Master Gardener Column by Jan Phipps
I admit to being a mulch evangelist. If you are a long-time reader of this column, you’ve seen me repeatedly write about using an organic mulch for weed control and preventing rapid changes in the temperature and moisture of the soil. I stand by that recommendation for most plants, however, there is some vegetation that grows better without being mulched, at least with an organic mulch.
Some of the drought-tolerant plants not only survive dry conditions but actually require them. High humidity, in both air and soil, contributes to root and stem rot. One key to determining which plants like it dry and which plants don’t is to discover from where they originated. Plants found growing in areas flush with leaf litter and other plants will prefer organic soils and mulches. However, plants springing from sandy or rocky, fast-draining sites will be happier with a mulch of pea gravel or sand.
Of course, a far easier way is to read the plant tag when purchasing a new plant. If it says, drought-tolerant, believe it with one caveat. It actually means “drought tolerant once it is established”. Most plants, even prairie plants need time to grow a deep root system before being able to survive a drought, so give them some supplemental water if rain isn’t adequate the first year. The exceptions are cacti, succulents, and yucca.
Generally, if a plant tolerates dry conditions, it also does well in sites that get hotter than the rest of your yard. For most of us, that is typically on the south side of the house or other buildings. For people living in town, it could be the strip of land between the sidewalk and the street, especially if it is treeless.
The following are some plants to try in your hot, dry spots. Vegetation with grey or silver fuzzy leaves grows well under these conditions. Try rose campion, lamb’s ear, Russian sage, yarrow, some of the artemisias, licorice plant, and dusty miller. Plants with succulent leaves like the sedums are another choice and don’t forget the ornamental grasses. Many of them do very well in hot, dry sites, especially the warm season grasses. Finally, some common bedding plants for those hot, dry areas are cleome, zinnias, cosmos, coreopsis, hollyhock, and gaillardia.
While you are planning what to plant this coming growing season, try some of these tough growers in your fast-draining, high-heat areas. A little trial and error will soon show you which can tolerate organic mulches, and which can’t.
This column is brought to you by the Edgar County Master Gardeners and Illinois Extension. If you have gardening questions, please call 217-465-8585 and leave a message. A Master Gardener will get back to you.