In the Garden June 19, 2009

• If you are in a relatively frost free area, you may be enjoying the cheerful flowers and fragrance of luculias. The winter flowering varieties are gratissima and pinceana whereas it is grandiflora which flowers in summer. These plants can get a bit scruffy and leggy and the time to cut them back hard is straight after flowering. Most forms will root easily from cuttings as long as you use the fresh new growth as soon as it has firmed up and is not floppy or brittle. Luculias only come in pink or white.
• Deciduous plants are given their most severe prune when dormant in winter. This is because their energy has been stored in their root systems over winter so it is less of a shock to them if you cut the top back hard. So June and July are the time to get out pruning – fruit trees (but not cherries or plums which are summer pruned), grape vines, raspberries, kiwi fruit, roses, wisterias, deciduous trees and shrubs (but not flowering cherries, either). Head out with the ladder and the loppers, the secateurs and the snips.
• We don’t use pruning paste to seal cuts, even after major tree surgery, but we do try and make sure that cuts are clean and not hacked and jagged. In plants as in humans, clean cuts heal faster. You can buy pruning paste and use it if it makes you happier.
• Regrettably one size does not fit all when it comes to pruning and it helps to have a little bit of knowledge at least. We can’t compress all of it down to two simple rules or one sentence but we will try and demystify it as we go.
• Pruning ornamental trees is for shaping purposes. Keep most trees to a single trunk, avoiding forks for the first few metres. These are weak points where the tree can split apart. A balanced shape is more pleasing to look at than a lop-sided tree which can end up pulling the tree over. It is much easier to trim a small tree around two metres tall than to work on a misshapen tree of five, ten or fifteen metres tall so start young when you can do it with the secateurs and not the chainsaw.
• Rose pruning can continue through until August.
• Wisterias need regular, if not constant pruning. However, as they flower on last year’s growth, you can not cut them off at ground level and expect them to flower in spring. Find the main branches to give some structure and shape, and trim all side growths back to three or four leaf buds from the main branches. Borer can be a problem so check for tell tale holes and dead branches and cut these out. You can spray cooking oil or use any light oil down the borer hole if it is in the main stem and you don’t want to cut it out. There is nothing shy and delicate about a wisteria but you do want it to flower.
• The rule of thumb for pruning grapevines and kiwifruit is the same as wisterias though grapes you are pruning the side growths back to one or two buds whereas kiwifruit you count out to about the eighth bud before cutting off the rest of the vine. Apples are done the same as wisterias.
• From the school of random pieces of curious information: Chinese wisterias flower on bare wood and naturally twine anti-clockwise. Japanese wisterias flower a little later with their leaves, have longer racemes of flowers to compensate and twine clockwise.