Gardening: Tree of life

Thuja has remarkable qualities to prevent rotting. Its timber is called western red cedar and it is used to make high-quality wooden greenhouses.

As the name suggests, the wood is a rusty-brown colour when freshly cut and it later changes to a silvery grey as the outer fibres of the wood are bleached by the action of sunlight – but this only affects the surface.

Cladding

An application of oil restores the colour, but this has to be repeated. The wood is so durable and rot-proof that it is sometimes used as a cladding material for buildings, even in this damp climate.

This timber is a soft wood and it is so soft that a thumbnail can mark it easily. It is not structurally strong and it has been used as cladding and fence posts in its native territory of North America.

This species is Thuja plicata, which is a big forest tree to well over 20m and too big for garden use. But there are some versions that are used in gardens, notably Atrovirens, which has been used as a hedge, much like the ubiquitous Leyland cypress.

It has the advantage of re-sprouting, like yew, when cut back, which Leyland cypress cannot do. It has attractive green foliage that emits a fruity, resinous scent when crushed and also during warm weather.

The scent is reputed to deter midges, but only in calm weather when the volatile oil is not blown away.

The oil of arborvitae has long been used in herbal medicine for a range of ailments, including cold sores, respiratory problems, scurvy, warts and cancer. But thuja oil can be poisonous if used in excess.

Brightening up winter

There is also a yellow-leaved form called Aurea, which can be used to brighten a garden in winter.

Stoneham Gold forms a golden cone shape when the new yellow shoots appear in spring and then become green in summer.

The white cedar, Thuja occidentalis, comes from eastern North America and is grown in gardens in various decorative forms.

The most widely grown of these is Rheingold, which forms a small tree of conical shape, its foliage in a soft, old-gold colour that deepens in winter and has a hint of pink in the emerging new leaves.

It has an attractive looseness of the foliage.

Smaragd

The next best variety derived from the white cedar is Smaragd, Danish for emerald, which is also used as a name.

This is a very fine garden tree, making about five metres tall and one metre wide at the base of a tapering column after 25 years.

It is one of the best pillar-like trees and can be lightly trimmed to make it even more narrow. Filiformis makes a mound of whipcord-like drooping growth.

Apart from the North American species, there are some kinds from Asia. Formerly known as Thuja orientalis, this is now platycladus, and there is one very popular kind called Semperaurea.

This forms a rounded egg shape to more than one metre tall and half that in width. Its winter colour is good and it has distinctive pleated sprays of foliage.

Apart from Atrovirens, which is generally only grown as a hedge, the others are ideal as specimens, used to inject a touch of colour into a border in winter.

Each one is best given its own space and not crammed in with other dwarf or small conifers, when they tend to detract from one another.

All kinds are easy to grow in any ordinary, good fertile soil, as long as the ground is not very wet and waterlogged in winter.

Bullfinches usually begin to feed on flower buds in late winter or very early spring, as the buds begin to swell.

Bullfinches usually begin to feed on flower buds in late winter or very early spring, as the buds begin to swell.

They feed on the swollen buds by using their curved beaks to peck out the centre of the bud. Bullfinches like to eat fruit tree buds, principally apple, pear, blackcurrant and cherry trees, including decorative cherries grown for their flowers.

While a flowering tree is not much affected by the loss of a few buds, the damage on a fruit tree can be very extensive, practically halting cropping.

The only sure way to stop bullfinches is to cast a net over the trees, but this can be difficult.

Flashing CDs and ribbon tapes can be used as an alternative, but these need to be changed around from time to time as this intelligent bird soon gets used to them.

Flowers

Some kinds of bedding plants – begonias, geraniums and busy lizzies – can be sown soon in a heated propagator. Outdoors, herbaceous perennials can be lifted, divided and re-planted during good weather. Check on stored dahlias or gladioli that they have not dried out.

Trees, shrubs and roses

The planting of all kinds of trees, shrubs and roses, especially bare-root or root-balled kinds, can go ahead during dry weather, not during wet or frosty weather. Prune roses now to get early flowers. Check that staked young trees are properly tied because they can be rocked by strong winds.

Fruit, vegetables and herbs

Dig or rotavate over vegetable ground, removing old crops not already taken out. Control weeds over areas of ground that will be dug over later. Plant new fruit trees and bushes, and control weeds around established fruit trees and bushes. Prune fruit trees and bushes now.

Lawn

Lawns can be mown now if there is a spell of dry weather and the ground is firm to walk on. One mowing this month will leave the grass neat until March. Moss-killer can be used now, if not applied in autumn. Lawn edges can be re-cut now, so that the soil is moist and easily cut.

Greenhouse and house plants

Keep the greenhouse dry by watering only as much as required. Any grape vine should be pruned now and then can be given more water towards the end of the month to encourage early growth. Check all plants for infestations of pests such as greenflies, red spider mites or white flies.

Read more

Winter pruning

Outstanding displays of winter berries