A: You might, but let’s ask a couple of questions first.
• Has the watering been adequate on the days you watered? Sprinkler systems will rarely water newly planted trees and shrubs adequately. They’ll help, but there’s no substitute for occasional, deep hose watering. New plants need a good amount of water! If your only source of irrigation has been a sprinkler, the answer is usually, yes, you should.
• Is the plant drought tolerant, or not? Most drought tolerant plants, such as yucca, sedums, agave, Texas sage, and the like, would best be watered sparingly in comparison to all your other landscape plants. Twice a week would have been plenty all summer, and less as we cool down. These plants probably don’t need more watering.
• Have I checked the soil for moisture? With a good coat of mulch, your plants may be fine on water in the soil, and just simply in a bit more sunshine or heat than they like. Check the soil to the second knuckle of your finger (the soil, past the mulch). If the soil is wet that far down, watering shouldn’t be necessary. If it’s dry that far down, soak it well. Even if the plant has crispy edges, like your Japanese maple, if the soil is wet, it’s wet; and more water won’t help.
Even for plants that may have gotten too dry, keep in mind that temperatures will be falling an average of two or more degrees every week at this point forward for quite a while, and that your plants will gradually need less water as that occurs. Water those plants a bit more than you have for now, but don’t go crazy with it. You can go from one extreme to the other; burning a plant up because the soil dried out, then following it up by drowning it after to try to mend the damaged plant.
Burton specializes in diagnosing and solving plant problems. If you have a question for Burton, please email him at burton@covingtonnursery.com and include photos showing the problem.