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Fruit

Here are the answers to some commonly asked gardening questions about fruit.

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When is the best time for pruning fruit trees; I have a pear, plum, cherries and apple, and they are very old and in very rough shape.

Plums, cherries and other stone fruit don't really like a lot of pruning - otherwise they become shy at fruiting and it can take a few years for them to get back into fruiting mode. I would try and limit yourself to removing dead, dying, diseased or damaged wood, branches that are too low or spread too far, those which cross from one side of the tree to the other and those that are touching or rubbing. Pruning of all stone fruit must be carried out any time from May to August.

Apples and pears can either be pruned in winter or in summer. Winter pruning encourages growth and summer pruning encourages flowers and fruit. But again try and limit how much you do - or do it over two or three years. I would start by removing the same sort of growth as outlined above and then leave it for a year and see what happens.

After pruning, give a feed with a balanced granular fertiliser.

Further details are available in my pruning book

I have a good crop of apples on my two trees this year, but many have developed a brown mark on the top. What is it and is it dangerous to eat the fruit?

The brown marks on your apples have been caused by a late spring frost damaging the developing fruits.

There is nothing you can do now, but don't worry the fruit is perfectly safe to eat.

What are the red growths on the foliage of my peach tree?

This is the disease peach leaf curl which is a very problematic disease. A plant that you know is susceptible should be sprayed in February with Bayer Dithane or a copper fungicide - such as Bordeaux Mixture - and again twice more at two week intervals.

Affected leaves should be removed and burnt. In the autumn gather up and destroy all the leaves and spray with Bordeaux/Dithane; spray the ground below the tree, too to kill spores there.

Protecting the tree from rain in spring will help prevent the disease as it stops the spores splashing back onto the leaves. If it is wall trained it is easy to make a tent over the plant using plastic sheeting right down to the ground. Obviously, if it is free standing this makes it more of a problem.

For the last two years my boysenberry has thrived producing plenty of new growth - it is located in my fruit cage, next to a loganberry which does very well. The mystery which I'm sure you could solve is: "Why does it not set any fruit even though it has masses of blossom?". Any advice you can give would be welcome.

Most boysenberry problems revolve around the fact that growers don't get any flowers - so at least you're more than half way to a good crop!

The boysenberry is an American hybrid and not so well suited to the British climate as, say, the loganberry.

If your plant flowers but doesn't set fruit then there are two possible causes. First, the flowers are being frosted or damaged by cold winds at or just after flowering or the flowers are not being pollinated by insects.

If the first is the cause, then a layer of horticultural fleece laid over the plant will keep off a few degrees of frost/cold wind. But this must be removed in the day to allow pollinating insects at the flowers.

I need help in how to prune a 100 year-old-vine, probably a 'Black Hamburg' growing under glass in NE Scotland. It fruits extremely well every other year apparently (100 pounds of fruit). We have just moved to the house and need advice, or can you recommend a website, or book.

Grape pruning can be complicated and not easy to explain over the internet.

There is a good book published by the RHS called The Fruit Garden Displayed which has a good section. Similarly the RHS Encyclopaedia of Practical Gardening - Fruit is good.
As is my own book on pruning!

In spring I planted up a strawberry planter with two different varieties (forget their names) with the view of getting an extended crop. We were advised by the garden centre where we bought the plants to remove all but one fruit from each plant in its first year to encourage root growth - this we did; removing lots of flowers and small fruits.

This year, the plants produced lots of foliage but virtually no fruit. Can you advise me how best to get these plants to fruit well next year please?

Strawberry plants - if grown well - usually come with the promise of flowers in their first year, the buds are often already formed, which is why yours had plenty in the first year. Encouraging flowers in the second year is often the tricky part.

If you get lots of foliage and little fruit it usually means that:

the plants are still getting established and should fruit the following year.

or they are being fed with two much nitrogen and not enough potash. Feed once a week in the growing season (March-September) with a high potash liquid fertiliser, such as a tomato food.

Should I remove this year's leaves from my strawberries?

I wouldn't remove the foliage now - it's a job that needs to be done immediately after fruiting. But I would tidy up the plants - removing dead, dying or diseased growth.

Where should I keep my strawberry planter over the winter - is it OK to keep it outdoors in a sheltered spot with a clear plastic bag over the top to protect against frost or should it go into a shed?

It's OK to leave the planter out all winter - just put it somewhere sheltered, close to a south-facing wall. But if you want to try and force an early crop you will need to keep the planter frost free.

I certainly would not cover it (or any other plants) with a plastic bag - this will give no protection and the sweaty conditions it creates will lead to all sorts of disease problems.

I planted some autumn raspberries last year and on a neighbour's instructions cut them down hard in the spring. This year I've done some more as the four berries I tasted were so delicious. They said they were ready to fruit and are about 45cm (18in) high so do I prune them in February like last year or not. Also do I prune the canes I put in first of all and if so when? I know I have to mulch them with muck - how about mushroom compost as its lighter to ferry down the garden?

With regards to the new canes - try half and half. It's possible that some of the 45cm (18in) high growth may produce a slightly earlier crop of raspberries.

Yes, you need to prune the current year's canes every February.

No, don't use mushroom compost. It contains 6% lime and raspberries prefer an acid soil - good old muck is much better.

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Garden answers

Fruit

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