Similar to other garden chores, watering is an acquired skill that comes from hands-on experience, some science-based knowledge and lessons learned from more experienced gardeners. Here are ten simple tips to help keep plants healthy and conserve water.
1. Water at the Right Time of Day
Watering your plants during the hottest part of the day doesn’t make sense, as evaporation is more likely to occur. I like to water early in the morning to give plants a nice cool drink to start the day. If you prefer, you can water later in the day when temperatures lower. In particular, on very hot days it can be better to water in the evening to provide more time for moisture to soak deep into the soil overnight.
Black-eyed Susan (Rudbeckia hirta) grows well in dry conditions.
2. Water Soil, Not Leaves
Plant physiologists teach us that some water is absorbed through the leaves, but the bulk of water uptake is usually done through the roots. Water-wise gardening involves targeting your pour around the base of the plant, not onto the leaves. For that reason, sprinklers and nozzle sprays connected to a hose aren’t always the most efficient way to water.
Nonetheless, a good spray on plant stems and leaves does wash away garden pests such as aphids and spider mites. During dry, dusty, hot spells, a gentle spray also removes dust build-up, making photosynthesis more efficient.
3. Avoid Over or Under-watering
There’s no magic formula to water-wise gardening. How frequently you’ll need to water will depend on plant choices, soil type, seasonal weather conditions and your property’s drainage patterns. Clay soils tend to retain moisture, while sandy soils drain quickly. Regardless of soil type, adding organic matter such as well-rotted compost will help to improve soil structure.
Plants show signs of overwatering when their leaves turn yellow or a lighter shade of green and young shoots appear wilted. Root rot can occur. Overly wet soil smells swamp-like, and algae and mushrooms may appear. In contrast, under-watered plants droop and appear lifeless, and their leaves wilt, curl or drop off. Soil will feel dry and pull away from the base of the plants.
If you examine only the leaves, however, it’s sometimes tricky to know if plants are suffering from too much or too little water. You need to feel the soil, squeeze it and smell it. By doing so, you’ll learn how to water your plants only when necessary.
4. Water Wisely
Overall, plants depend on an even amount of moisture. Fast-growing, edible plants in vegetable beds – especially those in raised beds – and container plants require more frequent watering than garden-bed plants. Slight drying of the soil between watering promotes vigorous root growth. As roots grow, they have access to more moisture.
This vegetable container needs frequent watering.
One simple test is to stick your finger deeply into the soil just after watering. If the soil feels dry beneath the surface, a second round of watering is needed. If your finger is moist and soil sticks to it, watering is sufficient. Alternatively, you can use an outdoor water meter to measure.
Remember to also water trees and shrubs (especially younger ones) until they’re well established and also during long heat spells. After planting, create a water reservoir by making a circular ring of soil around the base of the tree at the edge of the root ball to prevent water from washing away.
The author created a water reservoir at the base of this young tree.
5. Use a Rain Barrel
Harvesting rainwater has many benefits. This water is full of nitrogen from the atmosphere that will make plants green. In addition, it’s usually a good temperature for plants. By contrast, tap water tends to be colder and may contain added chemicals such as chlorine and fluoride.
Using rain-barrel water in a vegetable garden, however, is not advised because of risks from harmful chemicals that may leach into the water from asphalt and other roofing materials after it lands on the roof and travels along gutters and down the drain spout to the barrel. Vegetable growers should also test well water regularly.
Harvesting rainwater in a rain barrel has many benefits.
6. Use Mulch
Spreading mulch on a garden bed prevents water runoff and helps soil retain moisture. Spread about 3” of mulch, taking care to space it away from your plants to enable good air circulation and prevent fungal or bacterial infections.
Mulch also cools the soil and saves time you’d spend watering and weeding. As plants grow larger and the canopy size increases, they will require less mulch each year. Placing plants closer together will also shade the soil and conserve surface moisture.
Mulch helps retain soil moisture and deters weeds.
7. Water New Plants Often
Newly planted perennials or annuals require extra watering. Plants in pots tend to have small root systems that dry out easily. Once transplanted, their roots need time to become established. Water them every few days or so for the first two weeks. After that, water only as needed. Always transplant early in the morning or later in the day, preferably on a cool, overcast day, to prevent the plant from drying out.
8. Water Deeply
It’s better to water less often but deeply. Frequent, shallow sprinkling of water encourages plants to form more roots near the soil’s surface, which makes them more susceptible to damage from sudden heat and drought, as well as soil compaction. Deep watering fosters stronger, healthier roots that are better able to adapt to changing weather patterns.
9. Choose Your Watering System Carefully
Some gardeners use a watering can to control the flow and amount of water. Others prefer a soaker hose, a porous tube that seeps water into the soil, strategically positioned on the ground surrounding the plants. A drip irrigation system, often used in vegetable gardens, works in a similar way but has flexible plastic tubing with tiny holes or emitters. Underground irrigation systems have pipes buried beneath the soil that usually function on a timer. Such systems can make watering easy, although they are usually more costly. Different kinds of sprinkler systems, garden hoses, nozzles and water wands also are available. Whatever you choose, the key is to water intelligently.
A soaker hose provides a gentle misting of water.
10. Grow Tough Plants, Water Less
All plants need water, but some require more than others. A healthy lawn, for instance, requires lots of water to stay green – about 1 1/2” of water per week.
In my garden (zone 5a), I rarely water because I grow tough, drought-resistant ornamental plants. These include many native plant species suitable for our dry-summer, cold-winter climate. I also grow an array of Mediterranean herbs such as lavender, thyme and sage, which are ideal for hot, dry growing conditions.
Purple coneflower (Echinacea purpurea) is a tough plant that requires minimal watering.
Less frequent watering helps keep my utility bill low and fosters good stewardship of this natural resource. It also gives me more time to relax in the garden with a thirst-quenching drink.
Text and photos by Julianne Labreche
Julianne Labreche is a freelance writer and garden enthusiast who volunteers as a Master Gardener and Master Naturalist in Ottawa.