By GEOFF MIERS
As we approach the depths of winter it’s necessary to sharpen the secateurs in readiness for pruning many plants in the garden to remove unwanted growth, to manage plant size and shape, remove pests and diseases, remove dead wood and to improve flowering and fruiting.
Generally follow a few simple rules and all will be good, remembering however that you can do more damage than good by pruning incorrectly or at the wrong time.
A classic example is pruning grapes. Some grapevines need to be cane pruned however if they are spur pruned you will remove most of next season’s crop. Whether to cane prune or spur prune or to combine both pruning methods for grape vines is the dilemma the home gardener faces. More on this later.
Pruning too early can also cause more harm than good. Roses along with frost damaged plants pruned too early for example can reshoot with this new growth being burnt off by the 20 to 25 frosts we average between now and the end of winter.
To date our coldest day this winter has been minus 2.2 degrees and subsequently tomatoes bushes, basil plants, pumpkins, zucchinis and even egg plants have collapsed because of this one night. In total we appear to have five frosts but many more could come, we need to be prepared.
Some plants like the Chinese and English mulberry, pomegranate and many of the deciduous fruiting and ornamental plants can be pruned now as pruning is unlikely to induce early budding.
If you are pruning off only dead wood this can be undertaken at any time as you will not be inducing new growth.
For frost damaged plants do not prune until mid to late July. After pruning as a general rule your plants will reshoot around six weeks later. Pruning in mid July your plants should be reshooting around the beginning of September when frosts become rare.
With deciduous plants, those that naturally lose their leaves over the winter months, the general rule is to wait until they have lost all their leaves and the sap has stopped flowing before bringing out the secateurs.
Grape vines, deciduous fruit trees, crepe myrtles, white cedars and other ornamental deciduous trees and shrubs are best pruned sometime between mid to late June to mid July.
With grape vines Italia and Autumn Royal need to be spur pruned while Muscat Gordo, Sultana, Carina, Crimson seedless and Menindee seedless all need to be cane pruned.
Put simply, spur pruning involves pruning back to two buds while cane pruning involves pruning back to eight to 12 buds. For more information consult with your local nursery for complete details.
With plants like grapes following pruning it can be good to give the vines a good clean up spray particularly if pests and disease has been a problem in the previous season. For example, powdery mildew was a big problem last season with so much rain.
Spraying grape vines after pruning and again at bud swell time with wettable sulphur will kill of most fungal spore and any microscopic mites. If scale and mealy bug have been a problem then consider spraying with white oil or any or the other oil and soap sprays.
Pruning deciduous fruit trees will increase fruit yield and quality and size of the fruit and this should be undertaken in the next month. Consult your gardening books, the internet or your local nursery as differing methods are required for different fruit trees.
With the Chinese mulberry it often drops its leafs and within one to two weeks reshoots. With these trees it’s best to prune immediately the foliage drops. With the English mulberry however you have many weeks to contemplate pruning as they have a much long dormancy period.
There are some plants that must be pruned to get best results and the crepe myrtle is a classic example as it only flowers to its peak if it is pruned hard annually. It will still flower without pruning however the results are disappointing.
Roses are another plant that should be pruned hard annually every winter and then should be pruned as required over the main growth period to ensure it blooms to maximum potential.
Roses are best pruned late June through to mid July. I prune roses generally around the July 20, give them a feed and a good clean up spray to remove any mite and fungal diseases. A hard prune over winter followed by a “clean up spray” and then given a feed should guarantee a magnificent display of blooms in early October.
Roses managed carefully through pruning and feeding will literally reward with blooms for eight months of the year.
Prune hard in June-July and then half hard in late January complimented by weekly dead-heading spent blooms should see your roses flowering for most of the year with the exception of June to August and January and February.
Many winter and spring flowering native plant species are best pruned after flowering. Many native plant species have nectar rich flowers that attract many birds that often bring with them a range of sticky pests and diseases including scale, mealy bug, mite and a range of fungal diseases.
Most major pest problems on native plant species are experienced after their flowering season. Prune after flowering and you can often remove the potential problem.
Citrus often benefit by some pruning however this pruning should be left until mid to late July.
When pruning citrus first remove dead wood, severely pest ridden or diseased wood, then trim the skirt to ensure fruit isn’t touching the ground and following this look to managing the general shape of the tree including reducing its height if its height is out of control.
With citrus it sometimes pays to thin out congested central growth to ensure good airflow and its absolutely necessary that any growth occurring below the graft needs to be removed.