Article updated July 15, 2022
A mixture of oxygen and hydrogen, water is one of life’s fundamental elements. Like every other living thing, plants require it. However, getting the timing and volume just right can definitely be a challenge. Here are a few watering recommendations that will help your garden thrive.
A Few Basics
There are several watering principles that almost always apply. For instance, when you re-pot a plant, be sure to water it. If you have a plant in a big pot, then it will become dry at a slower pace than plants that are growing in small pots. If you have your plants displayed in areas with an abundance of bright sunlight, then they’ll become dryer than plants that are in low light areas. High humidity levels in the air will keep the soil wetter longer than dry air.
Watering Depth Guidelines
Watering depth guidelines for plants depends on how big a plant is and its type. For instance, you’ll need to consider whether a plant is groundcover, a shrub or a tree. You will also need to make sure that a large tree has more water than the groundcover around it. The reason for this is that big trees have larger root zones than smaller greenery. To keep your plants healthy, try to wet the full root zone every time you water.
What Depths are Best for Plants?
In the plant world, there is a 1-2-3 watering rule to help gardeners remember how deep to water their plants. Annuals, groundcovers and cacti are considered small plants. Water them to a depth of 1 foot. Shrubs and bushes are medium sized plants, so plan to water these to a depth of 2 feet. Trees are large plants, and you should water them to a depth of 3 feet.
Measuring Water Depth
To see how deeply you’re watering your plants, a soil probe will give you the most accurate reading. Soil probes are specialized tools created just for the purpose of measuring your soil’s moisture, but a long screwdriver can also do the trick. To test the depth, slide the probe or the screwdriver down into your soil an hour after you’ve watered your plants. The probe or screwdriver will descend into wet soil smoothly, but when it reaches soil that is dry, it will be hard for you to send it down more. Continue watering your plants until it’s easy for you to press the soil probe down far enough to reach the proper watering depth.
What About Watering Width?
Once you have established plants, you’ll want to consider how far out you’re watering them. In most cases, a plant’s water-absorbing roots are close to the dripline. This is below the outer edge of its canopy and away from the plant’s stem or a tree’s trunk.
How to Use a Soaker Hose
A soaker hose is a great tool to help you water to the right depths. Soaker hoses are the perfect addition to your irrigation system because they allow water to seep out at a gradual pace - soaking the soil slowly rather than creating puddles on top of dry soil. Using a soaker technique will give your soil time to absorb the water.
Available at 25-foot, 50-foot, 75-foot and 100-foot lengths, soaker hoses can easily be wound through your flower beds or be placed around trees or shrubs. Soaker hoses offer the same benefits of a professional irrigation system, but because they’re easily moved, they’re a great adaptive solution for areas in your yard needing extra attention.
Considering the Seasons
In the summer when the sun is hotter and more intense, it’s advisable to water plants like succulents more often. Try to water them once every other week instead of once a month like you do during the other seasons. If you have ferns or tropical plants, give them water every week. These types of plants need their humidity levels to remain elevated when it gets hot. There are ferns that prefer their soil to stay moist, but don’t allow the soil to remain soaking wet. Try to keep it damp.
Trees also need more water in the hot months. During the spring and fall, it’s a good idea to water desert-adapted trees once every two weeks or once a month while in the summer, you’ll want to give them water every seven to 21 days. In the winter, you can extend it to once every 30 to 60 days.
For more general watering information, read the following articles:
How to Choose a Garden Irrigation System
Garden Watering Made Easy with These Top Tips
Everything You Should Know About Deep Watering
How to Keep Outdoor Plants Watered When You're on Vacation
A Guide to Water-Efficient Gardening
Plants and Water—A Brief Look at How Water Affects Plant Growth
Waterlogging—What It Is and How to Prevent It
Does Watering Plants with Soft Water Help or Hurt?