As the days become milder, everyone seems to be itching to get out into their gardens, and with loppers in hand, start to chop away at their shrubs. Friend Jessica moved into her new house (and garden) last summer and cannily noticed that flowering on her Philadelphus (Mock Orange) was rather meagre. She’s tempted ‘to hack it right down’ now. The question is, is this wise? I’d say Whoah! Hang on a minute. First things first: if you know what your plant is, then google ‘How and when to prune..a Philladelphus’ or look it up in a good gardening book before making the first cut.
The excellent RHS Pruning and Training book (sexy title, I know) really helps to de-mystify the whole pruning process and is a very practical guide to pruning trees, shrubs, roses and climbers. I find it invaluable, as pruning is such a vast topic and it’s great to have so many answers at your fingertips.
Jessica’s shrub certainly needs a fair bit of thinning-out, but Philadelphus, like quite a number of shrubs (and fruit bushes and canes by the way), flowers on the stems that it produced the previous year. If the whole plant is cut right back now, then there’ll be no flowers this year. What to do? As it’s still only February, I’d wait another month or so before doing anything. It may seem mild now, but the weather can still turn cold, and pruning will encourage new tender growth which could then be damaged by a late frost or, dare I say it, more snow! In March, dead, diseased and damaged stems can be removed, then the whole plant thinned out to leave the thinner, fresher looking stems that grew last year. These are the stems on which her flowers will be produced this summer. (More on this in March, accompanied with ‘how to’ pics.) If you have no idea what your plant is, then the rule of thumb is to let it flower before pruning. This will help you to identify the plant and, by knowing when it flowers, when is the best time to prune.
So the Philadelphus can wait (sorry Jessica), but here are some plants that do need to be pruned now:
- Autumn fruiting Raspberries, cut stems right down to the ground and fruit will form on the new stems that grow this year. Don’t be tempted to cut down summer fruiting raspberries now, as in common with the Philadelphus, you will see no fruit this year. If in doubt, don’t prune until plant has fruited. Or if you’re feeling experimental, then prune some of the canes now and leave the rest. This would probably be the option I would go for. (‘How to prune raspberries’ post following shortly.)
- Apple and Pear Trees, to reduce overcrowded ‘spurs’ on which the fruit is formed, and to keep tree airy so fruit has good chance of ripening. Don’t prune Cherry or Plum trees (or any other tree with stone fruits) yet as you will be leaving the tree vulnerable to getting Silver Leaf and cankers through the wounds. Established Plum or Cherry trees should be pruned in summer.
- Climbing Roses, to thin out and to train last year’s new growth to grow horizontally-this encourages more flowers and stops roses only forming at the top of the plant. (Another ‘How to prune a rose’ post following too.)
- Standard Roses, remove older wood to encourage younger, more vigorous stems and prune out any crossing stems which could rub against each other, causing damage which invites disease
- Hydrangeas, again to encourage new vigorous shoots and to keep a pleasingly shaped plant-prune just as the buds are forming-no later as Hydrangeas will bleed as they start to grow and pruning too late could kill the plant.
One last word of caution. Plants that have green-grey foliage, such as Lavender, or other Mediterranean plants such as Rosemary, are a little on the tender side, so don’t be in a rush to prune these plants just yet either. Judge the weather for yourself. If it’s continuing to be mild in March, then prune away. If, on the other hand, it’s still really cold, then hold off pruning until warmer weather is with us. When pruning Lavender, don’t be afraid to prune hard back to just above the lowest live bud. This may seem harsh as you may be removing a lot of the plant, but it will keep the plant in a much better, bushy shape than a lightly trimmed plant which will become ‘leggy’ in a couple of years time.
Most pruning won’t kill a plant, so do a bit of research, sharpen your secateurs and then have a go. You learn the most about pruning through hands-on experience!