ONE of the most frequently asked questions at this time of year is "how do I stop my outdoor pots from drying out?" There are many angles from which you can tackle this problem.

Before you even put plant and pot together, try to choose something which doesn't need copious amounts of watering, such as marginal or bog plants. You're just asking for trouble and extra work. Anything Mediterranean, such as lavender or rosemary, will do fine.

Next, choose a pot that is big enough to hold the plant and a good inch of water between the soil and the rim. If possible go for one that has a glaze on the outside. Terracotta pots, although stunning and rustic to look at, are porous and allow water to drain or evaporate at a tremendous rate. If you go for terracotta ones, you can line the insides with polythene, or place plastic pots inside. Make sure that they are frost proof, as many cheaper ones crack over winter.

The right compost can help. Anything containing peat tends to dry out very quickly and can sometimes be awkward to water properly. It forms a crust and makes the water run off over the sides of the pot. Anyway, unless you are using peat from a sustainable source, it's not a very environmentally sound practice. A general all-purpose compost will do the trick, especially if you mix it with a good handful of water-retaining crystals. These swell up to ten times in size when water is added (a good party trick) and release it back slowly as the plant needs it.

Once the plant has been potted, you can add a layer of mulch to the top of the soil. This slows down evaporation, retaining moisture in the soil for longer. The mulch can be anything from woodchip, to crushed glass to sand or pebbles. It really depends on how much you want to pay, or what materials you have available. Crushed egg shells look different and will also keep slugs at bay.

Water the pots in the morning and evening. Watering in the heat of the day is often a waste of energy and resources because moisture almost instantly evaporates if the sun is hot enough. Droplets left on leaves can magnify the sun's rays and cause burns on the plant.

If you plan to be away for a week or two during the summer, you can set up drip feed, automatic watering and capillary matting systems with some success. However, it may advertise the fact that you are away and that the house is empty. The best bet is to ask a friend or neighbour to do any watering for you. It gives them an opportunity to have a nose round your garden, and for you to show off your prize pots.

LETTER OF THE WEEK

MRS Edgerley of Darlington has written in asking how best to care for an Aloe Vera (barbadensis) plant that she brought back from the Canary Isles.

The Aloe is a genus of plants with succulent foliage. This particular variety is a clump forming perennial. It has rosettes of long, thick, greeny-grey leaves with spines along the outsides. It will grow up to two feet (60cm) given the correct conditions, and will have tall stems bearing spikes of yellow flowers in the summer.

They are frost tender to only ten degrees C (50F). This means that they cannot really be kept outside, except perhaps for periods in the height of summer. They prefer to be inside (conservatory or well lit room) in full sun in a soil that is free draining.

A shallow pot with a good mix of compost and gravel usually provides the best habitat for them. The plants are sterile, which means that you can't grow them from any seed that may be produced from the flowers. Not to worry though, as they throw off plenty of off-shoots (clones) that can be separated and potted.

Water sparingly, but don't forget them. Usually once a fortnight will be sufficient during the summer. In the winter months restrain yourself to a maximum of one dose a month. I know it's hard not to water as you feel as though you are depriving the plant, but most house plants are killed through kindness rather than neglect. The first signs of over-watering is floppy, pale yellow leaves. Under-watering produces dry, brown leaves.

JOBS TO DO THIS WEEK

Deadhead the rhododendrons

As the flowers fade on the rhododendron bushes, you tend to be left with a soggy, brown mess where the brilliant display used to be. You can carefully pick off the spent flowers, but be careful not to damage the delicate buds just behind them as these will form the growth for the next year's flowers.

Plant out the dahlias

Any dahlia tubers or cuttings that have been growing in your greenhouse can at last be transplanted outside. It is wise to harden them off for a week or so before plunging them straight into the ground. This means sitting them outside during the day and either taking them back inside at night or covering them up with a light fleece. They need plenty of moisture to feed their fleshy leaves whilst they are growing, so throw heaps of compost into the bottom of the planting hole.

Provide easy access to water

Think about placing water tubs where you are most likely to need them. If you can try and catch run-off from the house or shed roof from existing drainpipes. If not, put the tubs where you want them and make sure that the hosepipe can reach it if you need to top it up. Keep the lids secure so that midges can't get in and breed.

Feed your acid-loving plants

Give all your acid-loving plants a boost with a sequestered-iron feed. Many of them have put on a good flower display over the last few months and need a boost. You can also put a layer of ericaceous compost around the base of the plants.

* Don't forget to tune into Brigid each Sunday morning on Radio Cleveland between 11am and midday.

Published: 08/06/2002