Developments in Tougher Turf

By Clarke, Graham

Graham Clarke looks at cultivars designed to cope with climate change

There has been plenty of talk about the changing climate and how it is going to affect gardeners, but little seems to be mentioned when it comes to the professional turf industry. Just how will our parks, designed landscapes, golf courses and sports fields cope with longer, hotter summers and reduced watering? And, on the flip side, will our public grass stand up to milder but wetter and possibly longer winters?

We need altogether tougher grasses that can withstand both drought and winter wet. and grass seed breeders have been gearing themselves up for this.

Sports Turf Research Institute (STRI) head of turfgrass biology Dr Andy Newell explains that the foundation for drought-tolerant grasses is already there. “Ryegrasses and fescues are relatively deep rooting,” he says. “This means that although they will turn brown in a period of prolonged dryness, they will nearly always recover. Red fescue and the so-called ‘hard and cheap’ fescues are certainly very good, unless you need the finest of lawns.”

Fescues, says Newell, are also suited to areas where it is impracticable to conduct a fertiliser regime.

Grass seed breeder Barenbrug UK is a key driver of the newer, tougher mixtures, and has launched a new strain to help groundsmen and greenkeepers successfully respond to the challenges of climatic and environmental change. BAR 10 with rhizomatous tall fescue (Festuca arundinacea, known as RTF) has been designed to provide users with a mixture that is capable of withstanding both drought and waterlogging together with good recovery and wear tolerance. The mixture, available now, is a blend of RTF, tufted tall fescue and heat-tolerant perennial ryegrass.

Barenbrug UK research and development manager Jayne Leyland believes BAR 10 with RTF will be the solution for overseeding from now on. “While coping with the drought issue was understandably the priority last summer, we must not forget that we suffer from other, equally damaging environmental pressures such as waterlogging, shade, disease, adverse temperatures and so on. In BAR 10 with RTF we have a mixture that can tolerate whatever the weather and other environmental stresses throw at it.”

Company trials have demonstrated that RTF has a wear tolerance similar to perennial ryegrass mixtures but, importantly, also has better recovery owing to its aggressive rhizomatous growth.

Four members of the so-called RTF Turf Group – Inturf. Lindum Turf, Q Lawns and Tillers Turf – are accredited growers of this turf in the UK and have been impressed with its good recovery after harvest. Tillers Turf managing director Tim Fell says: “The selfrepairing capability and fast establishment of RTF are seen as key attributes. Last summer it demonstrated how well it can cope with the drought, maintaining growth and colour even in the hottest and driest spells.”

Fell was the first grower to put down acreage of RTF in the UK. He adds: “It is an interesting species which produces underground stems (rhizomes) offering good recovery and tensile strength. Then there is the added benefit of incredibly fast establishment when laid as turf, which could be critical in terms of water conservation.

“Traditional tall fescue grasses clump together leaving bare spots and an uneven lawn, which means weeds can quickly take over. But RTF has the ability to repair itself filling these open areas with rhizomes.”

Lindum Turf managing director Stephen Fell agrees: “In addition to its rhizomes, RTF has deep roots (up to 1.5m) that enable it to withstand the vagaries of our changing climate, from drought to waterlogging. And its rapid germination ensures quick establishment of the new lawn. When overseeding an existing lawn, this fast germination means RTF competes successfully with the old turf, eliminating clumps and bare spots.”

Latest developments

Two new chewmgs fescues from Barenbrug are Barbirdie and Barswing. Leyland says: “Barbirdie performs well under close mowing regimes and offers consistently green colour all year round. Barswing, which is suitable for greens, tees and fairways, germinates well under cool soil temperatures and has superb shoot density. It also has outstanding resistance to a variety of diseases such as dollar spot and red thread.”

The company has also been conducting trials to test cultivars for minimum, maximum and optimum temperature germination. Leyland says: “With our unpredictable climate, we need to develop cultivars that germinate in cooler temperatures to extend the renovation window, and others for warm temperatures that can help with re-instatement following heat and drought damage.”

But according to Inturf joint managing director Stephen Edwards there are two other factors that make RTF special. “This is a highly promising grass. We have seen that it is everything Barenbrug has maintained and more. It performs well in shade and has a surprisingly good salt tolerance.” he says.

But he stresses that it is not just the grass seed mixture that determines whether turf is going to be drought-tolerant. “The condition of the topsoil is hugely Important,” he adds. “Customers are increasingly asking for turf that is not only supplied with good soil, but environmentally sound soil, and after considerable trials we are able to supply Premium Soil comprising 50 per cent recycled green compost. And if this is mixed with our water-retentive soil conditioner, TerraCottem. the grass will get off to the best possible start. The turf would even perform well if there was a drought in the first year.”

Mixture synergy

In separate STRI trials consistent results are being obtained from mixture synergy work. Visitors to the demonstration plots have seen the effect that one species or cultivar can have on another within a mixture. Eight Barenbrug mixtures, all with RTF as a component, were sown in October 2005 and have provided valuable data on the importance of synergy in mixture formulation.

DLF Trifolium has added Drought Master to its ProLandscape range. It takes advantage of DLF’s breeding of turf-type tall fescues to provide a fine-leaved alternative to ryegrass. Combined with sheep’s fescue Quatro, the tall fescue mix is recommended for turf where water supply is restricted and can also cope with waterlogging.

DLF representative Miranda Chambers says: “This tall fescue has a strongly veined upper leaf surface with a large, flat, mature leaf, short ligules, small hairy auricles and purple-red leaf sheaf. Growth is in tufts. It has very good resistance to heat, cold and drought, with good wear tolerance. It makes up 70 per cent of Drought Master.”

“Of course,” adds Newell, “if a landscape specifier is wanting a green sward even during a drought, they would do well to consider the grass-and-clover ecology lawns such as DLF’s Microclover.”

Most forage white clover is small leaved when regularly mown in a lawn but, according to DLF. Microclover persists and remains as a micro-leaved plant, evenly spread among the grasses. It is also a nitrogen generator in the lawn, meaning a reduced fertiliser regime can be implemented. Tests have shown that Microclover in a lawn mixture also has the effect of keeping many types of broad-leaved weeds away.

Green roofs are another way of reacting to and coping with climate change. Lindum Turf has been looking at the potential of green roofs for some years. Stephen Fell says: “Ever since the Stern Review we have all been thinking of ways to combat climate change, and green roof technology can go a long way to helping the environment, especially in large cities where there is little enough green space.”

Research at the University of Sheffield’s green roof centre has shown that mixtures of wildflowers, such as Lindum Wildflower, can have the same performance as traditional sedums and other green roof plants for reducing water run-off from roofs after heavy storms, but with the additional benefit of promoting biodiversity.

Two years ago, London’s mayor Ken LIVmgstone said: “Unlike other European cities such as Paris, Berlin and Venice, living roofs are not a common sight in our capital and we are missing major opportunities. The argument that living roofs will blight the lives of neighbours through overlooking misunderstands the very nature of cities and means we miss the opportunity to utilise attractive liveable space in a compact city.”

He is urging planning authorities to work closely with architects and designers to maximise the opportunities to develop these underused assets.

Tough mixture: RTF turf has deep roots and self-repairing capability and is able to tolerate both drought and waterlogging

“While coping with drought was the priority last summer, we must not forget that we suffer from other, equally damaging environmental pressures”

Jayne Leyland, research and development manager, Barenbrug UK

ENVIRONMENTAL IMPACT: OPERATION BUMBLEBEE

Managing grasslands for bumblebees is going to be crucial if we are to halt their decline.

One of the 20 bumblebee species previously found in the UK has disappeared entirely and three more are on the verge of extinction. Total bumblebee numbers have declined by more than 70 per cent in two decades due to the loss of suitable habitats.

Operation Bumbl\ebee is a joint pilot initiative pioneered by Syngenta Crop Protection UK and administered through the STRI. It is set to provide golf clubs with management techniques that will help to restore bumblebee populations on their courses.

The operation is based on the science from the five-year “Buzz Project” and was first set up to help restore bumblebee populations on farmland. The success of the project has led the work to be extended to golf. Syngenta representative Simon Elsworth says: “Bumblebees are nature’s pollinator and are in serious decline, and golf is a major land use covering over 150,000ha of the UK’s land area. Golf courses provide ideal locations because they are stable, little disturbed and normally support significant tracts of land out of play that, with management, could provide ideal habitat for bumblebees and other invertebrates.”

Four golf clubs have initially agreed to take part in a three- year trial: Haggs Castle in Glasgow; Worsley Golf Club in Lancashire; Fulford Heath in Worcestershire; and Bearwood Lakes in Berkshire.

Promoting biodiversity: green roofs can benefit from mixes such as Lindum Wildflower

Copyright Haymarket Business Publications Ltd. Mar 1, 2007

(c) 2007 Horticulture Week. Provided by ProQuest Information and Learning. All rights Reserved.