Patch-Hay Grazing – Just Another of Many Ways to Create Habitat Heterogeneity

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Managing grasslands for biological diversity and resilience depends a lot on habitat heterogeneity. Every plant and animal in the prairie has its own needs and preferences related to factors like vegetation height and density, diversity of blooming flowers, the amount of exposed bare ground, and many others. To provide for all those needs, we have to manage in a way that provides all those habitat types.

Even more, we want to manage so that those various habitat types occur in different places each year in a kind of shifting mosaic of habitat patches. That allows mobile creatures to move to where they want to live, hunt, forage, mate, etc. It also allows plants to experience the growth conditions they like best at least every few years. As a result, no species consistently wins or loses and everybody stays in the game (persists in the prairie).

Sedge wrens (left) and upland sandpipers (right) need very different habitat structure for nesting. If you want both birds to nest in the same prairie, you need patches of tall/dense vegetation for sedge wrens and large areas of short vegetation for upland sandpipers.
Entire-leaf rosinweed (left) does well in prairies that haven’t been burned or grazed recently but daisy fleabane (right) is a biennial that does best after grazing or another treatment temporarily weakens dominant perennial plants. Consistent management in any particular place will likely eliminate one of these species over time.

There are lots of effective ways to create this kind of shifting mosaic and support a strong diversity of plants and animals (and other organisms). Foundationally, it just requires managers to split a prairie into multiple patches each year and make sure that each patch is both different from its neighbors and different than it was the previous year. Mowing, burning, and grazing are all ways to manipulate habitat structure and growing conditions.

All of those treatments can be applied at any time throughout the year, giving you a lot of options to play with. In addition, if you mow, you can vary the timing and number of times you mow a particular spot during the season, but you can also adjust the mower height each time. Grazing is even more flexible because you can vary timing, intensity, and duration to achieve a wide variety of results. Fire is the least flexible, but even so, you can burn during any season, as long as you have enough fuel (dry vegetation) present to carry fire. You may also be able to take advantage of fuel and weather conditions to create either a complete burn or a patchy one, depending upon your preferences.

If both fire and grazing are options for you, patch-burn grazing can be a terrific way to create a shifting mosaic. Within a patch-burn grazed prairie, large grazing animals (e.g., bison or cattle) focus their grazing in recently-burned areas much more than unburned areas. Managers burn a new patch each year to move the grazing pressure and rest around the grassland. We usually burn around 1/3 to 1/4 of the total site, depending upon how many years it usually takes for burned/grazed areas to fully recover. In drier and/or less productive sites, recovery from being burned and then grazed all season takes longer, so we burn a smaller percentage of the total area each year. Within that basic framework, there are lots of options regarding stocking rate, timing and duration of the grazing period, and more – allowing you to tailor the general approach to your specific objectives.

Patch-burn grazing at The Nature Conservancy’s Platte River Prairies. Cattle are focusing their grazing on a recent (summer) burn but have access to the unburned areas as well.

Patch-burn grazing, however, relies on frequent and consistent use of prescribed fire, which isn’t logistically possible for a lot of people. As a result, we’ve experimented with other approaches to “focal grazing” where we encourage grazers to do most of their grazing in one part of a larger grassland and then shift that focus patch around through space and time. One of those approaches is open gate rotational grazing, which takes advantage of the kind of fence and water infrastructure most ranchers already have, but creates more heterogeneity than most rotational grazing strategies. This summer, we’re testing virtual fencing as a way to influence cattle grazing patterns, and have a lot of optimism about that technology as well.

An additional method we’ve used over the years, and (finally) the topic of this post, is something we call patch-hay grazing. It’s not very complicated. It’s really just patch-burn grazing, but instead of burning, we cut hay where we want to focus grazing pressure. As with patch-burn grazing, the key is to create an area where fresh, nutritious grass growth, without any standing dead vegetation, lures grazers in and encourages them to spend most of their grazing time in that patch.

Cattle grazing in recently hayed prairie back in 2013.
Same prairie/year as above. You can see the edge of the unhayed prairie on the left side of the photo. The cattle had access to the unhayed area but spent little time there.

The results we’ve seen with patch-hay grazing have been very similar to patch-burn grazing, though we are still experimenting and learning. Both cattle and bison gravitate toward recently hayed areas and spend the majority of their time grazing there. That leaves the unhayed areas mostly ungrazed.

We’ve cut hay at various times of year across the growing season and have seen good success with everything we’ve tried. I’d say the biggest concern we’ve run into is that if we cut hay too late in the summer (e.g., late August), especially if we have a dry autumn, there isn’t always enough regrowth to lure grazers in. When that happens, they wander around and create small grazing lawns distributed across much of the pasture. The next spring, they tend to start on those small patches again instead of focusing solely on the hayed area. It’s not terrible, but the grazing isn’t as concentrated as we’d like.

This hay patch was cut in early August last year (2025). This photo was taken after cutting and before baling.
Here’s the equipment that was used.
Hay on the ground after cutting.
Here you can see part of the unhayed portion in the background.
This picture shows the same site the following spring (mid-April of 2026). The green patch is what was hayed in August of 2025.
Here’s a closer look at that hay patch. You can see the cattle (little black specks) grazing in the hayed area.

The nice thing about the concept of patch-hay grazing is that it can be incorporated into lots of situations. You can run it as a season-long grazing system as we usually do – cutting hay to concentrate grazing in one area more than others. But you can also mix some hay harvesting into just about any grazing approach. If there are parts of a pasture cows don’t often graze, you could hay those areas (assuming topography allows it) to encourage more grazing pressure. You could also incorporate haying into a rotational system. You could mow portions of several pastures, for example, to create more patches of higher forage quality and increased habitat heterogeneity at the same time. There’s plenty of room for creativity, depending on what you’re trying to accomplish.

Regardless of the tools and techniques you use, a focus on habitat heterogeneity and a shifting mosaic can help you support the broadest possible diversity of species in your prairie. That diversity is important for its own sake, of course, but it also props up the ecological resilience of the site. Given the raft of challenges facing prairies today, the more resilient we can make them, the better.

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Notes on hay-patch grazing logistics: For those who are interested, here are a few additional things we’ve learned.

First, we have had no problem with cutting hay while cattle are in the pasture. The cattle started grazing the hayed area almost immediately after the mower went through and walked between the wind rows without messing them up.

Second, lower mowing heights seem create more attraction for grazers than when the hay mower is set higher. I assume that’s because there is less thatch and old material present, but I don’t know for sure. It’s just what we’ve noticed.

Third, you might wonder if you can just mow instead of cutting hay and baling/removing it. Sure, but a bunch of dried material lying on top of the green regrowth counteracts a lot of the attractiveness of that regrowth. Now when a grazer takes a bite, it’s probably going to get some old dead stuff in its mouth along with the new green growth it really wants. Mowing may still work if the rest of the pasture is tall and dense because the mowed area will probably be more attractive than that, but it’s certainly not as good as haying.

Finally, you might wonder how to calculate a stocking rate when you’re cutting and removing a bunch of forage from the site. When we figure stocking rates for patch-burn grazing, we start with the recommended stocking rate (based on soils, rainfall, etc.) for the whole pasture and that’s usually pretty close. Often, we find ourselves bumping that rate up over the first several years until we find the sweet spot where we get good grazing pressure in the burned areas but light enough grazing elsewhere that previously burned patches recover within a few years.

We calculate stocking rate the same way when we cut hay instead of burning. It feels like we’re able to graze as normal while still cutting hay from about 1/3 or 1/4 of the site. I’m not really able to explain that because it seems like we’d be removing some production from the site and reducing the amount of available forage. One reason might be that we typically mow the tallest and most rank grass, which the cattle weren’t going to be grazing anyway. Regardless, we’ve never yet had an issue with using the same stocking rate as we’d use with patch-burn grazing.

Oh, and it hopefully goes without saying that any of the general approaches here will still require managers to watch and adapt management over time. In addition, there will surely be additional work needed to help suppress invasive species and/or encroaching woody plants, or whatever other challenges your individual prairie faces. None of these approaches should be seen as a recipe that, if followed, will cover all the needs of a prairie.

How Diverse Should My Prairie Restoration Seed Mix Be?

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“I’m doing a prairie restoration project – how many plant species should I put in my seed mix?”

The answer to that depends on why you’re doing the restoration project.  Do you want a planting that is both beautiful and resilient?  Are you trying to enlarge or reconnect existing habitats?  If the answer to either question is yes, the answer to your question about species diversity is easy: put as many species in the mix as you can.

We aim for seed mixtures of 150-200 plant species for most of our restoration projects at the Platte River Prairies.

Ecologists are still arguing in the scientific literature about how to measure the value of plant diversity in habitats.  We know a prairie with hundreds of plant species has advantages over a grassland with only a few, but there’s a lot of room in between those extremes.  How do you calculate the value of a plant species that exists in low abundance and only in a few scattered populations?  We know pollinators need to have plants blooming at all times across the field season, but how many plant species need to be blooming at a time to give them what they need?

Those, and many others, are important questions, and we’ll learn a lot from continuing research efforts.  In practice, though, we don’t have to wait for the answers.  There are lots of reasons to maximize the number of plant species you put in your seed mix.  Here are some of them.

1 – Create beauty. Every plant species has its own individual architecture and charm. When you put a lot of them together, they create a prairie with varied heights, shapes, and colors. To most people, that’s more attractive than something that looks like a wall of monotypic vegetation. Both abundant and less abundant species contribute. Abundant species form the melody and the rest create harmony, dynamics, and accents. A monoculture of big bluestem or switchgrass is like an air horn – it can serve an important role, but if you were going to listen to something every day, wouldn’t you prefer an orchestra?

The Greene Prairie at the University of Wisconsin – Madison Arboretum is one of the prettiest places I’ve ever been.

2 – Fill all the spaces. There’s a lot of variation in soils, topography, and other conditions, even on what looks like relatively flat ground. One the most fun aspects of using a high-diversity seed mix is the chance to watch plant populations find their optimal growing sites. Some of that will happen within the first few years. As plants establish, you’ll notice correlations between species occurrence and elevation, soil moisture, or other factors. In our Platte River Prairies restorations, for example, blue vervain does better in low wet spots and hoary vervain thrives in drier soils.

However, you’ll often see big changes after the first few dry years, fires, grazing bouts, or other events that put a little pressure on plant survival. That’s when the community really starts to take shape. Populations of individual plant species either grow or shrink, depending on how well matched they are to local conditions. This is when we often see stiff sunflower disappear from sandy wetland edges, but expand in number on higher ridges. Meanwhile, sawtooth sunflower expands its populations along wetland edges and drops out of higher sites.

It’s impossible to precisely predict what plant species will best match the conditions in each square foot across a site. However, throwing out seeds of many plant species will make it more likely to create good matches across all those little areas. More importantly, it’ll mean that multiple plant species will establish in each of those spots, which is important for reasons discussed below.

Stiff sunflower (shown here) likes drier sites than Maximilian sunflower, which likes drier sites than sawtooth sunflower. Sometimes is takes a while, but those species will settle into their appropriate habitats.

3 – Fill all the roles. Every plant species has a unique mix of strategies it employs as it competes for space in the plant community. Some thrive best by growing tall and dense and shading out their neighbors. They may gain territory in years with no fire or grazing, and when precipitation is substantial. Other plants are opportunists, and can quickly pop up (either from seed or by ballooning from basal leaves to large, robust plants) after events that suppress the competitiveness of others.

There are plants that flourish during wet years and others that prefer droughts. Some plants are preferred by grazers or browsers and others taste bad or are hard to digest. There are even plants (legumes) that cooperate with bacteria to convert nitrogen from the air into ammonia fertilizer they and neighboring plants can utilize.

Plants also vary in how quickly, and in what ways, they move around. Some invest their energy in slowly expanding their very local footprint. Others try to spread quickly across large areas, via seeds, rhizomes, or both.

If you have a plant community that includes species that fill all those roles, and many others, it will be more productive and adaptable than one with only a few plant species.

Illinois bundleflower (Desmanthus illinoensis) is among the best native legumes at fixing nitrogen (taking atmospheric nitrogen and turning it into ammonia.)

4 – Build networks of relationships.

A diverse mix of plant species also facilitates a lot of interactions and relationships between prairie species. That includes interplay between plant species themselves, as well as between plants and other taxonomic groups, including animals, fungi, and more.

Plants are in constant competition with each other for light, moisture, and nutrients. That competition can help keep any one species from becoming too abundant or dominant. The relationships between plant species, though, are much more complex than that, and often one plant species can provide benefits to its neighbors, even while competing with them. That can happen, for example, through the changes one plant makes to soil structure or nutrient composition around its roots that helps nearby plants. Other times a plant that is a favorite food of a grazer can “hide” from hungry animals beneath the canopy of another species that is spiny or less tasty.

Every plant species has individual relationships with fungi, bacteria, and/or other tiny entities in the soil, so a diverse plant community facilitates the presence and survival of a more diverse community of soil microorganisms. Plant diversity is also crucial for supporting a wide variety of pollinator species by providing a consistent availability of flowers across the season and a broad range of pollen and nectar nutritional choices. Similarly, a wide assortment of plant species means similarly wide assortment of seeds for the many animals (vertebrates and invertebrates) who eat them.

In addition, there are numerous specific relationships between invertebrate and plant species. Some bees, for example, can feed (themselves and their larvae) from only few related plant species, such as sunflowers or sages. Many people know that monarch larvae need milkweed for their food, but there are similar relationships between countless other insect and plant species. In many cases, an insect species can’t survive in a prairie without its host plant(s), and in some cases, neither plant or insect can survive without the presence of the other.

The blue sage bee (Tetraloniella cressoniana) depends entirely on the presence of its sole food plant – pitcher (blue) sage (Salvia azurea).

5 – Resilience.

Because of the varied roles and relationships each plant species brings with it, a diverse plant community is much more resilient than one with fewer species. Multiple species of milkweed means monarchs can survive even if one milkweed species suffers from a disease outbreak, late frost, or other stress. A community with plants that thrive in wet years and others that thrive in dry years can maintain consistent forage for grazers, seeds for birds, and pollen for bees and butterflies, no matter what precipitation pattern comes along. Opportunistic plant species can quickly fill in when normally-dominant plants are temporarily weakened by grazing, fire, or other stressors.

But what about?

Ok, you may be thinking, if someone has all the money and time in the world, planting a diverse seed mix is probably the best option. Seed of some species can be really expensive, though, and for a lot of species, seed isn’t even commercially available! What do I do about that?

First of all, talk to other people doing restoration work in your area and learn from them. You may be able to compare prices and availability between multiple commercial sources and cobble together a better mix than you can by buying from a single source. Harvesting your own seed can also help you fill gaps you can’t fill through commercial vendors. Again, local experts can help you. Once you identify sites where seed harvesting is allowed, the biggest challenges come from figuring out when seeds are ready, identifying which plants have good seed in them, and then knowing how quickly the seed needs to be planted before it loses viability. Harvesting your own seed can help you supplement what you buy, and either increase your plant diversity, save you money, or both.

Harvesting your own seed can be both gratifying and cost effective.

As you acquire your seed, be sure to ask questions about geographic and genetic origins. If you’re in Minnesota, seed from plants from Kansas might not survive well at your site, even if the seed is from a species that’s native in your area. Likewise, make sure you know the site history of any prairie you plan to harvest seed from, especially if it isn’t an unplowed remnant prairie.

Unfortunately, we still have a lot to learn about what matters in plant genetics, relative to prairie restoration. We’re all just doing the best we can with what we know at the moment. While bringing in genetics from sites far from yours can be problematic, including seed from a variety of genetic origins might boost the adaptability of that species in your restoration project. Again, talk to local experts to see what they’ve learned over the years and do your best to at least know where your seed came from so you can make the best decisions you can.

Lastly, knowledgeable locals can help you other questions, including seeding rates, weed control strategies, and more. For example, it’s often crucial to think about how much perennial grass seed you use, relative to wildflower seed. Some grass species can quickly dominate a planting before other plants have a chance to get established. Similarly, knowing what invasive plants can be problematic and how you can reduce their establishment can spell the difference between a successful planting and a failed one.

Do the best you can. Add as many locally-native species as you can find and afford to your seed mix. Get advice from experienced people in your area on the local nuances of restoration work. Then, enjoy the awe-inspiring process of a prairie community rising from the ground and becoming a complex, dynamic ecological system.

Other resources:

The blog for the Grassland Restoration Network is a fantastic resource for anyone working on prairie restoration projects. There is also an annual gathering of network members at sites around the U.S. where information is exchanged.

If you live in or near Nebraska, you might find this restoration guide helpful. It includes species lists for various habitat types, strategies for seed harvest and planting, and much more.

The Bureau of Land Management’s Seeds of Success Program is aimed at “increasing the quality and quantity of native plant materials available for restoring and supporting resilient ecosystems.”  The program includes a strong set of protocols, many of which are relevant to site-based restoration programs.