Rust Diseases on Home Lawns
(See other
lawn care information on our website
www. urbanext.uiuc.edu)
Editor’s note: Rust often appears on lawns
in late July, be prepared for it.
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 depletion 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 via air, water,
shoes, equipment,
and vegetative turf material (sod). Rust may weaken turfgrasses
and make them more susceptible to other problems.
Control rust through sound turf management. Begin by choosing
a quality turfgrass seed blend of several cultivars of the
species desired
for the site. Resistance to rust can vary according to the
race of the disease present. A diverse turf stand helps combat
rust
and numerous
other turf problems. Maintain lawns through sound watering,
mowing, and fertilizing. 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
over the
site and light penetration by pruning trees and shrubs in the
area
near
the lawn.
When rust occurs in late summer, improved growth conditions
of early fall often get lawns growing more vigorously and
the rust
fades away.
Early September is a key time for fertilization. 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 cultural practices described above.
June-July 2003: Herbs | "Pretty" Purple
Plants Can be Pesky Plants | Long
Term Planning Leads to Successful Gardening | Honey
Bees, Wasps and More | Rust Diseases
on Home Lawns |
