By the time July rolls around, the questions we get start to shift. It is not “what should I plant” anymore, it is “is my garden going to make it.” Fair question. Heat and humidity in Illinois can be brutal on anything that went into the ground this spring, and even established plants can start showing stress when the temperatures sit in the 90s for days in a row.Here is the part that surprises people: not everything in your yard needs the same amount of attention right now.
Newly planted trees, shrubs, and perennials need the most water
Anything planted this year, whether it is a tree, a shrub, or a perennial, is still building out its root system and has not earned the right to be ignored yet. These are your priority. A deep soak two to three times a week is usually better than a quick daily sprinkle, since shallow watering encourages shallow roots, which is exactly what you do not want heading into August.
Established perennials and native plants can handle the heat
Established perennials, especially natives, are a different story. If you planted coneflowers, black eyed susans, or other prairie natives a year or more ago, their root systems are likely deep enough to find their own water most of the time. Watch for wilting in the late afternoon as your cue, not the calendar.
Lawns are built to go dormant in summer heat
Lawns are the one place we will tell you it is okay to let nature take its course. A brown, dormant lawn in July is not a dead lawn. Cool season grasses in our area are built to go semi-dormant in extreme heat and bounce back once temperatures drop. Watering a lawn just to keep it green through a heat wave uses a lot of water for a cosmetic result.
Containers and hanging baskets dry out the fastest
Containers and hanging baskets need the most attention of all. Without soil around them to buffer the heat, pots can dry out in a single hot afternoon. If you are growing annuals in containers, plan on checking them daily during a heat wave, sometimes twice.
The simplest test still works best. Stick a finger two inches into the soil. If it is dry at that depth, water. If it is still damp, give it another day.
Stop by Hornbaker Gardens in Princeton, IL for expert advice on keeping your garden healthy through the hottest part of the season.