Tony Dickerson problem solves
Q Our allotment site is moving. How can we move our fruit crops? Ruth Dowse , Cheltenham, Gloucestershire
A Established fruit trees would be quite difficult to move and it’s usually not worth the effort, but soft fruit gives you a number of options. Firstly, I wouldn’t bother moving very old stock. Soft fruit eventually gets infected. You can’t test for virus but you should discard any plants with poor growth or where the foliage is stunted, streaked or shows a mosaic pattern, as these are all signs of infection. Older raspberries and strawberries are probably infected and are better replaced with some of the really good modern varieties available to try. Fruit bushes less than four years old are small enough to transplant when the leaves fall in late autumn. Lift with as much root as possible, but neatly trim any larger roots that break on lifting. Bushes, such as gooseberries and currants, that are six to 10 years old, are probably too big to move but once the leaves fall, take hardwood cuttings of healthy growth about 25cm (9in) long from this summer. Push a spade into full depth and wiggle it backwards and forwards to create a narrow trench. Fill it with sharp sand and push your cuttings two-thirds of the way down, spacing them every 30cm (1ft) in rows 60cm (2ft) apart. They’ll root well in the coming year for transplanting the following autumn. Cane fruit, such as blackberry, and hybrid berries, such as tayberries, can be treated in the same way.
As you’ve got a few months to go until the move, the other option with cane fruit is to layer new, unfruited shoots from this year. Peg them into well-dug ground and they’ll root very easily over the next few months. Alternatively, bend the tips of the new canes over and plant them in holes 30cm (1ft) deep. They’ll root readily and you can sever them from the parent plant when you’re ready to move in winter. As fruit is in the ground for many years, make sure your new allotment site is entirely weed-free before planting up. If this isn’t possible heel any transplants in temporarily when you make the move. You then have until about late February to get the permanent site cleared.
Q Can you identify these two ‘triffids’ that have appeared in my garden? Olga Davies-May, Albrighton, Wolverhampton
A The white-flowered plant is Datura stramonium, known as thorn apple due to its prickly seed pods. It’s related to both potatoes and tomatoes but, in common with most members of the Solanaceae family, all parts are poisonous. Given another couple of weeks or so you’d have recognised the other interloper in flower as Helianthus annuus, the common sunflower. Although quite unrelated, these two plants have one thing in common: seed of each was
Q What has happened to my begonia? Mr F Righton, Ludgershall, Wiltshire
A This is a condition known as phyllody, where flowers are replaced by leaves. It’s usually caused by virus or probably part of a birdseed mix. These are produced overseas in China and South America. The sunflower is an obvious constituent for bird-seed, but I suspect the thorn apple is a contaminant in the mix. Q Why, despite lots of precautions, do my carrots still have root fly damage?
Arthur Braybrooke, by email
A The carrot fly is a small, black-bodied fly whose larvae tunnel into the roots of carrots and, occasionally, related plants such as parsnips. There they create rusty-brown areas of damage, making the carrots inedible or allowing infection phytoplasma infections. Phytoplasmas are like primitive bacteria. Botanically speaking, flowers are just specialised leaves and it appears that these infections disrupt the normal genetic development of the flower, leaving it appearing as a collection of leaves. The infections are spread by small, sap-sucking insects, known as by secondary rots. Covering carrots with an insect-proof netting, such as Enviromesh, or placing a 60cm (2ft) high barrier of clear polythene around the rows to exclude the low-flying female flies usually gives good protection. Two thoughts spring to mind as to why you’re still seeing damage. You need to be vigilant and ensure there are no gaps in the covers. And secondly, if you’re using the same raised beds for carrots each year, the pest may be overwintering as pupae in the soil and then emerging inside your protective ring. Avoid this by rotating carrots around different raised beds, or by applying a biological control nematode in spring or summer, available from Dragonfli Ltd (tel: 01284 830400). leafhoppers. It would be wise to destroy the infected plant.
Other causes of phyllody include insect damage to shoot tips. Hot weather or water stress can also cause an imbalance in plant hormones resulting in phyllody. In most cases plants resume normal flowering when growing conditions improve.
Q Why haven’t the berries of our newlyplanted pyracanthas coloured up? Sue Pride, Preston, Hull
A Your new shrubs don’t have much of a root system and I suspect they may have become a bit dry at the roots at a critical time. If the berries shrivel and turn black remove them. Next year, in dry spells, put a couple of buckets of water on each shrub every week.
Q What can I plant on ground that’s infected with onion white rot? Julia Jones, Pwllheli, Gwynedd
A This is the most serious disease of the allium family, especially onions, garlic and leeks. It’s most evident from midsummer into autumn but the growth of the fungus is limited with temperatures above 20C (68F), so it’s more severe in cool, wet summers in the south. On lifting, the roots will have rotted, with white, fluffy fungal growth around the base of the bulb. There are no chemical controls. The disease can remain dormant in the ground in resting structures called sclerotia. It’s popularly thought that these can survive for eight years but it’s more likely to be twice that. Any veg that’s unrelated to onions will grow quite happily on infected ground. The real problem is to avoid spreading it around your plot on muddy boots or in soil attached to tools. Always wash footwear so you don’t take the disease home.