Plant Care: Applying additional water

Properly watering landscape plants is the most important maintenance chore for any gardener. A pre-set schedule, while attractive to people, is impossible since a plant’s water needs depend on many factors including air temperature, soil temperature and type, wind, humidity, sunlight, plant type and the depth of the root system.

The only way to correctly determine if a plant needs water is to check for soil moisture in the root zone of the plant. With a small shovel, dig down to a depth of approximately 6-8” in an area close to but not directly in the plant’s root zone. Remove a handful of soil from the bottom of that hole and squeeze it in your hand. Gently poke the soil and observe it. If the soil sticks together like cookie dough, it has enough moisture. If it readily falls apart, it is time to apply water.

It is recommended that plants receive a thorough watering at their base with a slow steady stream out of a garden hose or soaker hose. Or you may prefer to handwater using a breaker that is similar to a showerhead. Lawn sprinklers and mist nozzles do not do an adequate job of watering landscape plants even when they remain on for extended periods of time. The most important point is to apply water in a slow steady stream so less is lost through runoff and evaporation and the maximum water is absorbed by the root system. Time of day is not critical if you are applying water to the soil and not to the foliage of a plant.

Keep in mind the size of the root ball you are watering and/or the depth of the root system. This will guide you in how much water to apply. Water should be applied to the entire depth of the root system. Different size plant material with differing size rootballs will require different watering schedules and different quantities of water. It is unusual for all plants in a garden to require water at the same time and to need the same quantity of water. Since soil dries out at the surface first before reaching downward, well established plants with deep roots will need additional water less frequently than plants with roots closer to the surface or plants recently installed.

Overwatering can be as detrimental to plant health as underwatering. A healthy root system needs oxygen as well as water. Unless you are growing a bog or water plant, a waterlogged soil lacks oxygen and will lead to the plant’s demise. Leaf wilt is not always a definite sign of a plant that needs water. It cannot be overstated that the only way to determine a plant’s moisture needs is to check the surrounding soil!

Comments on rainfall and soil moisture’s part in winter protection: Generally speaking, most plants will need a thorough, deep watering every 1-3 weeks throughout the growing season. In our area of Ohio, Mother Nature assists us in April and May but we need to be ready to pick up the slack when the spring rainfall decreases and the weather warms. Do not be fooled by summer rainstorms. They rarely provide water to the depth needed since they often come fast and furious with much of the rain running off the soil before it can be absorbed. Good, soaking, Autumn rains can begin as early as September or as late as December. Do not put that hose away on Labor Day! The best winter protection you can provide for your plants would be to make sure they do not go into winter drought stressed. If Mother Nature is not providing rain, check the soil and apply water to thoroughly soak roots the last half of November.