The recent hot-dry-wet weather lately has made life really difficult for plants. Watering them may seem an easy task, but follow some golden rules to ensure the best possible results.
best time to water a garden, and how?
Watering every day for 15 minutes at a time may be convenient for you, but it can be disasterous for the plants. Frequent shallow watering will cause a plant’s roots to stay near the surface, where they will quickly dry out. It’s better to give the garden a good soaking less often.
Gardens are best watered early in the morning to reduce evaporation. Evening watering leaves water on the plants overnight, which can encourage fungal diseases.
Collect as much water as you can in water butts. It’s not only economical but is the best water for all plants except seedlings. Tap water is better for them as it’s sterile.
This is water that’s been used once in the house, and then collected. Only use this water within 24 hours of collecting it – after that, bacteria can multiply rapidly, turning your grey water black!
Avoid using grey water on edible plants as it may add more harmful bacteria to the soil than regular water. The dilute soap residue won’t cause too much of a problem with ornamental plants – remember that your great grandma probably chucked her washing up water over the roses to kill off aphids. However, if you have a water softener in your water system, don’t use it as the salts used can harm the plants and soil.
Aim to completely wet the rootzone of your lawn each time you water, and the rule of thumb here is to aim to apply around 2cms of water (which will then seep down 15cms). You can test this by pushing a sharp tool such as a screwdriver down into the soil, about an hour after watering. It’ll glide through the watered soil, but be difficult to penetrate dry soil.
I’d recommend not using a sprinkler as this gives you a false sense of how much water actually hits the spot.
Green vegetables are in fact 80-95% water, so it hot weather they will be the first to wilt. I don’t know who measures this sort of thing, but you might be interested to know that an average tomato plant transpires about 135 litres of water during a season. That’s a lot of water!
Water retaining granules were classically meant for pots and baskets, but now I’m putting a sprinkle of them into each new planting hole, and mixing well with the soil. These should make your watering 70% more efficient.
A mulch of well rotted stable manure will not only conserve moisture, but suppress weeds, re-mineralise soil and improve its structure. Apply after liberal watering.
Auntie Planty offers garden problem solving sessions in your own garden. Her advice is only a phone call away (020 8892 9243)
© 2011 Valerie McBride-Munro