We have two plum trees, a ‘Victoria’ and a ‘Czar’; they both blossom and usually produce a small crop, but a lot of the plums drop before they are fully formed. Is it because our soil is sandy?
Most sandy soils tend to be low in calcium, and in the absence of sufficient available calcium the trees will go through a difficult time when the stones are being formed. If there is not enough to go round, some of the plums will be shed. An application of garden lime over the whole area during the winter will probably solve your problem. In spring, mulching with well-rotted manure or compost will also help.
Can you tell us if our native Hertfordshire is a good county for plums; and if so, which would be two of the best dessert varieties for us to grow? Our garden has a south-facing wall about 9 m (30 ft) long.
Fortunately, plums can be grown almost anywhere in the country. Some of the top-class dessert varieties need a little extra protection, but your wall would help to supply the warmth that makes all the difference when plums are grown as trained trees. The two varieties I would recommend are ‘Kirke’s Blue’ and ‘Golden Transparent’.
Why do my plum trees have so many bare branches with leaves bunched together at the ends? After six years I am still waiting for the trees to crop.
You are evidently plagued by bullfinches. The damage is done early in the new year, when these birds attack any unopened buds they can reach safely, so it is only those at the end of the branches that are left to develop. The best answer would be a fruit cage covered with netting—but this is not practical with free-standing plum trees. You could try spraying with a bird repellent, but you will have to repeat the application after heavy rain.
Some five years ago we planted a ‘Merryweather Damson’ tree. It is now beginning to crop but the fruits are more like plums than damsons, with little or no damson flavour. Did we plant the wrong variety?
You did if you want damsons of the traditional flavour and colour. One of the best is ‘Shropshire Damson’. It makes a small tree, needs no routine pruning, is self-fertile, and in general is very well suited for garden planting.
Several years ago we planted a ‘Monarch’ plum tree. It has cropped well, but we are disappointed with the quality of the fruit. What we wanted was an early blue plum for stewing and for dessert. Can you recommend one? ‘Rivers’ Early Prolific’ would fit the bill; but it needs a pollinator, so I would advise you to keep your ‘Monarch’, which flowers at the same time. ‘River’s Early Prolific’ is a small blue plum which stews well as soon as it colours. When fully ripe it is sweet and full of superbly flavoured juice. It also freezes well.
Several of our plum trees have got out of hand, with lots of dead and crossing branches. When is the best time to wade in with a saw to tidy them up?
The dead branches can be removed at any time—the sooner the better. Early May is the safest time for taking out living wood, but be sure that all the cuts are cleanly made, as close to the trunk as possible, and that the wounds are immediately and carefully dressed with a proprietary wound sealant. 117
Being fond of greengages, we planted a ‘Jefferson Gage’ and an old-fashioned ‘Green Gage’, but neither of them has succeeded in producing more than a few fruits.
The old-fashioned ‘Green Gage’ is never a good cropper and it must have a pollinator along with it which flowers at the same time. ‘Jefferson Gage’ is a reliable cropper but it, too, needs pollination. Your problem is one of blossom timing: the ‘Jefferson Gage’ finishes before the ‘Green Gage’ starts. ‘Oullin’s Golden Gage’ blossoms as late as ‘Green Gage’, while ‘Coe’s Golden Drop’ flowers as early as ‘Jefferson Gage’.
Two years ago we planted a ‘Warwickshire Drooper Plum’ tree in our lawn, hoping it would be both ornamental and useful, but it does not seem at all happy.
All plum trees do better when planted in clean, cultivated ground. To help your tree to get going, make sure that it is allowed a circle about 2 m (6 ½ ft) in diameter completely free of grass and weeds. Your soil will probably be short of lime, so start with an application of garden lime and follow this up with Growmore fertiliser in February or early March, at a rate of 65-100 g/m2 (2-3 oz/sq yd).
One of our plum trees—a ‘Victoria’ which has done well for several years—is now looking sick. Several of the branches have leaves with a silvery sheen on them. What can we do to bring it back to health?
That silvery sheen is most likely a sign of silver leaf, a disease covered by an order which requires the removal and burning of all the dead and infected wood before the middle of July. No doubt there will be dead wood in your tree, so get it out as quickly as possible and burn it. If you do cut into living, healthy wood paint the wounds immediately with a proprietary wound sealant. To improve the health of the tree apply Growmore fertiliser in late February or early March.