Be responsible with water
Water is a precious resource, so we need to use it wisely. When the weather is hot and dry water usage goes up and the amount of water available in the reservoirs and rivers goes down, so we need to think carefully about watering your garden during a heatwave.
Drip watering systems use a small fraction of the water a sprinkler system would consume, and makes much better use of that water.
Water at night
Hand watering with a hose on a hot summer evening will waste most of the water through evaporation. If we just wet the warm surface of the soil, most of the water will be lost to evaporation, with very little reaching the root zone.
If a timer is fitted to the system, the watering can take place at dawn, when the earth is cooler. The moisture will then have time to penetrate down to the root zone before it evaporates. A rain sensor can also be added to the timer so that it only waters when it is dry.
Use a drip watering system
Israel perfected the science of drip irrigation in the 1970’s when they discovered that they could water more effectively using much less water. The secret of drip irrigation is the slow, steady drip rate that allows the water to be absorbed directly into the soil. There is no droplet spray, so no evaporation as the water travels through the air, and as the surface of the soil is mainly dry, there is very little bed evaporation.
The main issue with border drip watering is customer perception. As the bed looks dry, customers perceive the bed still needs watering; turning the soil over with a trowel will reveal moisture just below the surface.
Concentrate on the pots and borders
A green lawn looks lovely but in reality, it is very rare for grass not to rejuvenate after a dry spell. Borders and pots are a different matter, so this is where the watering needs to be concentrated.
A drip system on the border with a timer fitted will ensure the planting will thrive even in hot, dry weather.
With tubs and baskets, the issue is that the pots will dry out quickly, so watering needs to be done multiple times per day. A hanging basket and pot watering system has drippers which will take water directly into the heart of the compost. With a timer the watering can be programmed to water morning and evening, with a top-up in the middle of the day. As no water is being sprayed, there is no danger of leave scorch.
Don’t wait until everything is very dry
If watering is left until the ground is baked hard, not only will the plants be under extreme stress, but the watering will also be ineffective as it will just run off the surface – this is the reason we get flash floods in summer. On a well-established bed, you can wait 2 or 3 days before watering, but any longer is likely to cause the plants to begin conserving water and reducing growth and flowering.
The secret of effective irrigation is to start early in the season as soon as the moisture levels drop, topping the soil moisture content regularly.
Mulching
Studies have shown that putting a mulch over the exposed soil on a bed can reduce the water losses through evaporating by as much as 25%.
The one issue to consider is the UK Water Regulations normally require dripline to be on the surface rather than buried, so a mulch may cause issues with this.
Hosepipe bans
Water companies have extensive powers to restrict the use of water when there are drought conditions. The last time there were widespread restrictions, the water suppliers allowed drip watering systems to be used if they were combined with a timer; they saw this as a good way of encouraging efficient use of watering.
