Rust Disease in Lawns

Our turf grasses are prey to numerous disease and pest infestations. One fungal disease called rust, occurs almost exclusively on Kentucky bluegrass and perennial ryegrass.  Although it is mostly a cosmetic issue, the easily dislodged orange spores can be a nuisance by covering shoes, pets and lawn equipment with a rusty residue.

Rust infected grass looks like it has a yellowish-orange hue. When grass blades are inspected closely, they will be coated with yellowish-brown to orange-red spores or dust and can be easily rubbed off with a finger. These spores, carried by the wind, shoes or equipment, spread the disease to other areas during the growing season.

Outbreaks of this disease are most common in late summer and early fall.  Low fertility (in particular nitrogen) and low water availability slow down turf growth allowing rust to develop. Formation of the spores also often occurs during seasons with excess rain which can lead to depletion of available nitrogen. Warm, cloudy, humid conditions followed by bright hot sun also contribute to the formation of rust spores.  Rust outbreaks require moderate temperatures (50 to 60 degrees F) and long evening dew periods (more than 10 hours).

Rust can be managed with attention to plant nutrition and regular mowing habits.  Apply small amounts of nitrogen fertilizer (two tenths to half a pound per 1,000 square feet) in chronic trouble spots (shaded and possible compacted areas) to help control the disease.  The nitrogen will promote leaf growth and allow for regular mowing, which helps the turf outgrow rust’s rather slow infection cycle.  Avoiding irrigation during the early evening will help limit disease spread by lessening the chance of extended dew periods.  It also never hurts to have a soil test done, paying attention to phosphorus and potassium levels.

When cultural practices fail to quell an outbreak, a single application of a fungicide can be used.  For the best result it is recommended that a professional lawn care service be used.

As always, Happy Gardening!

More information about gardening and related subjects can be found online. The Purdue University Cooperative Extension Service can be reached at 499-6334 in LaGrange Co., 636-2111 in Noble Co., 925-2562 in DeKalb Co. and 668-1000 in Steuben Co.

Winter Windowsill Herbs

  by Karen Weiland, Advanced Master Gardener     Even though our gardens are nestled beneath a blanket of snow, enjoying their winter nap, we can still enjoy a little indoor windowsill gardening and the taste of fresh herbs right now. Herbs are plants that are used whole or in part for their flavor.  Cooking …

Read More >

Recycle Your Christmas Tree

  by Karen Weiland, Advanced Master Gardener     Don’t know what to do with that Christmas tree?  Recycle it!  If you have used a live tree this Christmas, take the time to give it another use.  Live trees are biodegradable, which means they can be easily reused or recycled. Most Counties have free drop-off …

Read More >

Hold The Salt Please

  by Karen Weiland, Advanced Master Gardener     Too much salt in a person’s diet can cause problems. Here in our northern climate the same can be true for plants located near sidewalks and roadways. While they all set out to do the same job, some of the deicing materials on the market today …

Read More >

Get your official copy of our

Destination Guide

Request Printed Guide

View E-Guide

Stay informed and sign up for the

Shipshe E-Newsletter

  • This field is for validation purposes and should be left unchanged.