You can use less water in the garden by:
- Careful watering
- Partially slowing drainage
- Collecting rainwater
- Careful planting
Timing and directing your watering can make a big difference in the amount of water your plants receive. Much of this is due to evaporation, and you can minimise this by watering only in the early morning or late evening on hotter days, and by directing water at the plants’ roots rather than all over them.
Likewise, a fine overhead spray from a hosepipe nozzle or sprinkler will do less good than using a watering can to gently pour water on the base of the plants. The only thing to remember is to avoid hitting fragile seedlings with the full force of the water and damaging delicate stems.
A light sprinkle of water in hot weather can mostly evaporate away from the leaves and the soil surface, doing very little good, so in these circumstances the occasional full soak is better than regular ineffective watering.
Soaker hoses that lie on the surface of the ground near to your plants can be quite efficient, especially if your crops are fairly closely sown together, so you don’t end up soaking empty areas at the same time. You can even pick them up in pound shops sometimes, although you might be better off in the long run if you buy something more robust.
Mulch sits on the surface of the soil, preventing too much water from evaporating up out of the ground. You can mulch with various natural substances, including leaf mould and old or spent compost, and you need to apply a generously thick layer for effectiveness. You can also mulch with new compost, which adds more nutrients to feed the plants as well as protecting their roots and slowing evaporation.
Mulch is especially good for plants that have shallow roots that poke through the surface of the soil in places. That includes courgette and raspberry plants, for example. Try not to go right up to the stem with the mulch, as this can cause the stem to weaken or rot.
You can also use artificial forms of mulch, including commercially-available mulch sheets. These are usually semi-permeable, allowing a little water in, as well as preventing much of it escaping, but some of them can be a bit too impermeable and you may need to water under them from time to time.
Mulch also has the advantage of suppressing weed growth. Weeds are generally bad for your plants, and even if you decide not to use mulch then it’s good to weed regularly from the water conservation side of things – weeds compete with your crops for water as well as light, space and nutrients
Partially slowing drainage
It’s not good to try to completely hold up drainage, as during rainy spells your plants can be irreversibly damaged if they’re left with their roots submerged in water for long periods. However, if you’re growing in containers, they are very prone to drying out quickly, especially if you have terracotta pots or hanging baskets.
Terracotta pots can easily be partially lined with plastic sheeting, such as old compost bags, especially if you put a few small holes in them. You can also buy types of compost that are naturally more water-retaining, and I’ve also heard that compost made by worm farms is especially good at holding the right amount of water for plant health.
You can also buy water-retaining gel mats to put inside hanging baskets, or water-retaining ‘crystals’ to mix in with compost. I’m not sure about the environmental impact of using the crystals, although they seem to be fairly inert from the looks of things.
Saucers and drip trays can also be placed under pots to catch water, although care is needed to make sure plants aren’t sitting in water for days on end. This is easy enough with small and medium size pots, as they can be lifted up to allow the saucer to be drained, but it might be more difficult with bigger planters.
If you can collect rainwater you’ll be less dependent on tapwater, and some plants fare much better with it, for example, blueberries. However, it’s important to make sure the water doesn’t become stagnant as bacteria and algae can make their home in it too, so try to keep it moving, and look into natural products that have an anti-bacterial effect.
Collecting rainwater usually involves buying a water butt, and attaching it to a drainpipe to collect water from a roof. If you’re growing vegetables on a very tight budget you may find this purchase is more than you can afford in one season, but you may find one being given away on Freecycle, Freegle or the free section of Loot. You can also save money if you buy them in the winter, when garden centres are clearing out their warehouses.
It’s helpful to think about where to plant crops, and what to plant. For example, anything planted too near to a hedge or the roots of a large tree is likely to suffer from the larger plant’s water-drawing ability and requirements.
Planting too near to a wall means that your plant may miss out on natural rainwater, so it’s best to either plant further away or use water-retaining features such as mulch.
Sandy soil drains very quickly, so it’s a good idea to work some organic matter into it before planting crops there.
One final tip is to create microclimates. For example, you can grow sprawling plants such as pumpkins and squash as a sort of living mulch around the base of taller plants such as sweetcorn, which seems to be to the mutual benefit of both crops. In dry weather you can also group plants in pots closer together as this seems to partly reduce evaporation.
Do have any tips of your own to help save water in the garden?