Looking for alternative plants to box? Here are the top five choices from our Wisley trial
The spread of box blight and box tree caterpillar has focussed attention on finding evergreen plants for topiary and formal plantings, and RHS Garden Wisley has been trialling suitable alternatives.The trial, in the Walled Garden, has involved clipping different plants to demonstrate the variety of different form, colour and texture available.
Here are their top five suggestions to use as alternatives to box:
You could use any common yew. This one is a low, spreading form ideal for small hedges and topiary. Yew clips to a dense, smooth surface like box. Unlike many conifers it will also recover (slowly) from hard, renovation pruning.
This cultivar has 3cm (11/4in) long leaves, but others are available with much smaller ones. This has been very vigorous so far, so may need regular attention to contain its size. It clips well with shears.
With leaves that are a very similar size to box, this cultivar is supposed to have a bushy, compact habit but we’ve found it to be rather lax and trailing so far. It should clip well to give a dense finish but can be vigorous in favourable conditions so, again, it may need regular clipping.
This cultivar is tolerant of pretty much any soil other than waterlogged and doesn’t mind a little shade, so it should be very reliable. The leaves are box-sized and the shoots thin so should clip well. It produced lovely orange flowers this summer, but we’ll be clipping it regularly next year so it probably won’t get a chance to flower again.
We have no experience with this plant but research suggests it can be clipped into a hedge. It is worth a try for the beautiful foliage: narrow, 3cm-long (11/4in) leaves with amazing green/purple/brown/grey colouring. Corokias are from New Zealand and should be hardy. They’ve established well here although we haven’t tried clipping them yet.