Most of the trees grown in gardens have a rounded or broad-spreading shape, and even more so if the trees are isolated and have plenty of space to fill. Big, broad trees are beautiful in their own right, of course, but are even more attractive when teamed up with some trees of upright shape.

Trees of upright shape are often called pillar or pencil trees to denote the relative narrowness of their outline. They are also called fastigiate, which is the botanical term for trees of upright, narrow habit. There are very few trees of naturally upright habit, really just Italian cypress and some pillar junipers.

The Italian cypress is a striking part of many Italian and other Mediterranean landscapes, appearing on slopes and close to stone buildings. The reason that nature has not favoured the success of pillar trees is that they are no use as competition for ground space. Other trees could spring up close by and take up the space foregone.

The Italian cypress and some junipers do not suffer competition because they usually grow in rocky places where there are few, if any, competing trees.

However, nature continually throws up tree forms of fastigiate shape: oak, beech, birch, pear, hornbeam, cherry, poplar, yew and thuja, as well as the cypress and juniper mentioned. Ironically, the classical pillar tree, the Italian cypress, generally does not do so well in Irish gardens and would look a little out of place in a rural setting in any case.

Its best chance is near the coast, where the longer growing season seems to help it.

Juniper grows well here and there are various kinds, such as Hibernica, Sentinel and Blue Arrow, all of which are good for a smallish tree.

The thuya variety, Smaragd, forms a narrow pillar of bright green, great in winter.

The fastigiate oak, Koster, has become very popular in recent years, being planted a lot in towns where space is tight, but it can be used in a country garden to create contrast of shape with broad trees.

The columnar beech variety, Dawyck, has been popular for many years (shown in the photograph), forming a tight pillar up to 10 metres and more. There is a purple-leaved form too.

The upright birch, Betula pendula (Fastigiata) is not as popular, as it seems like a contradiction of a semi-weeping tree. However, the upright form of hornbeam, Carpinus betulus (Fastigiata), is an excellent tree, upright and narrow when young, broadening somewhat and becoming more conical as it grows.

The Lombardy poplar is well-known, an upright variety of the black poplar, and widely planted. The pillar cherry, also called Lombardy poplar cherry, Prunus (Amanogawa) is still planted for its narrow shape and in a warm garden it can look very well.

The columnar yew, also called Irish yew, was discovered as a wild seedling in the 18th century in Fermanagh and has been planted in graveyards ever since. There are also yellow-leaved forms. Used a lot as a street tree in towns, the pear, Pyrus (Chanticleer), is of upright habit, but is not much used in gardens, though it could be for its spring blossom and late leaf colour.

To achieve the benefit of the contrast of shape of an upright tree, try to plant where it will be seen against a backdrop of ordinary broad trees or a building.

While these trees can be planted in a group and can look well as a small group of three or five, they usually look best as a single tree, like an exclamation point.

Move the young tree into position and see how it looks, shifting it until it looks right. Even a metre or two can make a big difference.

Usually one or two is enough and too many columns in a garden can look spiky and over-done. Planting is the same as any other tree and now is a good time.

Butternut squash

Butternut squash is a relatively new vegetable in Irish gardens and on shop shelves. It is related to marrows, courgettes and pumpkins, and like pumpkins can be stored for winter use.

However, it lasts better in storage than pumpkins and it is a more convenient size than pumpkins, which can often be too big for easy use.

It can be used for soups and roasted. It performed very well this year because the summer was so good, but usually it does better in the extra heat of a polythene tunnel or a greenhouse. It needs to be taken indoors before frost, which can severely damage it.

Flowers

Spring bulbs should be in the ground by now, but should be planted if not. Tulips and alliums tolerate late planting. Bedding plants for spring colour should be put in now, if not already done. Lift dahlias, begonias and gladioli from frosty localities to prevent damage, or cover them with soil in milder areas.

Trees, shrubs and roses

Planting of bare-root deciduous trees, hedging and shrubs can continue during dry weather. Do not plant into wet, sticky ground or into planting holes that fill with water, because the wet conditions cause the roots to rot. All kinds of pot-grown trees and shrubs can also be planted. Roses can be pruned.

Fruit, veg and herbs

Store root vegetables that have not already been harvested. Plant new fruit trees and bushes. Dig over vegetable ground, removing old crops. Control weeds over areas of ground that will be dug over later. Spread compost before digging in, but only dig ground for vegetables when the soil is dry and not sticky.

Lawn

Lawn mosskiller can still be used if moss looks like it might be a problem. Lawn moss will grow strongly until early May and can build up to damaging levels. Occasional mowing in winter is a good idea if the soil is not too wet. Grass tends to grow a little over winter and an occasional mowing, when dry, will keep it right.

Greenhouse and house plants

All tender plants should be taken indoors now. Set up a greenhouse frost protection heater for tender plants such as geraniums or fuchsias. Remove all debris and dead plants, and ventilate occasionally to dry the air. Water very little to reduce the risk of grey mould disease.