Here in the Raleigh (North Carolina) area we’ve been having some really dry weather. With only a small amount of rain for most of the past 30 days, it’s been a dry spring.
Most of our established plants are just fine, coming out of dormancy, but if the trend continues as all those plants start needing more water, we’ll need to do some supplemental watering.
On the other hand, plants that have been in the ground 6-9 months or less may need supplemental watering now. Fescue lawns are also looking a bit parched. In this post I’ll discuss watering newly installed plants and in Part 2, I’ll look at lawns.
All new plants need to become established before they can use natural rainwater well and survive droughty conditions. Establishment really refers to the expansion of root systems from the rootball into the native soil. In general, smaller plants establish more quickly than larger ones. It is important to water new plants properly to get them established well.
Watering properly means watering deeply, watering at the roots and watering frequently enough (but not too frequently).
Watering deeply—be sure you water enough to really soak into the soil as deeply as the root ball was planted. If a “tree ring” of soil was created around your plants when installed fill that at least two times each time you water. The dike the ring creates allows the water to sit around the plant while it soaks into the soil. Without a ring, you may need to run water onto the soil very slowly to prevent runoff. Rings like this are meant to be temporary and should be broken down after about a year. Ideally you check the water in the soil after watering to make sure the soil is soaked deeply, a soil probe is great for this. It is also important to water the area directly around the ring to be sure there is available water just outside the rootball.
Watering at the roots—be sure the water you apply gets to the root zone of the plant. With new plants, that zone is right at the rootball, usually right under the upper canopy of the plant. In many cases the canopy can actually keep water from reaching the roots. So use a watering method that gets water right to the roots where it’s needed.
My favorite watering tool is a hand held wand. You can easily reach under the plant canopy to apply roots right at the base. Most wands should come with a nice breaker that allows a soft shower of water to fall. Drip irrigation is also great if you have an automatic system. Soaker hoses can work well, but will water between plants where you don’t need the water.
Sprinklers and sprayers are least effective and waste a lot of water—something of which we should always be aware.
Watering frequently enough (but not too frequently) —it’s always best to check the soil moisture before watering to make you actually need to water. Pull back the mulch near the crown of the plant—you are mulching aren’t you??—feel the soil underneath. If it’s moist at the surface, check back tomorrow. If it’s dry an inch or so down, get the water out.
Soil type, weather and plant type, size and location will determine how often you need to water. Sandy soil doesn’t hold water well, clay does. Sunny, windy weather conditions cause plants to use more water. Temperature doesn’t make as big a difference as sun and wind do. Broad leaved plants tend to use more water than narrow leaved ones. Plants with hairy leaves tend to use less water. In winter, evergreen plants will use more water—especially here in NC. Plants in sheltered shade may need less water, unless that shade is provided by other plants which may be sucking up all of the available water with their big, established root systems.
Watering too frequently will either drown your plants or, if frequent waterings are light, will encourage roots to develop shallowly (where the water is).
You should check for watering about 2-4 times per week for the first month after planting. After that 1-3 times a week should be enough. Once plants are established, they should get by on 1” of water every 1-2 weeks. Get to know your plants, your soil and watch the weather to learn your property’s idiosyncrasies.
So check those plants, water correctly and help them get well established.
Next time: Part 2—Efficient lawn watering.