Plants need water – that’s a fact. And many vegetable crops need quite a lot of water (along with sunshine and nutrients) to produce the tasty roots and fruits that nourish us year round. Part of the goal of organic gardening is to grow food sustainably. We want to have minimal impact on the environment, and leave the soil healthier than we started with. So what are the ways we can use good watering practice in our sustainable garden and farming models?
1. Whenever possible, water early in the morning. This is when the soil is coolest, so the water can be delivered to the crop with minimal waste to evaporation. By watering earlier in the day, the garden will not be damp or wet at night. A wet garden at night is the perfect place for woodlice, slugs, and snails to breed and prosper.
2. Water less frequently, but more deeply. Plants get water through their roots, and less frequent watering encourages them to build deep root systems. If you water lightly, a lot of the water that goes onto the soil will evaporate right back out into the atmosphere again, especially if you’re watering on bare soil. How can you find out if you’re watering deeply enough? At the beginning of the summer, water your plants and dig into the soil to see how deep the water has gone. If you only see a centimeter or two of damp soil, continue watering.
3. Water close to the soil, and avoid overhead watering. Place your irrigation near or beneath the soil surface rather than spraying the top of the plant. The plant’s leaves will act as a sun umbrella, reducing evaporation so that more water has an opportunity to soak into the soil. Many plants, like tomatoes and squash, will be at increased risk to diseases like Late Blight and Powdery Mildew if their leaves are frequently soaked by overhead watering. A much better method is to use drip irrigation systems, which supply a very gradual but constant supply of moisture. For containers and raised beds, use water delivery systems with long spouts to reach in and get water close to the soil around the bases of plants. The Dramm Two Litre Watering Can has a very long spout for this purpose.
For sapling trees and large shrubs, consider a watering bag, which releases water over a long time, allowing for deep soil penetration. Large areas such as lawns and wildflower beds are best served by high quality sprinklers, but be accountable for water use. Take advantage of a simple water timer. Happily, the thinking about garden hoses has shifted, and now hoses are available that use BPA and phthalate-free plastics and no lead in the fittings.
4. Mulch! Apply a layer of organic matter to the surface of the soil between and around plants’ stems. Not only will mulch help conserve water in the soil, but it will drastically reduce weeds from becoming established. As mulch breaks down, it adds organic matter to the soil, promoting microbial action for healthier soil. Mulch can be made from pretty much any organic material that will biodegrade, but the common mulches are bark, leaves, straw, and well rotted compost.
5. Design your garden to store water. Build good soil with ample organic material, so that the water that goes into the soil will stay there. If you are on a slope, create swales, long ditches, or terraced dents in your garden that capture water, letting it filter in slowly.
6. Collect water! Use the roofs of your house, greenhouse, and garden shed to collect water in dedicated rain barrels. Every bit of water that the clouds offer us counts for water not taken out of our shared supply. Taking advantage of existing natural systems is at the very heart of organic gardening, and few more obvious natural resources exist than rain water. Don’t waste it!
7. Recycle water. Consider hydroponic and aquaponic solutions that circulate water through specialized planters. There are scores of excellent DIY hydroponic systems described on YouTube and other open source media. Other simple systems like vertical gardening allow water to drain from one container to another, supplying each container over a short time.
8. Know your plants. Established perennial plants may only need a few centimeters of water once a week, but other plants like tomatoes are water hogs. It’s alright if plants droop a little in the intense heat of the day, but it’s a clear sign that more water (or deeper watering) is needed in the morning. Containers and raised beds tend to drain faster than garden beds set in the ground. Be sensitive to drainage and evaporation as natural processes, and plant accordingly.
9. Consider xeriscaping as a landscaping option. Xeriscaping is landscaping with water conservation as its central theme. More on xeriscaping here.
Watering well is about knowing your plants and working with your garden to create a schedule that works. This year, become a water-savvy gardener, take action to change the amount of water you use to grow healthier, less water-stressed plants. Use good watering practice to do your part for the environment in the comfort of your own organic vegetable garden.