Lawn rust, peony and raspberry care

By John Fulton

[October 06, 2010]  Rust in lawns -- This past week, rust has paid us a return visit. As grass growth slows, rust is one of the lawn fungi we are dealing with. Rust appears as an orange or yellowish-orange powder (spores) on grass leaf blades, especially in late summer to early fall when the weather is dry. Rust typically develops on lawns growing very slowly. Overall, the turf may assume a yellow, red or brown appearance. Close examination will reveal the pustules, which easily rub off on your hand. Rust spores can easily be tracked into homes.

Low fertility -- in particular, nitrogen -- and low water availability slow down turf growth, allowing rust to develop. Seasons with excess rain may have rust outbreaks due to loss of available nitrogen. Cool nights with heavy dew and light, frequent rainfall add to the ideal conditions for rust to develop. Warm, cloudy, humid weather followed by hot, sunny weather also favors rust development on lawns. Kentucky bluegrass, perennial ryegrass and tall fescue are all affected, depending on cultivars. Rust spreads through air, water, shoes, equipment and sod. Rust may weaken turfgrasses and make them more susceptible to other problems.

Control rust through sound turf management. Begin by choosing a quality blend of turfgrass seed. Resistance to rust can vary according to the race of the disease present. Maintain lawns through sound watering, mowing and fertilizing. If you are watering, water early in the day so the grass dries quickly. Manage problem thatch. Increase vigor with an early fall nitrogen application, but don't overdo it. Check soil phosphorus and potassium levels through soil testing. Also assure good airflow and light penetration over the site by pruning trees and shrubs in the area near the lawn.

A change in the weather will make rust fade away.

Early September is a key time for fertilization. If you missed the early September timing, you can do a fertilizer application now. Use something with an even analysis or a winterizer. If conditions are dry, irrigation is also needed to increase the growth rate of the lawn. Fungicides are rarely suggested on home lawns for rust control. Focus on the listed cultural practices described above.

Fall care of peonies

Peonies are one of those "plant it and forget it" flowers. Many haven’t been bothered for over 50 years and are still going strong. As with most plants, crowding can occur, and the time to dig and divide is late September through October. Peonies do best in soils with a slightly acid to neutral pH. The best time to add lime, if needed, is when you dig the plants and replant them. Amend the soil when planting.

When dividing, make sure you leave buds on each piece you plan to plant. To allow for proper flowering, these buds should be no deeper than an inch when replanted. Mulching will help yearlong on any plant and peonies are no exception.

Pruning raspberries

To start with, remove all the dead, short and weak canes on raspberry plants. Thin the large remaining canes to 4 to 8 inches apart. Cut back the canes to 5-6 feet tall or, if no support is provided, 3-4 feet tall.

The canes that produced last year should be removed anytime after harvest or removed in the late fall. Canes are productive only one year, and the new growth will produce the next year's harvest.

The exception is the Heritage, or ever-bearing, raspberry, which produces two crops of berries, one in the fall and the second in late spring or early summer. These berries should have the canes removed after the late spring or early summer crop.

[By JOHN FULTON, University of Illinois Extension, Logan County]