Autumn/Winter Pruning, Visual Interest, Maintenance of Flower Borders
“Think natural sculptures and winter interest before you start”.
For some, an immaculately tidy garden is priority above anything else, but in winter and autumn do consider which structures can be left for winter interest and homes for wildlife. Remove anything showing sign of decay or fungal infection and burn rather than compost, especially when signs of rust or leafspots.
Hydrangeas are pruned the following year after the first frost has gone to protect the plant. This leaves changing winter colour on the flower head, but also these mopheads of flower that look great frozen in time when the weather is cold.
One of my other favourites is Eryngiums (sea holly) with their very architectural spiny foliage below the flower head.
Hylotelephium (previously Sedum) have strong umbellifer flower structures which can look good right into Spring.
Late flowering Clematis (group 2) can be tidied up but should not really be pruned until late February at the earliest, or early Spring. Remove all dead or weak stems before new growth begins, checking individual stems from the top downwards until you reach a pair of healthy buds. Prune just above these removing the spindly or damaged growth above. Avoid heavy pruning or flowers will be lost.
Group 3 Clematis such as “jackmanii” should be pruned in February in Southern areas and in early March towards the North. This process is almost opposite of pruning Group 2 plants. Instead of starting at the top of each growth and working down, you start at ground level and work up until you reach the first pair of good, strong buds; then you prune just above these.
From a design point of view, consider a simple metal frame so borders and flowers are the star. Alternatively go full-on design and have painted obelisks in wood creating architectural structure throughout a border all year round. One important note is to prune a young Clematis (first year’s growth) hard to stimulate growth.
Create “free plants” e.g. Hosta’s and Salvias by lifting and dividing. Perennials (plants that come back yearly) especially those clump-forming in a border, can be divided when growth slows down. I find October is best to do this, this helps to keep the plant healthy and produce stronger growth. The best way to do this is with two forks pointing in opposite directions put down the middle of the perennial and forced apart to avoid root damage. Now you have “free plants”!!