, Laurels, Bay and Mahonia, Lilac.

Prune these to the shape you want them but just after they have flowered; that way you will get the benefit of the flowers that year and probably the next one too. Be careful not to cut back too much or you may expose the leafless stems and branches. Larger leaved plants ( such as Laurel) are best pruned with secateurs to avoid cutting the leaves in half which then die back.

    3.  Soft stemmed evergreen shrubs such as Fatsia, Choisya, Daphne and Pieris.

Prune to shape the shrub.Care is needed in this category as these plants are often more sensitive to frosts. Their fleshy stems are more prone to pick up pests and diseases so in many ways if you can avoid pruning them - please do! Certainly Daphne is a tender lady who needs care and protection. Avoid pruning all of these when frost is around so late spring is safest. 

Roses......I will cover another time! Hedges...........as above! Herbaceous plants.......you've guessed it.

As a final thought I leave you with the true story of the two beds of roses owned by the RHS. One was carefully cut to the letter of the law. The other was flail-mown by a tractor.

I will give you one guess as to which bed flowered best............................!