The drought from 2012 combined with our fall football schedule left our field with less than 25% cover through the center high traffic area, so we dormant-seeded an 80/20 mix of Kentucky bluegrass/perennial ryegrass in early November, along with aggressive aerifying. We saw a little perennial ryegrass germination in the spring but by summer we were still thin and now we are faced with weeds and weak grass to start the fall season. Our other soccer/football fields and some multiple use football/baseball fields that are not as worn out but still need overseeding to fill in bare areas. We do not want to use the bluegrass/ryegrass mix again and have been considering turf type tall fescue. Do you think it’s a good choice and what about perennial ryegrass?
Lafayette, IN
My answer to this question has changed over the years since tall fescue first came on the scene as a suitable grass for home lawns. In the past because tall fescue is a bunch grass we would caution users to not overseed existing stands of Kentucky bluegrass or perennial ryegrass with tall fescue because the resulting sward of grass could potentially have clumps of undesirable tall fescue sparsely spread throughout the turf area. In home lawns this would be unattractive and in some sports like soccer and baseball it could affect ball roll. In fact, that risk of tall fescue clumping does still exist in theory and occasionally it may happen.
However, after several years of watching how many sports turf managers use tall fescue as an overseeding strategy and after watching their many successes I have completely changed my mind on overseeding with tall fescue to improve sparsely turfed fields where bluegrass and ryegrass have not performed well. This has been especially true on fields where irrigation is inadequate or substantially reduced during drought regulations.
I am a big fan of Kentucky bluegrass for moderate traffic situations where the grass has sufficient time to recover and fill back in to 100% cover. But since bluegrass is so slow to germinate it has left me very unhappy unless I allow nearly a full growing season to let the seedlings mature, tiller and put on rhizome growth. With perennial ryegrass and tall fescue you can expect the bare soil areas to cover twice as fast as Kentucky bluegrass and this is a much better fit for our world of sports turf that needs grass yesterday.
For many sporting fields where you are simply trying to maintain cover the canopy compatibility of Kentucky bluegrass, perennial ryegrass, and tall fescue is not an issue and players and coaches never question the type of grass, but they do notice when bare soil is showing. We also know that continued overseeding with perennial ryegrass will maintain better turf cover but it can, in just a few seasons, shift the turfgrass stand so that it is mostly ryegrass. If you are constantly fighting drought or disease then the ryegrass suffers.
Tall fescue will germinate and mature much faster than Kentucky bluegrass but slightly slower than perennial ryegrass so it fits nicely into the category of a relatively speedy grass that at least shows some type of pay back in turf cover for your time and dollar investment. I seed a lot of my chronically thin fields with a 50/50 mix of perennial ryegrass and tall fescue for the simple reason that it gives more cover the following year. If I see the tall fescue starting to take hold after a year or two then I may switch to overseeding just with tall fescue. Once I start with the tall fescue I like to give it about 3 years of overseeding as needed to give it a chance to prove itself.
The take home message here is that if you are happy with the turf cover on your field, then don’t switch to tall fescue just because someone tells you it is a more drought tolerant grass. On the other hand if bluegrass is not performing the way you want, and dry conditions are part of your turf decline problem, then repeated overseeding with tall fescue may leave you with more grass cover on the field throughout the playing season and a better window of opportunity to establish grass because of faster germination.
In my world turf cover that results in better playability always trumps any potential problem I may have with clumpy turf. In regions where tall fescue grows well the odds are good that tall fescue can help some of your problem fields. It’s just not that much of a gamble any more with tall fescue once you start to see more green each year.