Action plan: Nigel Colborn’s essential jobs for your garden this week
- Nigel Colborn shares his advice for protecting peach trees from fungal disease
- British gardening expert recommends fixing a plastic cover over the branches
- He also explains the importance of keeping gardening records for the future
PROTECT YOUR PEACH TREES
Peach leaf curl is a debilitating fungal disease that affects peaches, nectarines and a few other stone fruit.
The fungus, also known as Taphrina deformans, can attack ornamental trees such as the Japanese apricot, Prunus mume, too.
Symptoms begin to show as blisters on new foliage, often escalating into a hideous bloating of the leaves. This is extremely damaging, particularly to young trees. As well as reducing yields or destroying an entire year’s crop, it can affect the tree’s growth.
By the time your tree shows symptoms, it is too late to control the disease. The spores will have rested in the leaf buds where they become active and invade the baby leaves as they expand in the spring.
Spring blooms: Cover peach trees until May to control disease
There are no effective fungicides. But you can control this disease by protecting the tree from rain. Do that by fixing a clear plastic cover over the branches and stems as soon as the leaves have dropped. Leave it in place until May.
Remember to leave open access at the sides of the cover for pollinating insects to gain entry in spring.
Design for a simple shelter can be found on the RHS website at rhs.org.uk.
SECURE A TIDY CROP
Apples and pears will be dormant now so if you still have winter pruning to carry out, try to finish that before the sap begins to rise. Winter pruning is done mainly to preserve the shape of your tree. On youngish trees, aim for an open, gobletshaped canopy with a hollow centre. You can also prune old fruiting spurs. Those are short, twiggy side-shoots which produce clusters of fruit. Thin out the twigs on each, leaving just two or three dormant buds.
GET YOUR HOUSE IN ORDER
January can be a difficult month for greenhouse health. Nights are still long, humidity is always high and fungal diseases are a constant risk.
Botrytis can spread rapidly among young plants, rotting leaves or stems. To control botrytis, keep your greenhouse scrupulously clean, with surfaces as dry as possible. On sunny days open a vent or two to let in clean air.
Water potted plants only when their compost is beginning to dry out and do that in the morning.
Nigel chose Mahonia x media ‘Winter Sun’ (pictured) as this week’s plant, revealing it thrives best in sun or part shade
TIMELY TIP
If you spend a lot of time in your garden, a diary can provide valuable information for future years. Records of sowing dates, variety names, yields and a few other details in simple, terse sentences, are fine. If you’re a habitual diarist, you probably include much gardening detail already.
But that isn’t necessary for everyone. I used to use a hard-cover notebook, but now, it’s far less of a chore to keep the diary on the computer. Even so, I enjoy reading some of the pre-electronic entries, written with a fountain pen, in my spidery scrawl.
PLANT OF THE WEEK: MAHONIA X MEDIA ‘WINTER SUN’
Mahonias are curious shrubs originating from Asia and the Americas. Most have prickly leaves and grow as suckering or thicket-forming shrubs. For fragrance, the best is M. japonica, but for all-round garden value the hybrid Winter Sun is better. Winter Sun (right) is a cross which inherits sweet fragrance from M. japonica, but has the more upright habit of M. lomariifolia and flowers a little more generously. It’s excellent as a stand-alone feature plant or for incorporating into shrubbery. The flowers are clear yellow, rather than primrose, but still have the gentle fragrance akin to lily of the valley.
Any free draining soil is suitable and flowering is always better in sun or part shade.