While last summer’s drought risked turning Canada’s gardens into a bone-dry desert, this year’s sudden and extreme rainfall threatened floods of Biblical proportions. As the visible symptoms of climate change begin to intensify, plants are having to contend with more unpredictable conditions. In this time of weird weather, what are the safest watering practices for our plants and the planet?
Supplying your plants with sufficient water is the most important part of gardening. While proper fertilizer and nutrient application can go a long way in helping your plants achieve their maximal potential, all plants will die without enough water. The trick is, what constitutes enough will not always be the same from one plant to another. Some vegetables, like those in the Cucurbitaceae family (melons, squashes, gourds) require large amounts of water to produce fruit, while other vegetables, like beans, can do more with less.
In times of drought, it is especially important to water your garden. For ecologically-minded and conservation-oriented gardeners, it is equally important to pay attention to your methods, since your watering practices can potentially further contribute to water scarcity. In the summer, municipal water usage increases by 50%, in large part because of lawns and gardens. According to Canadian Living magazine, Canadians actually have the second highest per capita water consumption in the world, with an average 335 litres consumed per household each day. While we gardeners tend to think that we are friends, not foes, of the environment, water conservation is one area where we could all be a little smarter.
The good news is that there are simple ways that you can drastically decrease your muddy footprint around the garden. Actions as easy as watering at the right time of day, using the right devices, and for the proper length of time can all make a significant difference.
The Right Timing
When it comes to watering, timing is key. You can drastically reduce the amount of water you use to nourish your plants simply by avoiding watering during sunny peaks. On hot summer days, the sun is often strong enough to evaporate moisture before it is absorbed by the roots of your plants. As a general rule, do not water after 9 a.m. or before 4 p.m. Instead, water first thing in the morning or just after dinner. Watering when temperatures are cooler will help the soil retain moisture and give plants sufficient time to absorb what they need.
Not only is midday watering inefficient and wasteful, it can also harm your plants. According to Urban Farm magazine, “on really hot days during mid-day hours, plants can be scorched by overhead watering. Water acts as a magnifying glass that focuses the sun’s energy and heat on plant leaves, so you may find your entire garden burned to a crisp the day after an early afternoon bout with a house.”
Since this summer has been particularly wet, overwatering can also be an issue. If you notice that the leaves on your plants are turning brown and falling off, your soil might be waterlogged. Though a really hot afternoon might make the soil appear to be dusty and dry, the top layer of soil in your garden is not always an accurate representation of what is happening beneath it. To determine whether a good soaking is in order, try “the finger test:” stick your entire finger two knuckles deep into the ground. If it still feels dry down to the second knuckle, it is time to water. If the soil feels moist, give it another day.
People often associate wilting with a lack of water, but sometimes the afternoon heat can cause plant leaves to wilt even when water is not the issue. If a plant is wilting in the morning, it is a sure signal to get the hose going, but if the plant is wilting in the afternoon of a really hot day then it is better to wait the night and see if they regain their composure on their own.
Some vegetable gardeners also advocate letting your soil dry out completely before watering. Too much water or a too-regular application of water can lead to waterlogged soil and a host of unwanted fungal problems. Some claim you can avoid this by watering exclusively in the early morning hours (before 9 am), which would give your plants enough time to absorb what they need before the sun dries out the excess.
The Right Devices
Not all watering methods were made equal. Overhead sprinkler systems are more prone to evaporation, and less targeted in their approach. Often, water from overhead sprinklers ends up giving free drinks to driveways, sidewalks, and patios. In other words, they can be quite wasteful.
If you have a small scale, personal garden, hand watering is your best bet. When hand watering, do your best to water at ground level, instead of showering above the leaves. When you are thirsty, do you pour water in your mouth or on top of your head? The same reasoning (in this admittedly crude analogy) can be applied to plants. Since plants absorb water by their roots, there is little to be gained from watering from above. Get low, get dirty, get under those leaves, and get your nozzle as close to the ground as possible.
If it is time to buy a new watering can, you can help improve your efficiency by choosing a can with very small pinholes. The smaller the hole, the more it mirrors a slow and light rainfall, which is the ideal watering scenario for your plants and garden.
For some of our on campus sites, we built self-watering containers. Container gardens often require a lot of water, since the small space dries out quicker on sunny days. Self-watering containers help address this issue by using a tube to feed into a reservoir of water at the bottom, which allows for greater moisture retainment. They can often go an entire week without a refill, greatly reducing the amount of water that gets used to keep your containers plant-friendly.
If you have a slightly larger row garden, it might be worth investing in a buried drip irrigation system. We use this system on our rooftop garden above the engineering building. These devices are slow and direct in their water application, and since the water is applied underground, they greatly limit evaporation and helping plants build stronger root systems. While impractical for a container garden, these are a perfect choice for water-conscious gardeners with slightly bigger plots. It is often claimed that drip irrigation systems save 50% more water than overhead watering methods.
The Right Soil
Adding large amounts of organic material and fertilizing your soil regularly with compost can do wonders for water conservation. Soil rich in compost and organic material can be better at trapping moisture, and making that moisture more accessible to plant roots and root systems. Sandy soil dries out quickly, while wet clay can compact quite easily and make it difficult for plants to absorb water. Soil that is rich in compost will be better at reserving moisture in a reachable form for those hot sunny days when your plants will definitely want a drink.
Mulching can also go a long way to ensure that your soil is retaining moisture. Spreading a layer of mulch such as straw or wood chips can keep your soil away from the sun’s drying rays, while also reducing the amount of weeds whose roots compete with your prized peppers for moisture.
- Tips to Save Water in Your Garden (funflowerfacts.com)
- Good watering makes good gardens (aurorasentinel.com)
- Summer gardening tips (shedforce.com)
- Don’t Let Summer Heat Take a Toll on Your Garden (healthylifestyleplus.com)