Learning to Grow: Ask the Master Gardener, Jody Lay

It’s that time of year again. Time to mound leaves around your roses, prune your paniculata hydrangea, and time for another round of “Ask the Master Gardener.”

What can I divide and transplant in the fall?

You can divide, transplant and plant just about anything in the fall. You just have to remember to water, so the plant has enough moisture to get through the winter months. Be careful with spring bloomers; peonies and lilacs will most likely not bloom after transplanting this late in the year. Typically, spring-blooming plants should be transplanted right after they bloom. I trim back my irises, lilies and hostas, so fall is an excellent time to dig them up and divide.

Should I trim my mums after they bloom?

Mums are not reliably hardy in our climate, but if you find the ideal, protected location with perfect drainage and mulch them, they might come back. You don’t have to trim them, but they turn dark after a hard frost, so I cut them back.

Why didn’t my oakleaf hydrangea bloom, and can I prune it?

Oakleaf hydrangeas are my favorite because they like shade and tolerate acidic soils. That being said, they don’t like heat, so don’t plant them too close to a foundation, driveway or anything that radiates heat. Avoid areas where they get too much sun. They also prefer well-drained soil, so – if you have clay or dense soil – they will yellow or not perform. The same goes for alkaline soils. They rarely need pruning, but – if you need to shape them – do it right after blooming because buds form on new growth.

We took down our ash trees. What are good replacements?

You need to consider what is most important to you. I chose based on aesthetics or native species to encourage our natural habitat. Native trees, such as oaks, are a haven for our local wildlife and increase your chances of success. I planted a fringe tree last year because of its compact size and dainty flowers, and because it's native to Illinois. You can find more information on the University of Illinois Extension's website at http://extension.illinois.edu/treeselect/index.cfm. You'll find information including growth rates, growing tips and helpful tips on selecting the appropriate tree for your yard.

We’re first-time home-buyers and want to establish a lush lawn. Do you recommend an irrigation system?

That is a matter of preference, as it does take a regular watering schedule to keep your lawn lush. If you don’t have the time or patience to get out there every day and water consistently, it can be difficult to establish a nice lawn. An irrigation system will maintain the aesthetics of your lawn, but many studies show the grass never establishes a deep root system to reach its own water supply. Grass needs about 1 inch of rain a week. In my opinion, to really get a beautiful lawn, it’s in the seed you select; tall fescue and Kentucky bluegrass have deeper root systems and stay green into the drought of summer.

• Jody Lay is a University of Illinois Extension master gardener for Kane County. The “Learning to Grow” column runs weekly during warmer months. Call the extension office at 630-584-6166 for more information.