Spring has sprung and growth has well and truly begun. Now is a good time to prune broad-leafed evergreen shrubs to improve their density, to restore, rejuvenate and reshape, or just to give them a bit of a tidy up. Most evergreens can be pruned at any time from now until mid-September but to get the best response, especially when a hard, restorative prune is required, a spring prune gives the best results.
A common misconception is that evergreens don’t drop their leaves but of course they do, just not all at once. They shed the oldest foliage throughout the year to varying degrees, but most evergreens drop the greatest amount in spring and early summer coinciding with the new season’s vigorous flush of growth. If left unchecked some species can quickly become leggy after their spring leaf drop, especially those such as Photinia which tend to produce the new growth at the shoot tips and shedding what’s below or behind, so a spring prune can be used to force them to reshoot lower down and thicken up again.
To avoid damage, don’t prune evergreens during a cold snap, and of course another complicating factor regarding pruning at this time of year is that of nesting birds; not only would it be ethically and environmentally undesirable to disturb nesting birds but it is also illegal. Therefore, you should always check for nesting activity first before pruning dense evergreens and delay if necessary, until August if you have to.
Many of the more vigorous evergreen species such as laurel and Photinia are also quite hungry plants which can often be a little starved for nutrients at this time of year, especially in their first couple of years after planting. A balanced feed such as Fish, Blood & Bone applied twice per year, once in March or April and then again in mid-June, will help to keep them growing well and to quickly reshoot after pruning. If however there are key signs of nutrient deficiency, such as yellowing of the foliage, then a bigger “boost” in spring may be required by applying a suitable high-nitrogen fertiliser, and perhaps followed by an application of Epsom Salts for a jolt of Magnesium, to restore a lustrous green.