Planting distances are very much a matter of choice - for bare roots, 3 plants per metre is adequate, 5 is good, 7 in a double staggered row will give a dense hedge quicker. Generally, smaller plants should be planted at higher density. Cell grown should be planted at 4 per metre in a single row or ideally 6 per metre in a staggered row.

For more information on planting distances please see our planting density advice section.

Viburnum opulus is one of a number of plants that produces flowers and berries on last year's stem growth. A healthy plant will produce new stem growth each year quite happily requiring little pruning and maintenance. Trimming however, is sometimes required to maintain or to improve the shape of your plant or hedge.

The ideal time to do this is after flowering in late spring. Ensure that any dead, diseased or broken branches. are removed as part of the process. In addition, to keep a good air circulation which helps to prevent disease, look for and trim out any overcrowded branches. Up to a third of the shrub can be trimmed out yearly if necessary without any negative impact.

Trimming flowering branches back at the tips will naturally impact on berry production that autumn, however the upside is that new growth will develop throughout the remainder of the year on which an abundance of flowers and berries will then be produced the following year.

For old, overgrown plants that have slowed in their flower production and have a leggy, woody appearance, regenerative pruning can be undertaken. This is where old wood is significantly cut back almost to the ground, with particular care taken to remove any weak or straggly branches. This allows the plant to re-establish itself with renewed vigor and growth in subsequent years to become a stunning specimen once again.

This type of hard pruning is best done later in the year but before winter so that some new growth can establish prior to the plant becoming dormant. This will ensure that it bounces back again the following spring.