By Jan Phipps
I saw a lot of pictures of Shasta daisies over the summer on both social media and professional gardening sites. They are the classic summer flower. Leucanthemem x superbum, the Latin name, was developed by Luther Burbank and named for Mount Shasta because its petals were the color of snow.
Most varieties of Shasta daisy are cold hardy and do fine in our growing zone given the right conditions. They love full sun, all day long. If they get some partial shade, they will still bloom, but not as abundant.
They prefer moist, well-drained soil enriched with organic matter. Amend the soil with compost when planting, then top dress with more every spring, being careful not to cover the crown. Shasta daisies are prone to root rot in slow draining sites with lots of clay. If that is a problem for you, try growing them in raised beds.
Shastas spread by underground rhizomes that extend out from the main plant. Over two or three years the original plant will be gone, at which time you need to dig up and replant the satellite daisies, or the following year they may also be gone. It seems like a lot of work, but it gives you the opportunity to once again enrich the soil with organic matter.
Plan to deadhead spent flowers as they die to encourage a longer bloom season. You can cut the top growth back to the ground after a hard freeze in the fall or wait until early spring cleanup the next year.
Speaking of fall or spring cleanup, it is time for the opinions to start flooding in. Is it better to remove all summer growth leaving a tidy, flat surface for winter? Or, is it better to leave everything in place until late winter or early spring?
The former helps with disease control and is recommended for vegetable gardens for that reason. Also, some gardeners like that tidy, “put to bed” look.
Leaving garden debris in the garden over winter also has some benefits. It provides cover for various stages of beneficial insects. It supplies an insulating layer that helps prevent frost heaving, and traps additional leaves for even more winter protection. Perennials with rigid stems or an architectural form also supply winter interest in the landscape. You are the gardener, and you get to decide which works best for you.
If you have questions about fall cleanup, call the Illinois Extension Master Gardener Helpline at 217-465-8585 and leave a message. We will return your call.