Normally, only 14 days a year reach 90 degrees or higher in Chicagoland. As of mid-July, we have already surpassed this number of days in 2020, with more 90-degree and above average temps forecasted.

During a normal growing season, your garden should receive an inch of water per week. However, inadequate precipitation (rain events) combined with extreme temperatures mean faster transpiration (evaporation), even if you do water. These conditions call for special attention to your garden.

In addition, when it’s hot and humid, disease and fungus thrive in such conditions. Watering will promote a healthy plant that will be better able to fend off diseases that would take hold of a weaker plant.

Here are watering tips to help get your garden through this hot and dry summer:
  • Water deeply. Doing so encourage deeper roots that will help keep the plant cooler in the summer heat as well as increase the water table available to the plant. After watering, dig down and make sure the soil is moist to a 6” depth.
  • Keep the foliage as dry as possible. To accomplish this, early morning watering is ideal, as less water is lost to evaporation and it will allow the soil to remain moist for a period, but give time for the foliage to dry once the sun comes up.
  • Newly planted plants will require additional watering as they don’t have an established root system to help keep the plant cool. Watering deeply encourages root growth. Daily watering may be required each day, and if temperatures increase above 80 degrees, a second watering during the hot part of the day will also help keep the plants cool and healthy.
  • Established plants also need watering. A 35-foot tall tree transpires 30 gallons of water on a hot summer day. During a dry spell, large trees must be watered to ensure good health and promote growth.
  • Be careful to not overwater. Roots need oxygen, and too much water will displace the air in the soil and prevent the roots from breathing. Use a rain gauge to help you measure the amount of water that has been applied to your garden.
  • For lawns, use an oscillating sprinkler for best results. Lawns will turn yellow and go dormant if stressed and not receiving enough water. Walk on your lawn. If the leaf blades don’t bounce back, your lawn is dry and needs watering.
  • If you have an irrigation system, periodically check that your plants and lawn areas are receiving water. Leaf growth from surrounding plants or an added feature, such as a bird bath, can block an irrigation head’s spray path. Cutting back foliage or relocating plants that obstruct the irrigation head’s spray path, or lengthening the height of an irrigation spray head, are useful ways to ensure all areas are watered.
  • Water plants before they need it. Water before plants show signs of stress. The most relevant sign of plant stress is wilting. Wilting is a natural occurrence that helps a plant slow water loss by exposing less surface area to the sun’s evaporative rays. This condition can mean insect or disease problems, but it’s mostly attributed to lack of soil moisture.
  • Use effective and inexpensive gadgets to help with watering.