Art in the garden: Late summer is a good time to plant perennials

As summer winds down and temperatures become less intense, you may be tempted to make some changes in your landscape. You may want to add new plants to fill gaps or correct planting mistakes.

But which plants are appropriate to move or plant now and which are best left to next season's task list?

Plants planted at the end of summer enter a hospitable environment due to more reliable rainfalls and lower, less hostile temperatures.

Successful planting depends on a plant's roots. Specimens with robust root systems will settle in quickly, benefiting from both the nutrient-gathering and anchoring capabilities of their underground parts. If you choose a plant at your local garden center that is pot-bound, be sure to loosen its roots and spread them evenly in the plant's new home.

Before you head out to your garden or your local nursery, keep the following guidelines in mind.

Container-grown plantsMany perennials are grown from tiny plugs that reach salable size while growing in a pot. Generally, these container-grown plants are excellent candidates for late summer and fall planting in your garden. Divisions of mature plants and transplantsIt's usually best to divide plants shortly after they have finished flowering. Late summer is a great time to divide and move day lilies, Coreopis, Shasta daisies, and many other perennials. And although peonies grace our gardens with their beautiful blooms in spring, fall is the traditional time to relocate these plants too.Plants suffering in their current locationsGardening is often about experimentation. If a plant has failed to thrive where it was first planted, it may simply require a change in venue. A plant that exhibited sparse bloom may need more sun, or one that suffered from yellowing foliage may prefer better drainage. Moving the plants to new homes now will give them time to build the stamina required to survive the winter. Make sure when you dig plants to leave a generous amount of soil around the plant's roots to minimize root damage.Shopping for plants at the end of the summerFollow the same rules of choosing healthy plants at the end of the summer as you do in spring. Look for healthy, robust plants free from disease and pests. Don't worry if a few leaves are less than perfect #8212; summer's heat takes it toll on most plants, but be careful of floppy or spindly plants.Ornamental grassesGrasses with the largest root systems are the best candidates for late season planting. It is wise to plant ornamental grasses by the end of September if possible. This will give them time to settle in before the ground freezes. If you plant them later than this, apply a thick layer of mulch after planting.Ground coversBecause much of a plant's fall growth occurs in its roots, fall is a fine time to plant ground covers. Cooler temperatures and ample rainfall help their roots establish, giving them a head start come spring.EvergreensHigh temperatures are stressful to many evergreens, so these plants will be particularly responsive to cool weather planting. Apply an anti-desiccant, like Wilt Stop, to protect newly planted evergreens from drying winter winds.The biggest advantage to late-season planting may be the shortcomings of this year's garden are fresh in our minds. We don't need to rely on our memories to recall the need for color or where the gaps were. Take some time now to assess your landscape, add or move some perennials, and reap the rewards next spring.#376;Diana Stoll is a horticulturist and the retail manager at The Planter's Palette, 28W571 Roosevelt Road, Winfield. Call (630) 293-1040 or visit planterspalette.com. 21701556ItÂ’s best to divide mature plants or transplant right after the plant is finished flowering.