Mowing a Wildflower Meadow: A Practical Guide

Background

Hay meadows by definition have to be mown; a meadow is a mown mead. Like a traditional hedge, a hay meadow is a landscape feature which is hugely beneficial to biodiversity, soil health and carbon capture - while also being man made. In prehistoric times animals like auroch and boar did this job - or a similar one - as they wandered through the landscape. It would have been a good deal less effective! For a start, they didn't know when to mow a wildflower meadow...

History  

Historically, hay making was by hand, of course, over several days. This meant that the exact timing of the cut was much more weather dependent than it is now. For lowland meadows it would have typically been from the from early July in southern England. The aim was a balance; to extract the most nutrition for winter fodder, while allowing seed to fall and maintaining the health of the meadow. 

Management varied according to local conditions and the required output. Floodplain meadows were highly valued; their rich soils meant the hay cut was typically in June. Upland meadows on more skeletal soils would have been mown much later. 

Why Mow Now?

Historically mowing was principally to produce hay, of course. These days farming systems have changed dramatically; this has been the single biggest reason behind the collapse of meadow acreage in the UK. Although the tide is turning, the fields around us in Somerset are typical. The grass is cut for silage repeatedly over the summer, sprayed off every few years and resown. Most people don't principally have wildflower meadows for their hay production, but rather for their aesthetic and ecological value. So why cut them in summer?

There are four principal reasons:

To stop vegetative succession

Left to its own devices, a meadow will become scrub and then broadleaved woodland. A regular cutting regime will stop your meadow being taken over by blackthorn and hawthorn, then birch and willow, then oak and beech. 

To reduce nutrient levels

This has become very important. Soils are becoming more nutrient rich thanks to higher nitrogen levels in the environment. This means more vigorous opportunistic species like nettle crowd out many wildflowers. Grasses, particularly coarser grasses, will do the same. Many of us are stuck with agricultural or horticultural grass cultivars too, which will be even more aggressive. This is bad news. Although all native species have biodiversity value you can have too much of a particular species. You want the most floral diversity you can get for your meadow, for enhanced biodiversity and aesthetics. By cutting and collecting the arisings you are taking nutrients out of the system and encouraging just this.

To reduce grass dominance

In addition to crowding out wildflower species, grasses will fall over and create a dense mulch if left unmanaged. Only the most vigorous wildflower species will make their way through it, and as it rots it will increase soil fertility. 

To Manage Volunteer weeds

Cutting will of course manage any annual weeds which might take over in a new meadow. If you are looking at a field of thistles, cut them before they set seed! Nearly all meadow species are perennial and have basal rosettes, and you won't do them any harm by cutting at any time of year. 

When do I Cut My Meadow?

 

The first thing to say is that cutting should be done early rather than late - although see the section below about drought. People often prevaricate as some late species, notably knapweed, are still flowering at this point. It's really important to steel yourself and do it, notwithstanding. If you leave it too long all is lost; the grass will get long and rank, then go over when it gets wet, at which point cutting it is impossible.

Having said that, if you have Yellow Rattle in your meadow, as an annual, it's really important to allow it to set seed, from late June. 

I have seen advice online that you should leave cutting until September or even October because of the damage you do to invertebrate populations and the availability of seed. Well, yes - but very quickly you will be looking at just coarse grasses. A useful habitat in themselves, but probably not what you want.

You can mitigate this effect of cutting by leaving some margins around the meadow to develop into tussocky grassland. These will provide shade and over-wintering sites for invertebrates and nesting opportunities for voles and bumblebees. Cut these sections in rotation every three years to prevent the establishment of scrub.

Try to change the date of mowing, or - even better - mow your meadow area in sections over a few weeks. This will encourage both early flowering species and the later flowers. An obvious symptom of a meadow cut too late is the sea of knapweed which will confront you, and the disappearance of spring flowering species.

When is "early" and when is "late"? This depends on your site. Current conventional wisdom is that the window is around late July to mid August for downland meadows in the south. Upland meadows around two weeks later and Floodplain Meadow two weeks earlier. Some experts are now arguing that because of the effects of climate change you should cut your meadow earlier. 

If practical, the optimum answer is to cut your meadow area in sections - the mosaic approach. The ecologists all say this. The problem is you're often dependent on a contractor, or a farmer, or machinery hire. If you're not then absolutely, cut over a two to four week period, and vary which bit you're doing then.

This is only a guide. This year I mowed a section of our meadows in mid July, because it has a very nice covering of Cowslips and I didn't like the progress the grass was making. I also cut a section which was getting knapweed heavy.

How Do I Cut My Meadow?

Have a look at the section on small meadows below. For these, your options are either manual - scything - or finding a piece of kit to buy or hire which cuts the meadow efficiently and doesn't mulch it. This could be an automatic scythe, for example.

You're going to end up doing the work yourself or paying someone to. I used to love scything, but I find it a bit of an effort these days. It's the best option, but sometimes impractical. Think too about what you're going to do with the arisings.

For larger meadows, find a contractor or farmer who will cut and bale. In reality, most farmers won't take your hay - lucky you if they will. They generally want it cut earlier than you do, and they'll tell you its too stalky and nutrient poor. If you end up with lots of bales, find a corner of a field to leave them to rot down. If you can find a local site which needs green hay that's the best solution - donate your hay! 

Drought

The increasingly hot dry weather we're experiencing complicates the timing of the cut. It can't do soil structure and microflora any good to be exposed to much higher temperatures as a result of taking a hay cut. One of species rich grassland's superpowers is to improve just this.

Ditto the various invertebrates and small mammals, which will have been much cooler in taller vegetation. And a cut seems less important, given that the grasses have long ago gone into survival mode; you're effectively cutting standing hay. 

I've yet to see much work on this, but in the meantime I'm trying to use common sense. If in drought conditions, I'm carrying on cutting areas with a lot of grass in the usual window. I'm leaving more uncut areas around the meadow, typically at the base of hedges, and I'm leaving more grass on than I would do normally - at least a couple of inches. As for more florally diverse sections with less grass, on more skeletal soils, leave them a bit longer.  

It's also worth pointing out that meadow species are generally incredibly resilient. Grassland is much less damaged than woodland by wildfires, for example. Another meadow superpower! 

After Cutting

It's REALLY important that you pick up the arisings whenever you cut the meadow. Why? Firstly, to reduce the fertility of the site. Wildflowers don't respond to higher nutrient levels like grasses do, and this is a good way to help. Secondly, hay lying on the ground will act as a mulch and stop shyer wildflowers growing through it. 

Once you've cut and removed the hay, either run stock into the aftermath or cut it closer. It's not as important to collect these cuttings, but helpful if you can. Keep the meadow occasionally cut or grazed over the autumn and winter, stopping in early March before the Rattle seedlings germinate. This didn't use to be as important as it is now. Don't worry about cutting it too short unless it's hot, in which case cut it to an inch. 

You can either mob graze it if you have animals or graze it at low densities with set stock.

Small Meadows

The theory is pretty clear, but what does it mean in practical terms for managing a small meadow? If your meadow is above something like 20 acres it's pretty simple. Chances are you'll be able to find a local contractor who will cut, bale and even remove the hay for you. You may even be able to sell someone the seed from it. Happy days.

Councils and contractors are increasingly investing in specialist cut and collect machinery, which is fantastic if you have multiple smaller sites to cut, but super expensive. 

For us smaller landowners it's trickier. Contractors aren't interested in our two acres of meadows - why on earth should they be? And the last thing I want on my land is an enthusiastic teenager in a massive tractor careering around ponds and fruit trees!

Originally I used to scythe our meadows, which I recommend before you become old and knackered. I love my Austrian scythe, and it's definitely the best option for smaller meadow areas like ours. It's extraordinary to think that even lawns like those at Versailles were once cut this way. Richard Brown, ex Emorsgate Seeds, is the doyenne of the scythe world - look him up.

More recently though, I used to hire kit. Sorry Richard, I've let you down. A power scythe (or sickle-bar mower) is a good shout; these are contemporary versions of the old Allen Scythe. They're relatively light and manoeuvre well, but they don't cope with rough ground very well, so plant hire business have stopped offering them in favour of flail mowers. 

I find these difficult. They're awkward, clunky and hard work to handle, difficult to control and imprecise. They're poorly designed and prone to breaking down. Hmm.

I have now bought a Weibang wheeled strimmer, which works very well. To start with, having your own kit is a significant advantage to hiring stuff. It means you can stagger your cut across a month of work, which is optimal in terms of floral diversity. 

Second off, unless you have larger areas, the cutting deck is big enough but the cut is precise and the machine easy to use. Thirdly, the payback on a machine like this is around 7 years if the alternative is hiring. Not bad.

After cutting you MUST collect. This means you can't use a mulching mower, incidentally. For smaller sites this generally means raking arisings by hand. This is a bore, but helps spread seed. Don't feel you have to leave the hay lying around for days for the seed to drop from it; just raking it will do the trick. 

What do you do with all this hay? Even if you have a lot of Yellow Rattle you'll have a good volume. Farmers generally won't touch hay from sites like yours. They don't know what's in there, the hay is too stalky, the volumes too small. We compost some of it and rake it into our surrounding hedges, where it acts as a mulch to suppress weeds and grass. It's a great feedstock for biodigestors, so I know of some urban projects which dispose of hay this way. Green hay is also a rich - and free! - seed source, of course - you can use it to strew over neighbouring sites too.