Protect tender plants from coming freezing temps
For me, the summer season has passed by too quickly as it’s already time to think about fall gardening. The average first frost at the Chicago Botanic Garden is Oct. 15, though it is typically later in Chicago. The extended forecast is not indicating any frost coming soon.
Tender plants can be protected from light freezes by covering them with sheets, plastic or boxes. When night temperatures begin dropping below 45 to 50 degrees, it is time to bring in any tropical plants that you are keeping outside. A gradual decline in temperatures over a period of time is best as the plants will acclimate to the cooling weather. You may want to move the tropical plants in for a night if there has been a long spell of warm weather and a sudden dramatic drop in temperature is predicted.
Use warm days to install lights
Warm fall days are great for installing holiday lights though most people do not think about installing them until after Thanksgiving. It is much easier to wrap branches with strings of lights on warm days in mid to late October versus cold days in late November or early December. Use LED lights to save on power and to use more strings on a circuit. Buy warm color white LED lights if you want to match the color of the commonly used white incandescent lights. Cool color LED white lights will have a blue cast to them. Wrap branches of your trees with strings of lights to accent the tree’s form.
You may be able to leave lights on your trees for a couple years to save time. I have had problems with squirrels chewing through the strings of lights left in trees so you will want to monitor them over the summer and remove them if you start seeing damage. As the tree grows the lights will tighten so they will need to be reinstalled. Be sure to use power cords that are rated for outdoor use.
Look for thirsty plants
Continue to monitor any plants you have installed over the last three years to see if they need supplemental water. Pay very close attention to the plants you installed this year as the dry conditions can more quickly damage them.
• Tim Johnson is director of horticulture at Chicago Botanic Garden, chicagobotanic.org.