PRUNING 2 – WHEN TO PRUNE?

Posted on 31 Jan, 2008 3 comments

So having said how to prune, the next question of course is when to do it? Shrubs and climbers generally fall into one of two categories.

The first of these flower on old wood, that is, they make the wood one year and flower on it the next. My rule of thumb is that anything falling into this category flowers between January and June. So immediately after the flowers fade, they get my attention. This will include things like forsythia, flowering currants, weigela, philadelphus and the spring-flowering clematis.

The second type flower on new growth made in the current season; these flower between July and December. With these I wait until early spring before cutting back to avoid any die-back if we have a hard winter. The timing of this is much more dependant on the weather – a mild January such as we have just experienced started several of my clematis into early growth and I have cut back a few of them earlier than I would do in an average year. If we get a really cold spell in February, I may need to protect one or two of them with fleece but generally they will look after themselves. I usually reckon to start towards the end of February or early March, beginning with the hardier things and leaving some of the more tender stuff till late March or early April. There are a few exceptions; I like to prune my hibiscus with the leaves off (this only entails opening up the centre of the bush most years). Hardy fuchsias I leave until the new growth has just started to appear and then cut out all the wood from last year’s stems. Two of my shrubs don’t get cut back until May – the erythrina behaves like a fuchsia but only starts to start into new growth towards the end of April, and indigofera heterantha gets me worried every year by not showing green shoots until the second week of May (but then it’s in flower within the month so I have to be prompt with the cutting back).

Some clematis don’t really fall into either category – the ones with large flowers in early summer for example. For these, cut out any dead or weak growths in winter and shorten main stems back to the highest pair of strong buds in early spring.

At the end of the day, very few plants are killed by pruning in the wrong season. Most of the time, all you are going to do is lose one season’s flowers but I hope this blog helps prevent this mishap.

Comments

Spritzhenry

Thanks Andrew for the 2nd on-line tutorial! It's helpful and is just what Simon (tree surgeon) said. I have been very organised today. I made a table of all my Clematis plants, where they are in the garden, when they flower and their pruning groups: A, B, B/C and C. I am hoping that this will help in my pruning schedule, so I don't forget to do one of them at the right time. I think I shall also 'post' these on my GoY page, once I've recorded all the species.

31 Jan, 2008