Everywhere in the ornamental garden the signs of an impending spring are evident – snowdrops, crocus, mahonia, viburnum and hellebores are in flower, even the first grass cutting has been seen, and with shrubs showing young buds this is where there is work to be done.
Shrubs are beginning to stir after their winter rest and with this new-season growth comes the question of pruning. It seems to pose a problem for many people and at this t ime of the year it has to be done correctly. Cutting back some shrubs now can result in removing the colour they can provide for a whole season. It is an important job if you want to encourage plants to produce a good show and healthy new foliage.
A good rule is that shrubs that bloom before the longest day should be pruned immediately after flowering and those that flower later in the summer should be cut back now.
There are several which come into the latter category, these include buddleia, cornus, hypercium, lavender and certain varieties of spiraea.
Buddleia davidii, better known as the Butterfly Brush, requires hard pruning, not only to keep it in check but for better and bigger flowering. Cut it back to within two inches of the old wood. With our ‘mild’ winter this shrub is already showing rapid growth and yes it will flower if left untouched but will grow to an enormous size.
Cornus, also known as dogwood, is a shrub much prized for its leafless but highly colourful stems of red or yellow in winter, followed by a pleasing foliage all summer. C. alba gives red stems and C. stolonifera the yellow ones, but to get them, hard pruning is required now. Cut both down to a few inches from ground level.
Hypericum come in two popular varieties and one not so but still a valuable flowering shrub. H. calycinum, often called Rose of Sharon, is a great ground-cover plant which will grow in almost any position and any soil except waterlogged, in fact some gardenders find it invasive. Prune it hard now, whereas H. Hidcote, which grows up to six feet, is only cut back by a third. With H. inodorum Elstead there’s a bonus as its golden-yellow flowers are followed by egg-shaped ‘fruits’ which turn red in autumn.