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Over the Garden Fence

Fall watering is important

Imagine a podium or soapbox and me standing in a town square. Got that image?

Ok, here goes my “sermon.”

As of Sept. 16, the U.S. Drought Monitor reports our area as “abnormally dry.” Have you been watering your trees, shrubs, and plants in the yard?  We have had such dry weather that there are not just a few plants that need to be watered, but a whole lot.

Water all plants, not just the obvious

Some are obvious like hydrangea or phlox, yet most really do not let us visually know they are suffering from a lack of soil moisture. Needled evergreen trees show this year’s growth just hanging down, especially the lower half, as they are supporting the newer more upward growth. Buds are smaller than they should be, which already tells us next season’s growth will be impacted.

The same holds true for all plants. Here are a few more examples:

  • Our oaks have seen a larger than normal acorn crop, yet those acorns are barely there and falling prematurely. Not enough water to fill those acorns out, so yes, even large, well-established trees of all kinds are in a droughty state. You may have noticed even the maple “whirlybirds” are smaller than normal.
  • In the flower garden, daylilies, which normally fade away towards the end of summer, may be already gone in the sunnier areas. Also, you likely have had to water impatiens and coleus more to keep them looking good.
  • Lawns are expected to go dormant as a cool season grass.  If left too dry too long, the  crowns will be completely desiccated and you’d be left with brown dead patches or entire lawns. About ½ inch of water every 3 weeks should keep the crowns alive.
  • Normally, the best time to seed a lawn is from the middle of August to the first week in September for our area. If you have been waiting on our normal fall rains to get things started, better get the sprinkler out. Keep the upper ¼- to ½-inch moist, but not waterlogged, to get the seed to germinate. Once you start the process you will have to continue to water to get the lawn established.

Water to minimize winter damage

While we get a “do over” with our annual plants in 2022, the same is not true for our established and perennial plants. Watering our favorite landscape plants now, and well into the fall, will lessen overwintering damage come spring. This includes tip dieback, buds being damaged or killed, and whole twigs and branches killed.

Water at a slow and steady rate

It is not just the upper few inches of soil that are dry, but well into the subsoil. Watering will need to be done on a slow and steady rate of flow. The best approach is using an open hose without any attachment at the largest rate of flow that does not run off the plant or area you are watering. Move the hose around to get water into the entire area you are watering.

Large shade trees should be watered from approximately 6 to 8 feet inside the canopy drip line to 6 to 8 feet outside of that line. This is where the majority of feeder roots are. The same can be said of evergreen trees too. Smaller shade trees and upright evergreens also have a dripline, but adjust that watering ring accordingly. Hint: Properly watering larger trees should take hours when done correctly.

Wrap up

I am about to get down from my soapbox now, but first, a quick summary, as every good lecturer will do:

  • Definitely water any newly planted trees, shrubs, and perennials, but as you do, also water all of your trees, shrubs, and perennials. This includes evergreens!
  • Water those newly seeded lawns, and if you don’t regularly irrigate your lawn, don’t forget to keep your grass crowns happy with at least a ½ inch of water every 3 weeks.
  • Conserve soil moisture with techniques like mulching.


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About the author: Richard Hentschel’s expertise extends across several subject areas with specialties in lawn care, fruit tree production, woody ornamentals, and home and community gardening. During his 45-year career in horticulture and agriculture, Hentschel became a well-known and respected expert for commercial and homeowner audiences, industry organizations, and media. He retired from University of Illinois Extension in April 2022 with nearly 30 years of service as a Horticulture Specialist and Educator in northern Illinois.