Here's the article I wrote for the summer edition of Chatterbox.
At this time of year, grass really comes into its own. I’m not talking about mown grass, though admittedly it’s a great time for picnics on lawns. I mean grass left to grow to its full potential, with graceful, nodding flower and seed heads of wondrous texture and variety. Many of us are noticing more areas left unmown for part of the summer, as people respond to “No Mow
May” and other calls to do our bit to try to reverse the declines in nature. After trying unsuccessfully to think of a suitable slogan for extending non-mowing time, I was delighted to see a tweet from Plantlife mentioning “Let it bloom June” and “Knee high July!” You might have seen that Ketton Green Spaces Group is trialling leaving parts of Ketton Cemetery, Churchyard and Hall Close unmown till August. So why is leaving grass to grow longer beneficial for nature?
The first reason is not to do with the grasses themselves, but the other plants – the ones we call wildflowers - that grow amongst them. Many of these are a food source for nectar and pollen eating insects. Pollinators provide a valuable service not only to wild plants but to agriculture, but many species are decreasing in numbers. In the UK, the populations of a third of our bee and hoverfly species have decreased since 1980. 31% of our butterfly species are classed as “threatened.” And there are many other less “celebrity” pollinators: 1500 species of insects pollinate plants in the UK, including many flies and beetles. Wildflowers which provide food to all of these may well be already present in the grass sward (except where they’ve been killed off in the quest for a mono-culture lawn), but they don’t get much chance to flower if continually cut.
Nectar and pollen sources aren’t the only reasons to mow less. Many insects which feed on these as adults, eat something totally different when they’re juveniles, i.e. larvae (caterpillars, grubs etc) or nymphs. And they’re often very specific in what they eat. For example, Common Blue butterfly caterpillars mainly eat bird’s-foot trefoil leaves: a beautiful little yellow-flowered plant that might pop up if you leave an area unmown. As for grasses themselves, many caterpillars eat the leaves of common ones often found in no-mow areas. Our local caterpillars of Marbled White, Meadow Brown, Ringlet, Speckled Wood, Wall, Small Skipper and Large Skipper butterflies all eat Yorkshire Fog and Cock’s Foot grass as one of their main foods. I sometimes think insect larvae are rather overlooked in the conversation about reversing insect decline. Although some garden plants from far flung places can be great nectar sources (in my garden, Argentinian verbena and Californian poppies attract clouds of pollinators), we shouldn’t forget about the needs of the rest of the insect life cycle. Without larvae, you’ll get no adults. Native plants that larvae need may be in short grass, but regular cutting means not enough leafy food (and it’s hazardous for caterpillars that can’t fly out of the way!)
Of course, if we didn’t cut them at all, grassy areas would eventually turn into a different habitat altogether. Wide expanses of grassland are rarely natural in this country: without cutting or grazing, scrub, then woodland, starts to grow. These are valuable habitats, but they’re not usually the aim in these areas. Historically, meadows have been cut once or twice a year. As a side effect of removing the hay to feed livestock, soil fertility gradually decreased each time the cut plants were removed. This led to better conditions for wildflowers, which tend to be outcompeted by grasses in more nutrient rich soils. A native plant called Yellow Rattle also helps supress grass growth by stealing water and nutrients from the grass roots. Ketton Green Spaces Group have managed to establish this plant under the new orchard in Hall Close.
As for the visual impact of leaving grassy areas to grow longer, I know that some find it “messy,” but once you’ve experienced the buzz of giving homes to all that wildlife, might this start to change? Besides, the more I look at grass flowers the more I think they’re beautiful: structural, multi-textured and varied. And of course, the wildflowers living among them are beautiful. There have been quite a few orchids popping up in unmown areas across Ketton, including the fabulous bee orchids. Mowing edge strips and mowing paths through longer areas can emphasise that the other bits have been left long by choice. If you have an adjustable mower, even just raising the mowing height can reap benefits, as can adding some wildflower seed. (See the article in this issue by Ketton Seed Swap – they’re giving out free packets of wildflower seeds for lawns soon). There’s still room for short grass to run around on, and you can mow the longer areas as normal in autumn through to early spring.
In roadside verges and amenity areas, time of cut can be tailored to the needs of both wildlife and people. Ketton Parish council have been working with KGSG on the mowing plans for the cemetery, churchyard and new orchard, and they also leave the verge along the Luffenham road uncut ‘til late summer, apart from a strip right next to the road. Removing the cuttings is often a challenge, so when the new orchard meadow, churchyard and cemetery are cut, we’ll need volunteers to rake up the cuttings. Look out for details on the “Get involved” section of our website https://kettongreen.wixsite.com/kett. Also on our website are the surveys we’ve done on these areas so far (see Projects - Surveys). Do let us know your thoughts or wildlife sightings via our facebook page @kettongreenspaces or twitter @GreenKetton .
Addendum to the original article: of course, not all insect larvae eat leaves - depending on the species, other food sources include dead wood, other invertebrates, dung, pollen... The point is that they often eat something different from the adults, so it's important to understand that when trying to provide good habitat for them.
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