NATIONAL Trust gardeners at Peckover House made the most of snow outdoors to crack on with one of their 'indoor' jobs – washing the 300-year-old orange tress. The gardeners clean the orange trees with a soap solution to control insect pests and rid the tr

NATIONAL Trust gardeners at Peckover House made the most of snow outdoors to crack on with one of their 'indoor' jobs - washing the 300-year-old orange tress.

The gardeners clean the orange trees with a soap solution to control insect pests and rid the trees of unsightly mould that forms on both the oranges and leaves.

It is a task carried out on a yearly basis and is a more environmentally-friendly alternative to insecticide - but is a time consuming job.

Janet Crockford, a part-time seasonal gardener at the house in North Brink, Wisbech, has been helping with the task in hand.

She said: "The age of these trees implies that they have been well cared for over the years.

"It's important that we destroy the scale insects and mealy bugs, which feed on the sap. It's these pests that secrete honeydew, which falls on the leaves below, forming a sooty mould.

"Not only do these black deposits look unsightly, if infestation gets out of hand it can cause leaf drop."

Janet, who works for nine months of the year in the gardens at Peckover, spends the summer months putting in the same time and effort as a volunteer.

Over the last few days she has cleaned everything from the leaves to the branches of the trees, which stand more than 3.5m tall.

The trees are situated in the Orangery, towards the rear of the Victorian garden at Peckover House, but surprisingly little is known about them.

The only written history originates from F J Gardiner's 1898 book The History of Wisbech, in which he states that the tree bearing sweet oranges in Lord Peckover's garden was purchased at the "famous sale at Hagbeach Hall" and was already at least 200 years old.

This could indeed be the case because Citrus sinensis (the Chinese or Sweet orange) was brought to the Mediterranean from the Far East by sailors at some point in the medieval period.

It was used extensively in Italian, French and Dutch gardens by the late 1600s and this fashion extended to Britain where the ability to grow them in pots and move them to a protective buildings during the winter made their cultivation feasible.

These trees will soon be looking their best, not just because of their annual clean, but from February onwards is when orange blossom starts to make an appearance.

Sweet oranges are not only productive plants but highly decorative ones too, with dark green and glossy evergreen leaves. They also have a magnificent perfume which originates from the white flowers that appear from late winter to early spring.

Advice on growing your own oranges from Head Gardener, Allison Napier:

• Choose a specimen which has been grafted (a seed raised plant will take many years to reach flowering size).

• Grow in a neutral to slightly acidic compost.

• Place it in a pot which will allow you to put the plant outside in the summer but bring it into a frost free (5C) area during winter.

• Water when the surface of the compost has dried out - do not over water. However too little water can turn the leaves yellow.

• Feed with a purpose made citrus feed (there are summer and winter feeds available).

• Look out for those pests which make a beeline for citrus plants - scale insects and mealy bugs - and wipe them off before they become a serious problem.

• If you need to prune to restrict its size, do it in late winter and avoid removing flowering stems.