Southern Ontario is blessed with ample access to fresh water. Unlike many places suffering from drought, water is plentiful here. But this is no reason to treat this precious resource as free. As you have learned in this issue, the food we eat requires enormous amounts of water. Any gardener will know that vegetables do better with a little bit of help from the sprinkler. But did you know that all water isn’t created equal? How, when, and for how long you water will dramatically affect the quality of your plants and help you reduce your water footprint.
Soil is full of spaces that fill up with water. Water is nature’s great solvent and transports nutrients to plants. Different types of soil retain water better than others, so it is important to know your soil. Water flows through sandy soil faster than clay, but it also dries out faster. Knowing your soil is the first step to knowing how much to water. Check out this link for an explanation of soil types and for an easy test you can do at home to optimize your watering strategy. The following tips can help you reduce how much you water while also growing better plants.
Keep it raised
Every time you walk on your soil, you compact it and decrease the tiny spaces between particles that fill up with water when it rains. Compacted soil is much more prone to run-off and during a large rain event, water is much more likely to pool on the surface. This means your plants will spend their energy sending roots to the surface to suck up that water. Shallow roots means less access to nutrients found deeper down and plants that are easily toppled by wind. Consider building raised beds that are small enough that you can easily reach with your outstretched arms. You’re much less likely to compact the soil and your plants will be much happier.
Keep it covered
Like you, soil doesn’t like to be naked, so keep it covered. Think about a forest: the ground is covered by a layer of leaves, pine needles, sticks, moss, or weeds. This layer decays and eventually becomes humus and adds vital organic matter and nutrients to the plants. By using straw or shredded leaves as a mulch, you not only reduce the amount of evaporation from the soil, at the end of the season you can lightly turn the organic matter into the soil and improve its texture and water retention ability. Mulching also reduces weed pressure and saves you time and money.
Keep them clustered
Not all plants have the same water needs and it is just as bad to over-water as it is to under-water. An easy tactic is to keep plants with similar needs clustered. Learn which plants are thirsty and which prefer drier conditions. Many herbs, for example, come from Mediterranean climates and will be damaged by too much water. Tomatoes, cucumbers, and zucchini like lots of water and benefit from drip irrigation that focuses on the roots rather than the leaves. Lettuce, on the other hand, likes to get wet and benefits from overhead sprinklers.
You can save a lot of water and improve your plants by choosing when to water. It is best to avoid watering in the middle of the day as those little beads of water act like magnifying glasses and can either evaporate too quickly or cause leaf burn. It is better to water in the morning, late afternoon, or evening. Watering in the morning is probably the safest bet. If plants have water on them overnight for longer periods of time, they become more susceptible to fungal diseases. A simple timer for your sprinkler can make sure you get the timing right.
Keep it slow
As a general rule, you want to water your plants less frequently and with an emphasis on slow, deep watering. It is better to water for a longer time twice a week than to water a little every day. Consider purchasing a soil moisture meter from your local nursery as it is easy to over-water when you go by how dry the surface is. These will tell you the moisture content where it matters the most, at the root level. Remember, shallow watering encourages shallow roots. Consider investing in an inexpensive soaker hose or a drip irrigation system, which can achieve efficiency rates exceeding 90% of water compared to overhead sprinklers and help stimulate deeper root growth. As a bonus, many drip systems don’t require a lot of pressure, so you can hook them up to a rain barrel and water your garden without city water.
There are many great resources to help you learn about water usage.
Click here to watch a video on how much and when to water the plants in your vegetable garden.
Click here to learn about more ways to conserve water around your house.