New plants need at least 1 soaking before winter
Q: I have done a lot of planting inmy garden over the last couple of years andwonder how late I need to keepwatering. Thiswarmweather is confusing, and I do not want to overwatermy plants, which have lost most of their leaves.
— JermaineAndersen, Evanston
A: You should probably bewatering your new plantings again this year, even thoughwe arewell intoNovember. It’s easy to forget aboutwatering once weather turns back to more normalNovember temperatures. If you have not beenwatering this fall, the dry soil conditions and spell of unusuallywarm weather in earlyNovember have put a lot of stress on trees, shrubs, perennials and ground covers installed over the last couple of years in your garden.
Certain areas of Evanston have very sandy soil, making supplemental water this fall even more important for plants that are not yet established in the garden. Even plants in their third season in your garden will benefit froma good soaking at this time.
During the growing season, plants that are dry will wilt or have foliage that yellows or changes to an off-green color as they start to experience drought stress. Deciduous shrubs lost their leaves as they went into dormancy, so you will not get the normal signals that a dry plant gives. Evergreens that start turning an off color of green or dropping excessive leaves at this time need quick attention. Plants that are dormant are more resilient to drought stress, so permanent damage to plants due to dry conditions will take longer to occur.
Double check the soil moisture by carefully spot checking a few areas of the garden at the base of the plants. If you have an automatic sprinkler system, it should have been shut down and winterized by nowto avoid damage to pipes and sprinkler heads fromfreezingwater. Use a garden hose towater at the base of the plants. This may take some time but will ensure the plants get a good soaking.
The foliage of evergreens can shedwater froma sprinkler to the outside of the root ball, leaving it dry. As a tree establishes over the first two to three years, the roots will growout into the surrounding garden soil.
It’s difficult to give you specific instructions for watering, as there are many variables based on a garden’s growing conditions. Gardens with sandy andwell-drained soils need more frequentwatering to get the plants established, since the soil will dry out more quickly than heavier clay soil dries out.
You should give your new plantings at least one good soaking this month and possibly more ifwarm and dryweather persists throughNovember.
For more plant advice, contact the Plant Information Service at theChicago Botanic Garden at plantinfo@chicagobotanic .org. Tim Johnson is senior director of horticulture at the Chicago Botanic Garden.