Late August or early September is the time I start thinking about cutting yew hedges. Any hard pruning should be done in March/April time but a general haircut is best carried out at the end of summer early autumn. For the not so formal hedges this might well be all they need in any year. For topiary type hedging you’ll need a few more trim ups to keep looking sharp.
If your hedge is getting a bit too wide then cut back in the spring when they can be pruned surprisingly hard and make a full recovery. If you are going to do a major prune then keep it to just one side at a time to cause as little stress to the plant overall. The cuttings are very toxic so make sure to wear gloves and clear up immediately if you have animals in the vicinity. Although yews are poisonous the clippings are actually used in the treatment of cancer. If you have a serious amount of yew hedging it might be worth contacting the Doncaster-based company Friendship Estates, who have been collecting yew clippings for the pharmaceutical industry since 1992, to see if the clippings are of any use.
By September your lavender flowers should have turned from purple to a dull grey signifying that it’s time for a trim. Lavenders like to be pruned twice a year, once in spring when the new growth starts, and again when it’s finished flowering. The problem is how far to cut back. lavenders trimmed too lightly will turn woody and straggly whereas too hard and it’s curtains, they won’t re-grow. Cut off the flower stems and between one third and a half of the new growth but do not cut into wood without leaves as this will not recover. It’s best to cut off less rather than more in the autumn and leave cutting back a bit harder for the spring. Either way leave the leafless wood well alone.
