Seeking feedback - Grass to Food Forest

Hello all,

I have 2.86 acres of land and approximately 1.5 acres of that will be converted from a grassland environment to a food forest. This will all take time for me to slowly implement but I'm trying to figure out a way to change from a plant community dominated by grass to one that has a greater diversity of plants that will prepare the soil and the land for the main food forest plants. The plan is to find a relatively cheap (financially, not necessary cheap in time) to do this. I will be focusing on projects in and around zone 1, but I want the outer areas to be steadily improving so as I shift my focus to zone 2 and 3 I will have a much better starting point than the grassland I currently have.

What I'm thinking about doing is to use a mower (eventually a scythe once I get a good one) and perhaps a rototiller to knock down the grass in a decent sized area and smooth out the ground (for reference my soils are mostly made up of clay but also sloped and my property is on the west side of Washington State in the South Puget Sound area - seasonal stream flows through the property). Once an area has been treated I would place cardboard over it and then mulch it with straw and wood chips. I might also add some manure or compost before I added the cardboard if I can find a good supply. This work would be done in mid to late spring and then the treated area would sit over summer into the fall. Once fall comes along I would broadcast a seed mix of mostly native (I want them to take care of themselves) plants. I would do a follow up broadcast in early spring for the species that prefer that timing. I will list my current seed mix (have not purchased it) at the end of the post. The hope is that at least some of the species that I'm thinking about would survive and start transitioning the treated area from grassland to an early open shrub/forest mix.

Each year I would repeat the treatment on an adjacent area and potentially re-seed the previous year area to help some species become established. My hope is that this would help prep the land for the food forest and do a bunch of work for me while I complete the zone 1 and 2 projects and slowly expand outward. Broadcasting seeds should be a lot cheaper than buying a bunch of plants and if it works the soil should be greatly improved and it should be far easier to establish the main productive trees and shrubs later on. Also, I'm planning on making my first broadcast mix of seeds very diverse and then take out species from future broadcasts if none of them germinated in the earlier broadcasts. I'm not sure how long it would be before I could start planting my primary productive trees so I would want the treated areas to mostly take care of themselves and just steadily improve the soil, provide wildlife habitat and perhaps a few small yields for my family and I.

As the food forest was implemented I expect many of the species I picked for broadcast would die back and be limited to the edges of the forest. Their main job is to be my workers preparing the future food forest area while I work on other projects. I want to look out my window and see the grasslands changing to a mix meadow, shrub, forest environment that will be ideal to plant my primary productive plants into as I have the time and resources to get them.

So what do you all think? Feedback on the general technique and feedback on my species list would be great!

Here is the current list of species - I have found seed sources for all of these and some I can collect myself:
- Crimson clover (nitrogen fixing)
- White clover (nitrogen fixing)
- Red alder (nitrogen fixing - can be coppiced and will be a long term support tree for my food forest)
- Big leaf maple (easy to coppice - will be a long term support tree for my food forest - good mulch producer)
- Bluebunch wheatgrass
- Western Yarrow
- Serviceberry (native edible - will be a long term food plant in my food forest)
- Arrowleaf balsamroot
- Colorado blue columbine (not native to my area, but native variety does not like open areas - will introduce the native species as the canopy developes)
- California poppy
- Miniature lupine (nitrogen fixing)
- Snowberry (not edible, but great for pollinators)
- Showy milkweed
- Snowbrush ceanothus (nitrogen fixing)
- Fireweed
- Blue elderberry
- Red-flowering currant (great for humming birds)
- Mock orange
- Sickle Keeled Lupine (nitrogen fixing)
- Shore pine (fast growing and resilient - about 60ft max height - would cut most down for woody debris, but some would remain as habitat trees in the food forest)
- Twinberry (great for hummingbirds)
- Cascara (small tree, great for wildlife)
- Oceanspray
- Nootka rose
- Blue camas
- Prairie Junegrass

Hi Daron! I would personally recommend avoiding the lawn mower and rototiller. Rototillers are very effective at making your grass "problem" worse. The rototiller is going to dig too far into the earth, shred the grass roots and then shoot them allover the place. You will very effectively being multiplying and spreading the grass. I have personally worked in a food forest that was built on top of grassland. This food forest required hundreds of volunteer hours each year to deal with the grass infestation. The reason they had this problem was because they sheet mulched the area. I understand that sheet mulching may work in some scenarios but it unfortunately did not work so well for this food forest.

My recommendation: bring in a pig and some chickens. A pig can clear about 250 square feet in a summer. So four pigs could till about 1000 square feet. Using animals is a win win situation for you and them. They get a free buffet of wild edibles, insects and rodents (if present). You get an edible work force/auto fertilising system.

My first reaction is that you're talking about putting a tremendous amount of time and effort into the area you say you're wanting to develop on its own while you develop other areas with more focus, intent and effort.

In many environments, the natural progression is from grassland toward savanna and possibly onward to forest. If this were my project, in those outer areas that I wanted to start transitioning while I worked on other things, I would pick some of the pioneer type plants I wanted to use to shift the area away from grasslands and do one square foot plantings of these pioneers, say on a 20 foot grid.  And then go back to the higher priority areas and let those plantings go about their business while I focused on the other projects.

In other words, Introduce the next stage of succession, but leave it to progress on its own. Small changes and self-replicating systems that you start and allow to cascade. Lots more return on energy invested than mowing, tilling and sheet mulching, I think.

My recommendation: bring in a pig and some chickens. A pig can clear about 250 square feet in a summer. So four pigs could till about 1000 square feet. Using animals is a win win situation for you and them. They get a free buffet of wild edibles, insects and rodents (if present). You get an edible work force/auto fertilising system.

Thanks for the feedback! I wish I could use animals but at this stage of life with my day job I won't have time during the week to work with animals. We also have a very healthy coyote pack in the area that has already taken down a deer on my property. So it would take some prep to set things up for domestic animals. But I fully agree that using animals would be the best labor wise - I just don't think I'm in a position to use them at this time. Perhaps down the road - I'm planning on having chickens at sometime in the future once I have things setup for them. Likely, that will take a few years.

I can avoid using the rototiller though - I have used them before with success (I just use them once on a given area and then never again - just to get things going) but I have also skipped that step and gone strait to the mulching after the mower. My experience is that if the mulch is thick enough I can smother out the grass fairly effectively but of course that takes a bit of work. What have you all found?

In many environments, the natural progression is from grassland toward savanna and possibly onward to forest. If this were my project, in those outer areas that I wanted to start transitioning while I worked on other things, I would pick some of the pioneer type plants I wanted to use to shift the area away from grasslands and do one square foot plantings of these pioneers, say on a 20 foot grid.  And then go back to the higher priority areas and let those plantings go about their business while I focused on the other projects.

Yup, I get the succession pattern and given enough time my property would convert on its own. The plants I have chosen are based on that concept - some small meadow plants, mixed with a few shrubs and a smaller amount of pioneering trees. My expectation is that overtime with that mix the plant community balance would shift away from the meadow plants I picked and towards the shrubs and the pioneering trees. The grid idea could work but my experience so far is that while there will be some pioneering species mixed in (an improvement!) the progress is fairly slow and the grasses will remain the dominate plant until the shrub layer fills in or the pioneering trees create a canopy to shade out the grass. From past sites that I have seen this could take 10+ years and some systems even after 20 years still have an understory dominated by grass depending on the orientation of the property. My property is fairly long and I'm concerned that there will be a lot of light penetration to the understory level (great for a food forest!) that will keep the grasses growing.

I do agree that what I'm proposing is a fair bit of work - but from past projects I think I could treat a decent area in a weekend and my plan would be to dedicate several weekends (with help from family and friends!) in late spring or early summer to this and then that would be it for the year until the seed broadcasting part (the seed broadcasting should be fairly quick and easy). My goal would be to convert the whole 1.5 acres in about 7 to 8 years. This would require that I treat about 8,700 square feet per year. I think the biggest advantage of doing this is that it should really improve my soils and also establish the foundation plant community for the food forest.

What do you all think about mulching pasture grass / hayfield grass (bit of a mix on my property) after it has been mowed? How thick would the mulch need to be to successfully kill it off? Also, what about broadcasting seeds about 6 or 7 months later directly into the mulch (mostly native species). Do you all think that would work? I have an unlimited supply of cardboard (local college recycles a ton on a weekly basis and I have permission to take what I want) to use as the base layer of the mulch and I should be able to get straw to use as mulch without too much issue.

My biggest concern is that I will do all the work to mulch the area and then the seeds won't take. My second biggest concern is that the mulch won't be able to keep the grasses down.

Thanks Genevieve and Peter for the feedback! It has given me somethings to think about!

We are trying to do something similar. In one area we have begun by clearing areas about 1 m across, planting a tree plus a few smaller things. Each one has to protected against hares and kangaroos. We've only been doing this for one season so it's very early days. In another area we mowed a 12 m wide strip, ripped three lines and planted native trees and shrubs, 320 in total, all small seedlings. We're hoping both methods work.

Here's a photo of our grass land. We have forty acres of this to plant out.

Hi

i would highly recommend all the Geoff lawton video on youtube.

also if swales/earthworks are planned they should be the first port of call.

recommend robinia pseudoacacia (black locust) as a tree. only down side are the thorns

good luck

Have you considered "solarization?"
https://permies.com/t/43714/info-Soil-solarization

It might work for your scenario, because you can set it up in a few hours, ignore it for a few weeks/months, and then plant seed on it with much less competition. It is especially good at establishing a meadow.

I like to get a meadow established at a new site first, because it rapidly increases the beneficial insect populations, and you get flowers within months (assuming you use a mix of annuals and perennials). A meadow of wildflowers is good for wildlife, and your soul A meadow quickly builds biomass and improves the soil too, with nothing more than the effort to plant it, and a single mow per year. In most places, if you time your sowing well, it also requires little irrigation to establish and zero to maintain the meadow, even on a slope.

In the future, if you decide you want something else where the meadow is, it is pretty easy to mow if down and mulch over the top of it to establish something new. I suspect most trees or shrubs would prefer to be planted in a meadow and not surrounded in grass.

Mmmm is it possible your problem is not the one you think it is ? Could it be a deer problem? otherwise why is the land not covered in trees ?

You're going to need a huge amount of material to sheet mulch that much land. Huge. 1.5 acres is roughly 75,000 square feet.  Sheet mulch that to say 4 inches and you're at 25,000 cubic feet. A cubic yard is 27 cubic feet. So roughly 1000 cubic yards. That's 100 dump truck loads that you need to procure and spread. Even one tenth of that area would be a major undertaking and possibly very expensive.  

Or you could treat localized "stations" - amend and sheet mulch "oasis" in the sea of grass.  You'd have to figure out the right size and spacing but for easy math let's say 5x6' stations (which is very small) - 30 sq feet, roughly 1/3 of a yard of material per station, 30 stations per dump truck load if you do it all at once (The hard way).  Or every time you mow the field you use a bag on the mower and use the cuttings to build stations a few at a time (the easier way). This scenario will still require a lot of maintenance keeping the sea of grass from taking over your stations.

Alternatively, you could plow / disk / plant successive cover crops over the course of two seasons to smother the existing pasture.   Then plant a more benign legume rich pasture mix and plant your localized stations. Cut the pasture periodically and use it to mulch an expand your stations. You'd need the right equipment to do it this way.

Karl Trepka wrote:

recommend robinia pseudoacacia (black locust) as a tree. only down side are the thorns

Another downside is their invasiveness...  You cut one down (you will have to, sooner or later) and dozens of robinias will sprout up from the roots of the felled tree, meters away from it, in places where you may not want them...

And another likely downside: it is reported to deplete soils, despite its alleged nitrogen-fixing quality.

O. Donnelly wrote:

Or you could treat localized "stations" - amend and sheet mulch "oasis" in the sea of grass.  You'd have to figure out the right size and spacing but for easy math let's say 5x6' stations (which is very small) - 30 sq feet, roughly 1/3 of a yard of material per station, 30 stations per dump truck load if you do it all at once (The hard way).  Or every time you mow the field you use a bag on the mower and use the cuttings to build stations a few at a time (the easier way). This scenario will still require a lot of maintenance keeping the sea of grass from taking over your stations.

Your "stations" would not be swamped by the sea of grass if the heap of mulch is tall / thick enough (at least 40...50cm), and better still, if it's a bit bigger than those 5x6'.  Grass would grow around the heaps, but not through them.

I have been employing a similar strategy on my land for the past 3 years.

My plot is comparable in size to the one described in the original post. It was sown with alfalfa 7 years ago and mowed 3 times a year.  Alfalfa has its benefits - drought-resistant, nitrogen fixing legume with deep tap root which breaks up the dense clay soil - as well as its drawbacks - it outcompetes grass and all other herbaceous plants except dandelion, and attracts populations of voles, which are a huge problem if you want to plant trees.  

I have been mowing the alfalfa, drying it into hay, then heaping the hay in "islands" in the areas where I intend to plant trees.  I make the heap at least 40 cm thick, and after a while I may top it up if it settles too much.  I leave the heaps to rot in place for at least 12 months.  The size of the mulched areas vary from a couple of square yards to 20-40 square yards each.

Alfalfa hay is quite tough and a lot of it is still just mouldy hay (rather than compost) at the end of those 12 months.  But the bottom 1/4 or so is turned into fine humus by the earth worms.  At this point I move the heap elsewhere (to form another island). I seek out and destroy any vole nests that were created under the mulch heap - I have to be ruthless, otherwise they will kill my newly planted trees.

At this stage I have a clean slate - soil bare of vegetation but fertile due to rotted vegetable matter - in which I can plant my trees.  Once the trees have been planted, I mulch again around each tree, this time with (a) pea gravel close to the trunk; and (b) wood chip in a wider circle.  I try to make the wood chip mulch circle as wide as possible; if the trees are planted close to each other, the circles may meet and form a continuous area.  Both pea gravel and wood chip are uninviting to voles and offer some degree of protection against them if laid down in the right thickness and breadth.  I don't recommend other mulches if voles are a problem.

Of course, the size of the plot and the periodical availability of the mulching material (hay) means that I can only prepare and plant one circumscribed area at a time, and the process for each of these areas takes at least a year.  However, it is better than the alternatives, i.e., tilling before planting (the grass WILL come back), mulching the whole area in one go (impossible task), or neither of the above, i.e., planting in the midst of the herbaceous vegetation (trees will be swamped).

Levente - your method  is very close to what I did when I planted my fruit orchard. Although I didn't replant the field initially to alfalfa or other crops. I simply left it as a diverse pasture sward. I mow or scythe the pasture, make huge piles wherever trees are going, sometimes I double dig and amend the station first and then let it sit over the winter, or sometimes I just dig it 6-8 months after covering the station with hay (the next spring). I do the same thing as you with gravel mulch.  

But for me the native flora does try to come back wherever a ray of light hits an area of depleted or thinned mulch. It may be that bc its native pasture va alfalfa and some of the plants have tenacious runners that do burrow through hay and gravel to reach the light.  In any event it is work to keep adding mulch and pulling out weeds. Not a terrible amount but it does take up time.

For my property the main reason there is no trees coming in is that it has been managed for hay production for decades and has been mowed down every year - this was before I owned it. The soil has almost no topsoil and is just grey clay. This is the reason why I want to focus on soil production in addition to reducing the amount of grass and replace it with plants that will better help establish a food forest.

In regards to the amount of mulch needed it will take a large amount of mulch but I'm spreading this out over roughly 8 to 9 years based on my current plan. This would require an area of 8,000 to 9,000 square feet of mulch each year. My strategy will be to mow the area I want to mulch and then apply cardboard with straw on top. This would require around 110 to 115 cubic yards of mulch on a yearly basis - using straw bales also allows me to easily transport the mulch over time. I will also be adding woody debris and wood chips on top of the straw as I have it available. This work would start in February with the goal of finishing by May - that would mean I need to mulch at the high end about 3,000 square feet per month for 3 months (just under 40 cubic yards of mulch per month).

The mulched area would then be mowed as needed with a scythe to help keep weeds from germinating through out the year. In the fall and also in the following spring I'm planning on using seed balls to apply a seed mix. I'm not sure which species will work the best so I'm planning on using a large number of species and then observe the results so I can adjust my seed mix based on what germinated. This will allow me to tailor my mix to my property. The new plants should be able to out compete any grass that does come up and hopefully a good balance will be established.

By spreading the work out over three months each year and the total work over 8 to 9 years I think it is completely manageable. If I did this work four days a month over the three months I would only need to mulch 750 square feet each day. So far this year on my existing projects (not part of what I'm proposing) I have already mulched about 1,800 square feet - this was done over the last 2 months and some of it first involved double digging areas and also digging out black berries. So based on the amount of work I have been able to complete so far I don't think what I'm proposing will be a problem.

I do restoration work for a living (so far this planting season we have planted about 20,000 trees and shrubs and have another 15,000 to plant over the next month) and in my experience small patches in grass generally have trouble dealing with the grass. Even when the trees/shrubs are established it takes a longtime for the grasses to be shaded out and replaced by a forest understory community. We are shifting our work to mulching large areas early in the season and then planting later in the mulched areas - these mulched areas will create large islands with grass corridors between the islands. One advantage of this is it is a lot easier to spread mulch before you have trees in the way. Another advantage is that by planting months after we mulch the area we give the soil time to start changing to a fungal based system. At one of my sites for my work I'm currently planning a 5 year research study to compare different ways of establishing trees in a grass field. This is mostly being done to satisfy the agencies funding the restoration work but it will also be very useful information. I find that most of my restoration work involves planting plants in old hay or pasture fields.

My main question in my earlier post was about the species I was looking at using for the seed mix and how well they would germinate if broadcast over mulch. Still curious about the species mix but reading other posts in different threads I think making seed balls (my soil is all clay) will be one of the best options for me.

I'm not quite following the part about seeding on top of the mulch. If you've put down enough cardboard, straw and woodchips to smoother the grass, it seemed like it would be too thick for seed to germinate and take root. Maybe I'm missing something obvious. Apologies if that's the case.

What about transplanting seedlings in holes in the mulch?  You could pretty easily grow out hundreds of plugs each spring. Could have a nice mix of perennial flowering shrubs and herbs.

Control through rampancy -  

Scalp the grass down to the dirt and heavily seed with cover crops.

O. Donnelly wrote:I'm not quite following the part about seeding on top of the mulch. If you've put down enough cardboard, straw and woodchips to smoother the grass, it seemed like it would be too thick for seed to germinate and take root. Maybe I'm missing something obvious. Apologies if that's the case.

What about transplanting seedlings in holes in the mulch?  You could pretty easily grow out hundreds of plugs each spring. Could have a nice mix of perennial flowering shrubs and herbs.

My current thought is that by letting the mulch sit for about six months before sowing the seeds (in seed balls) that the mulch should decompose a fair bit. Most of the species I will be planting via seed are native plants that need to sit overwinter before germinating so that would give more time for the mulch to breakdown. The following spring sowing would of course have even more time for the mulch to breakdown. My hope is that by timing things correctly the grass will be mostly killed off and then the mulch will have time to breakdown enough for the seeds to germinate - I'm also hoping that the seed balls will help with germination. The main reason for using seed is to save time and money - plugs are cheap but seeds are even cheaper and broadcasting seeds is faster than planting plugs. I also don't have a good setup for growing my own plugs at this time - it is on my list but might take a couple years before I have it ready.

I'm honestly not sure if my seed strategy will work. I have seen it done successfully for prairie restoration in my area but I have not seen it done for non-prairie species. For prairie restoration the groups I have talked with use seed balls or soil injection depending on the site / species. Luckily, the mulch will be a good thing regardless and if my seeds fail to germinate then I can use plugs the following year.

I think you're headed in the right direction.

As long as a dense, multi-story canopy is lacking, grasses will be a major part of the plant community.  They will come up through and around cardboard mulch.  Especially if you are irrigating.  The only really effective thing to do is to plant trees/shrubs/vines/etc. and wait for the canopy to close.  Focus your cardboard/paper-mulch around the bases of your young trees to relieve competition, and help them get established. Once they are established, they will out-compete the grasses naturally. Yes the transition period will be awkward - but that's puberty for you...

Plan your trees and shrubs in dense rows that you can reach into from both sides.  This makes management/harvest much easier than 1.5 acres of solid thicket.  Chop-and-drop pruning debris and undesirable woody volunteers into your alleyways as a weed-suppressive/soil-feeding mulch.

Seed is hit-and-miss.  It works great if you are dealing with a highly-disturbed site with lots of exposed soil.  Seed-to-soil contact is important.  Seed-balls can help you there, but again, you are also fighting an established/competitive turf, so I would recommend transplanting and dividing established plants as much as possible to start with plants that can compete out of the gate.  In the PNW, Alder should definitely be at the top of your list for easily-propagated coppiceable nitrogen-fixing pioneer trees. Maple locust hazel willow dogwood are also very obliging.  As for herbs, a nitrogen-fixer is the most important component, and here, white clover is king (Lupine is also a pretty good N-fixer, though slightly less resilient year-to-year).  Everything else is just icing.  Definitely use what is already growing on your property as much as possible. Burdock and comfrey are very useful herbs in orchard systems; their broad leaves and deep roots work wonders from several angles.  Deep-rooted radish is also a good self-sufficient soil-builder (and in the PNW, it is high probability you will have mustard family coming up all over anyways, so fight fire with fire ya?).

If you have clay soil, the worst thing you can do to it is rototill it.  Number One: Add organic matter.  Number Two: Don't ever ever drive on it, and don't walk on it if you can help it.  Regarding organic matter: Plant roots are constantly injecting carbon into the soil as they live and die, so let them be your primary source of terrestrial carbon.  All you have to do is take a deep breath and let go of controlling the process.  They do it without compacting or destroying soil-aggregate structure.  Their residue acts as a glue to hold soil aggregates together, and preserve pore space.  As old roots decay, they leave perfect channels for air/water.  Progressively mulching the surface helps too, but not as much of it makes it *into* the soil (thank you worms).  Roots are where it's really at!  Cover crops are the "next level" of mulching.

Well that's all for now, though I'll think of another dozen things in the next five minutes. Back to work!

-B

Thanks for the feedback! I appreciate everyone's comments - got a lot to think about and luckily time to plan it all out before I get started. I have completed buffer straps along the edge of my property but I won't be starting the next phase till fall or next winter.