Welcome to the latest issue of the Home Lawn Care Newsletter from UMN Turfgrass Science! We will provide up-to-date information to address all your lawn care tasks at the times when you need to know.
August 15, 2023: Issue 14
When to seed or overseed your lawn
In Minnesota, August 15 to September 15 is typically the ideal time for starting or making improvements to a lawn when it comes to seeding. It’s best to remove perennial weeds before seeding to give space for your grasses to fill in. Read and follow label instructions for the amount of time to delay seeding after any post-emergent herbicides you may have applied; this re-plant window may be immediate or several weeks. Refer to the articles below for seeding, soil sampling, and best timing information for all lawn care practices. Keep in mind that exceptions may be necessary; for example, when seeding turf-type tall fescue, it is best to seed before Labor Day because this species can suffer damage if the plants are too young going into winter.
Seeding and sodding home lawns from UMN Extension
How to sample lawn and gardens from UMN Soil Testing Lab
Lawn care calendar from UMN Extension
Renovating a lawn for sustainability from UMN Extension
Mix it up to tolerate weather and soil conditions
Planting a seed mixture of multiple turfgrass species means you’ll have the best chance of seed establishment and long-term cover across the variable conditions within your lawn. The last three years of drought, heat, and winter stresses have reinforced the importance of using seed mixtures rather than a single species of seed in lawns. Some species are better adapted to stresses than others. For example, among the fine fescues (strong and slender creeping red fescues, hard fescue, Chewings fescue, and sheep fescue) there are differences in shade tolerance (strong and Chewings are the best), performance along the curb or roadside (slender is the best), or drought (hard is the best).
Planting a turf-type tall fescue mixture with some Kentucky bluegrass provides very good drought tolerance, more color during dormancy periods, and a lawn that fills in damaged spots well, compared to planting either of these grasses alone. Sometimes mixtures aren’t all that useful - adding high amounts of perennial ryegrass to a seed mixture will give you quick germination and growth, but poor cold tolerance, and more susceptibility to disease.
Planting and maintaining a fine fescue lawn from UMN Extension
Fine fescues – understanding the differences from Purdue University
Seeding your lawn this fall - Part 2 from UMN Turfgrass Science
Can we use tall fescue lawns in Minnesota? from UMN Turfgrass Science
Fine fescues in minimal to no-mow areas from Purdue University
Tips for purchasing quality grass seed
The turfgrass varieties we plant in our lawns are perennials that we want to persist for years or decades. So why not invest in higher quality cultivars or species that are better adapted to your growing environment? Through collaboration with other turfgrass breeders and scientists, cultivars and species are continuously regionally tested prior to their release to ensure they are well adapted for the local climate.
Despite being price friendly, grass seed sold in big box stores may not be the best adapted for your purpose. These may be more popular varieties that produce a lot of seed, resulting in a lower cost to the consumer, even though they aren’t very good for use as lawns. You may also find high levels of inert matter, unidentified varieties of seed (labeled as VNS or variety not stated) and weed seeds in the mixes.
Some seed products have coatings with fungicide, root stimulators, microorganisms, or protective barriers to help seeds retain moisture. There may be some value for some of these technologies, though little has been confirmed by research; nevertheless, in most cases they are not needed.
Refine your seed search to companies that specialize in seed varieties, mixes and blends that are known to be successful in your region. For example, if you need a salt- and drought-tolerant seed mix, look for a blend that is known to have those qualities, or species and cultivars that are adapted for these conditions. When you are shopping for seed, check the label to see that there are no weed seeds, unidentified seed varieties, and little inert matter. Good sources for lawn seed might be feed stores, independent lawn and garden establishments, or stand-alone seed companies.
The publications listed below provide variety recommendations for specific situations including those that have rated highly across the scientific trials. You can also do your own research by searching the UMN turfgrass science cultivar results page or the National Turfgrass Evaluation Program database.
Finding the right grass seed from UMN Turfgrass Science
Purchasing turfgrass seed from UMN Turfgrass Science
Turfgrass seed and seed mixes from Penn State Extension
Purchasing quality grass seed for your lawn from Purdue University
National Turfgrass Evaluation Program searchable database
Turfgrass cultivar evaluation results from UMN Turfgrass Science
Research highlight
One of the toughest sites in Minnesota to grow turfgrass is along a roadside. These sites are hot, dry, affected by road salt, and rarely have good soils. In addition, the most care they might get is some occasional mowing. The UMN Turfgrass Science program has been funded by the Local Road Research Board and the Minnesota Department of Transportation to conduct a series of projects trying to identify the best grasses to use on these difficult sites. Recently, Dominic Christensen, who received his Masters degree from UMN, showed that the roadside seed mixtures perform increasingly better as more species are added to the mixture.
Events
We will be at these events to answer questions on smart irrigation and lawn care as part of our collaboration with the Metropolitan Council.
- Minnesota State Fair in the CFANS wing (southwest hall) of the Agriculture Horticulture building, August 23 - September 4 from 9 a.m. - 9 p.m.
- Brown's Creek Watershed District Community Event in Stillwater, MN on Saturday, September 16 from 10 a.m. - 1 p.m.
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We provide research updates, lawn care tips, info about field days, and more at @UMNTurf.