Aphids and fruit drop
Q Our apple tree has been beset with problems this year. Any advice? BRENDA MORTON, EVESHAM, WORCESTERSHIRE
A The initial leaf curling (inset) was caused by aphids. Although they distort the leaves, they rarely cause serious damage and natural predators usually eat them. Cutting off any damaged growth tidies up the tree and encourages new growth.
The white ‘fluff’ is woolly aphid, which can be difficult to control but brushing them off can help. Again, it may be necessary to prune off badly affected areas where they’ve caused swelling and distortion of the stems.
The extreme heat and drought earlier in summer probably caused the fruit drop, so it would be sensible to shorten the shoots produced this year, by about half or more (right), to encourage lots of new growth.
Q Can you help with cucumber problems? JOHN FITZPATRICK; DEE WATT, BY EMAIL
A John’s wilting greenhouse cucumbers (right), could be caused by a fungal disease. If they recover overnight but start wilting during the day it shows the roots can take up water but the fungus prevents it passing up the stem. Next year, grow in pots or growing bags so they’re in sterile compost, and keep them more shaded.
Dee’s poor fruiting is caused by whitefly sucking the sap then dropping honeydew onto lower leaves, which becomes colonised by black, sooty mould. Clean the greenhouse well this winter to stop them overwintering and clear away any weeds. Next year, keep plants strong and healthy, giving them light shade, high humidity and lots of feed. Once they start to produce a fruit or two, the subsequent fruits won’t set or develop if they’re short of feed. As soon as you pick the larger fruits, more will set.
Q Is my currant dieseased? PAM CULLUM, BY EMAIL
A This is brown rot, most likely to occur on large, overcrowded plants. It’s caused by damage to the berries as birds or insects feast on them, and spreads rapidly between berries that touch already-affected fruit.
Once the berries have been picked, cut out the older, fruited stems to thin the foliage and encourage air circulation. This should stop the problem next year.
Q Why are grapes shrivelling on one side of my grapevine? BOB, BY EMAIL
A Dying leaves and shrivelling grapes sounds as though one of the main stems is damaged. I suggest you reduce the growth on this side and look to see if the stem is constricted or damaged. You may then need to prune out the whole stem when you do your winter prune.