Water wisely

Top 10 tips for successful watering this summer

'Plants in hanging baskets can be difficult to irrigate, so give yourself a head start by using the largest possible container.'

1 Rehydrate rootballs

1 Rootball soaking

To rehydrate pot plants with loam-free composts once they have dried out, plunge the rootball into a bucket of water with a few drops of washing-up liquid to act as a wetting agent. Wait until bubbles stop coming to the surface, and then remove from the water. A very weak solution of washing-up liquid used as the first watering after repotting will help with water retention.

2 Water-retaining granules

You can mix water-retaining granules into your growing medium, which will hold moisture for much longer periods. These granules absorb many times their own volume in water and gradually release it back into the compost for your plants to draw on. A self-mixed compost comprising peat-based multipurpose John Innes and water-retaining granules, gives a very good moisture-retentive combination. You can also now buy composts with the granules added.

3 Water into a saucer

Watering into a saucer reduces run-off. A saucer or tray of gravel is the easiest way to keep houseplant compost moist. Water into the saucer so the gravel becomes soaked, but the pot itself is not sitting in water. This acts as a reservoir and creates a damper atmosphere around the plant as some of the water evaporates. This method is ideal if you are not very good about watering your houseplants (at any time of year), as plants only take up water as and when they need it.

4 Go large with hanging baskets

5 Plastic mulch

Plants in hanging baskets can be difficult to irrigate, so give yourself a head start by using the largest possible container. It might not look much larger, but a 35cm (14in) basket holds 50% more soil and water than a 30cm (12in) one. In warm, windy weather you may still need to water twice a day.

5 The benefits of mulching

Many composts, especially the fibrous peat-free and peat-based types, will act like a wick and dry out quickly when they are exposed to hot, dry or windy conditions. Combat this by covering them with a mulch – the most effective type is plastic, but it is unsightly to look at. Have the best of both worlds by covering the compost with a polythene disk, to keep in the moisture, then disguise it with a layer of chippings or gravel. This will keep the polythene in place and reflect the sun's rays, keeping the root system cooler.

6 Micro-irrigation

For the busy gardener, micro-irrigation is the answer, although for many of us with water restrictions in place it won't be an immediate option. It can be set up to drip or sprinkle

5 Disguising plastic

water into pots and containers, or onto the border. A micro-irrigation system can also be fitted to a timing device, so that your garden is watered while you are off doing something else. Most systems are now available in kit form, with very clear instructions on how to install them. The other benefit is that you can start small, then keep adding to the system as you get more plants and pots, as the system is modular.

7 Targeted soaking

A simple way of getting water to new plants that are trying to establish in the garden is to scrape a saucer-shaped depression around the base of the plant and fill it with water, several times if necessary. The water will be put to good use as it soaks into the soil around the roots (where it is most needed), so this method cuts down on wastage.

8 Recycle plastic bottles

Plastic drinks bottles that you would otherwise throw away make a simple, low-tech water delivery system. Drill a hole in the base and leave the cap half-unscrewed. Then insert the bottle (upside down) into your container of compost with just the base of the bottle visible. Each time you water, fill the bottle and the liquid will gradually drain out of the bottle around the thread on the screw cap, slowly soaking through the surrounding compost.

9 Effective drainage

7 Saucer depression

Some containers have drainage holes in the sides, rather than the bottom, so that water can accumulate in the base of a pot and only drain away once it reaches the top of the drain holes. You can create the same effect by jamming a short section of pipe into the drainage hole. With a tight fit, you can get a watertight seal, and the pot will only drain when the water reaches the top of the pipe. Or you can buy pots without no drainage holes and choose to drill your own holes at a level that suits you.

10 Line a porous container with plastic

Containers with porous sides can be a problem, especially wooden ones such as boxes and half barrels. They draw moisture from the compost into the wood, then lose it to evaporation. Eventually, the containers themselves dry out, and the wood sections shrink, leaving gaps between them through which water will leak. You can get around this simply by lining the container with plastic before adding compost and plants. Then it does not matter how dry the wood gets. Remember to cut drainage holes in the plastic bag first.