Cultivation
Most viburnums are hardy, tolerant shrubs that are easy to grow on most soils. The majority thrive on clay and alkaline soils, but there are exceptions, such as Viburnum furcatum, which requires acid conditions. As with all long-term garden subjects, thorough ground preparation, including the incorporation of good garden compost or well-rotted manure prior to planting, aids establishment and the development of a healthy root system.
Most viburnums will be planted as three-litre, containergrown plants, although you may find larger specimens of the most popular forms, such as Viburnum plicatum f. tomentosum ‘Mariesii’. These are usually a good investment as they bring maturity to new planting schemes and gain a year or two in growing time.
Watering the plant in the growing pot prior to planting and thorough watering after planting are essential, regardless of the time of year or the amount of natural rainfall.
Most viburnums require little in the way of pruning, except to remove dead and damaged wood. Many just need room to grow. Hard pruning after flowering will prevent the formation of fruit and may limit autumn leaf colour, which is better on mature foliage. As a rule, selective winter pruning of deciduous plants is best. Evergreens should be pruned lightly in spring, if necessary.
Several viburnums, including Viburnum lantana and Viburnum opulus ‘Compactum’, are excellent for rural settings and country garden schemes. They mix well with cultivars of Sambucus, Crataegus and Cornus as well as popular deciduous shrubs, such as Philadelphus and Deutzia. The latter have the benefit of summer flowers, usually after the viburnums, but they lack autumn colour and fruit, which the viburnums can supply.
Viburnum davidii works well under the dappled shade of deciduous trees with other evergreens, such as Choisya, Sarcococca and Euonymus. The blue-black berries on the female form of the viburnum are a long-lasting seasonal highlight.
Those viburnums that need space, such as Viburnum plicatum f. tomentosum ‘Mariesii’, make good planting partners for trees, especially birches. The horizontal branches and defined lines of the viburnum complement the slender stems and light branches of the birch, and the flower colour also highlights with the bark of the trees. ‘Cascade’ would be a good alternative for fruit rather than autumn foliage colour.
The British native, Viburnum lantana, is good with the double form of wild cherry, Prunus avium ‘Plena’, in a rural setting. Both have lovely autumn colour and both like chalk and clay soils.
Because there is such diversity within the genus, there is a viburnum to suit nearly every shrub-based planting scheme. The autumn colour of the foliage or the fruits may not be the main reason for planting, but it is a bonus and worth considering at the time of selection.