Water-saving tips for the vegetable garden and container plants including when to water, how to hand water, using ollas, collecting water, & recycling water
This piece is in partnership with Gardena, Europe’s leading brand of high-quality gardening tools.
After a long, cold, and wet winter Britain is baking in summer sunshine. Here on the Isle of Man, we’re having one of the hottest and driest summers in memory. Fields that are usually lush and green are yellow and withered and let’s not even talk about the lawn. Our plants are thirsty!
With the heat comes public notices on reducing water usage and to avoid watering the lawn. That brings into question how we vegetable gardeners can keep our gardens watered while trying our best to not turn on the tap. These ten water-saving tips for the vegetable garden are here to help.
1. Water in the evening
The time of day that you water makes a huge difference in how much moisture gets to your plants. Watering in the heat of the day can mean quite a lot of it will evaporate from the soil long before it reaches any roots.
The best time to water the garden is early evening. Not only will it be cooler to work outdoors but less evaporation will happen. Give the moisture a full night to seep further down and you’ll end up saving a lot of water in the long run. If you can’t get to the garden in the evening, water it early in the morning. The earlier the better to help the soil soak up moisture before the sun starts beating down.
Another tip for if you garden in a community garden or allotment like me. Bring your own hose! There’s been a lot of demand for the hoses this summer and taking my Gardena hose trolley with has saved me a couple of times.
2. Mulch your soil
If you leave the soil around your plants bare, it will dry up and your plants’ roots along with it. Keeping your soil moist and healthy during summer means that you need to protect its uppermost layer. Cover it with a mulch of your choice: garden compost, composted manure, straw, grass clippings, mushroom compost, or another protective organic material. A two-inch layer of mulch (or more) will keep your soil from drying out. It also means that you have to water your garden less.
When using a watering can or hose, direct the water at the bases of the plants only. A gentle shower of water on the compost will make it straight down to where it’s needed without being wasted on the foliage.
One thing that I like about my new Gardena Comfort Bed Sprayer is the hold button on the trigger. It can really ache to keep the trigger pulled in while hand watering. Flicking that little switch locks the spray action though and I can release my grip. This is a really great feature if you get sore hands or have arthritis.
4. Use seep hoses & automated irrigation
Seep hoses work by allowing tiny amounts of water to seep through holes in the hose. It takes longer for the water to get to your plants but you can end up saving a lot more water by using them. Seep hoses can be buried under the compost and near to where the plant’s stem is and can even be attached to water butts instead of the tap.
Automated irrigation systems are set on timers so they water your plants slowly and without you needing to be there. I can recommend this inexpensive Micro-Drip-System for up to five pots. You can also get much larger systems for open garden spaces.
5. Collect rainwater
If you really want to save water, save it from your roof. In the case of a house, attach a water butt or two to the gutter and downspout system. You can also attach one to your greenhouse or shed. Every little helps.
6. Recycle water
Ordinary washing up liquid, shampoo, and soap are harmless to plants. That means that you could save your dishwater and bath water for use in the garden.
Using a plastic tub to do your dishwashing it makes taking it out to the garden very easy. In the case of greywater from the sink, tub, or washing machine you may have to either bail it out or install custom plumbing.
7. Use Ollas
Ollas are a simple and ancient way of watering crops in arid climates. Terracotta wicks water from inside out, which is why pots can get moist after you water them. A terracotta vessel sunk in the ground will slowly release water to the plants around them. You can purchase custom made ollas but they are dear. It’s better to DIY your own using terracotta pots — here’s how to do it.
8. Grow veg in containers
If you really want to save water in the garden, grow your plants in containers. Not just any containers but pots and planters that help control evaporation. Terracotta pots are the least effective for this, even though they are traditional. I have to water my terracotta strawberry pot twice a day in this heat. Unless you’re growing something that likes dry feet, stick with heavy duty plastic containers.
Although we’re all doing our best to reduce plastic in the garden, long-life pieces make sense. Take the Gardena NatureUp! vertical planter. I’ve been growing lettuces in it since April and have noticed that it needs a lot less water than I’d predicted. It also looks great and will last for years.
Starting with just three levels (see what it used to look like over here) I’ve just recently added another two on top. That’s five levels of growing space that needs only the smallest drink of water each day.
9. Water containers when the compost feels dry
People tend to run into trouble with watering containers through under-watering. Some also over-water and the plants inside can suffer too. In the winter I don’t water mine at all but that has to do with my wet climate. In the summer I’ll poke a finger in the soil to feel if it’s moist or not. If it’s dry, water it. If moist, leave it be for the day. Simples.
10. Watering with sprinklers
You might think that using a sprinkler can waste a lot of water. In fact, a good soaking with a sprinkler every week can be more efficient than trying to water your plants every day. Efficient in saving your time and also efficient at saving water over the course of the week.
Providing you have a good layer of mulch and you water in the evening, a sprinkler can be an invaluable water-saving asset. Figuring out how long you should run it can be tricky though. I remember the sprinkler being on in my grandma’s garden throughout the summer. It would be around dinner time and she’d move it around every now and again to make sure it all got a good soaking. She knew what she was doing.
An easy way to work this out is to place empty glasses around the area your sprinkler will hit. Turn the sprinkler on and leave it on for at least 20 minutes. Measure how much water is in the glass afterward, using a ruler. A vegetable garden needs about 1.5″ of water every week so if there’s 1″ after 20 minutes then add enough time to make up the extra half inch. In this case that makes 30 minutes of unbroken sprinkler watering.