Help in identifying and eliminating an undesirable grass in my lawn

Asked April 27, 2018, 5:45 PM EDT

My back yard was seeded with Blue grass many years ago. It has been overtaken by some other type of grass. The undesirable grass is thin bladed, shallow rooted and does not take foot traffic (such as badminton for instance). Because of the shallow roots, it dries out easily and turns brown easily in the summer - but it comes back the next season. Is there a process at the U where I could bring or send a sample for identification or is there another place to go. I have fought this thing for years and am about ready to kill the back lawn off and turn it over and re-sod!!!

Dakota County Minnesota lawn weed horticulture lawn and turf

1 Response

Here is our sample id process. https://pdc.umn.edu/submit-sample

A first question would be: Does the EXISTING lawn consist of any undesirable or weedy grasses? If so, sod removal is likely to leave behind enough of the old grass that it will grow back - along with the new sod. If undesirable or weedy PERENNIAL grasses (bermudagrass, quackgrass, kikuyagrass, etc) are growing in the current lawn, then the use of glyphosate (Roundup) to control them prior to resodding is essential.

Obtaining control with Roundup/glyphosate it is best to NOT mow the grass "short" before applying the herbicide (the more leaf area, the better the control will be). Also, complete kill will take more than "a few days". The best results are obtained by making two applications of Roundup, about 10-14 days apart. Total kill of the existing grass may take, in other words, about 3-4 weeks.

For lawn renovation using sod, the general recommendation is to kill the existing sod and remove (using a sod cutter) a very thin layer of the surface. This leaves most of the topsoil intact and provides a good rooting medium for the new sod.

For renovation using SEED, killing the old sod followed by heavy aeration (coring) - and then followed by overseeding - is an acceptable and rapid way to renovate an old lawn. In this scenario, the dead turf is left intact - where it acts as a mulch and seedbed of sorts for the new seed.

Refer to this fact sheet for additional information on lawn renovation:
http://www.ext.colostate.edu/pubs/garden/07241.html