We have a small hobby farm and we've dedicated a field to forest gardening. We have a little less than an acre to play with. We're going for a simple "wedge" shape with tall nitrogen fixing trees at the back of the field (the north side) going down to smaller fruit trees and shrubs. We've selected and planted the trees (robinia pseudo acacia, and alnus cordata) and are now going to sow a grass mixture for the ground cover layer on the rest of the field (not around the trees). We're using the clover+ryegrass+fescue mix from Martin Crawford's book.

The field is full of other grasses and weeds and our doubt is how to properly sow it. Should we plow then till to try and kill off as many weeds as possible? Just till to try and leave the soil structure intact? Till multiple times over a few weeks to kill of the weeds? Any ideas are welcome.

It would have probably been a better idea to till the whole field in October and sow it. At least that's a common advice for clover. We could then have plated the trees after the ground cover. As it stands we'll need to be more careful with mulching around the trees. The Crawford book lists the grass mix as to be sown in April though, so that's what we're doing.

What purpose are you hoping to achieve with the grass mix? Are you intending to let livestock graze it?

My experience of grass around our fruit trees is that it competes for nutrients - the trees I have mulched around and smothered the grass are doing much better. Typical species that permies like to plant in orchard type areas are nutrient accumulators and mulch plants. Clover fits this bill (fixing nitrogen) but I'd also look at planting comfrey which has a deep taproot and returns trace minerals to the soil surface. In our food forest by ground layer has strawberries (running freely all over the place now), Comfrey, redcurrant bushes, rhubarb, globe artichokes etc... Where possible I have been deep mulching with woodchips too.

Michael Cox wrote:What purpose are you hoping to achieve with the grass mix? Are you intending to let livestock graze it?

We do have some goats that we might let graze but it's mostly for nutrient accumulation, thus the clover as you mention.

Michael Cox wrote:My experience of grass around our fruit trees is that it competes for nutrients - the trees I have mulched around and smothered the grass are doing much better. Typical species that permies like to plant in orchard type areas are nutrient accumulators and mulch plants.

We're not sowing under the trees just on the rest of the field. We've planted the larger trees and I'm planning on adding some mulching around them to make them grow faster (probably some straw just around the trees and possibly some plastic between them.

Michael Cox wrote: Clover fits this bill (fixing nitrogen) but I'd also look at planting comfrey which has a deep taproot and returns trace minerals to the soil surface. In our food forest by ground layer has strawberries (running freely all over the place now), Comfrey, redcurrant bushes, rhubarb, globe artichokes etc... Where possible I have been deep mulching with woodchips too.

This is just a base layer that you can buy bulk seed for. We're indeed going to be adding a bunch of other plants for which you can only get seeds in little packets or individual plants.

Plant N fixing trees amongst the fruit trees so you can chop and drop the small branches around the fruit trees. Lawton goes 9-1 N-other trees as support. black locust is inexpensive and very easy to start from seed.

Cj Verde wrote:Plant N fixing trees amongst the fruit trees so you can chop and drop the small branches around the fruit trees. Lawton goes 9-1 N-other trees as support. Black Locust is inexpensive and very easy to start from seed.

I am indeed doing this. The Italian alders (alnus cordata) were put in just for this purpose. I'll be posting another post with our preliminary design to get more tips like these.

Anyone have any suggestions on how to do the sowing though? Should I plow or not? Should I till once or more times?

At the minimum you'd want to remove the sod from an area around where each tree will go. If you'll mulch heavily enough it might suffice to just turn it under then kill the remaining grass with the mulch but putting cardboard or newspaper down as an added precaution might help. If you'd use a shovel, it really helps to mow it short first then rake the grass away (it can be put back later as mulch or buried as green manure but IMHO on top of the soil might be better.)

In my experience just tilling doesn't kill the grass and it will come back again. If it's to be a grassy field for grazing animals it might be ok, if the clover has time to establish before the grass gets too tall.

geoff lawton in his videos used chickens to kill off the grass prior to planting an area with trees and legumes. IMHO pigs work too, but you have to confine them enough that they really clear the area then move them on before they compact it.

Avoid plastic mulch materials - they work great for the short term but in the longer term just cause headaches. Ask me how I know this!

If you need to mulch around trees then just throw down a layer of cardboard and thick mulch material on top.

Are you putting in any swales?

Cj Verde wrote:Are you putting in any swales?

Didn't even know what those were. Just searched for it. Wasn't planning any no. The field slopes down from the place where all our water comes from (a mine and a large tank). So the top half of the filed is a lot damper.

Pedro - you haven't said anything about you climate and location. These will have a bearing on recommendations. Most people here add it to profile information so it is always visible.

Regarding Swales, they are great for getting trees established because they help build a reservoir of water in the soil. If your rain is consistent year round this may not be an issues, but even here in the wet UK we have dry spells in summer and end up irrigating. Swales are a cheaper and easier alternative to bore hole irrigation if they will work in your setting.

Location? (consider adding your location to your profile).

Michael Cox wrote:Pedro - you haven't said anything about you climate and location. These will have a bearing on recommendations. Most people here add it to profile information so it is always visible.

Right. We're in the north of Portugal in Marco de Canaveses. It should be zone 9.

Michael Cox wrote: Regarding Swales, they are great for getting trees established because they help build a reservoir of water in the soil. If your rain is consistent year round this may not be an issues, but even here in the wet UK we have dry spells in summer and end up irrigating. Swales are a cheaper and easier alternative to bore hole irrigation if they will work in your setting.

We have pretty dry summers. For the trees I'm planning an irrigation system just to get them established. We have plenty of water thankfully and have a bunch of drip irrigation systems already in place and know what works and what doesn't.

Gotcha - I was in Portugal last year, near Evora - lovely country, although crying out for some enlightened permaculture land management. So much bare earth and erosion, and that was before the weather got hot!

Your dry summer suggests that rainwater harvesting via swales would be appropriate. Worth looking into before you go much further, because they are much easier to establish before you plant your trees. I think you will be surprised at how cheap the earthworks could be to get done - heavy machinery hire isn't very expensive and they will work passively for decades helping improve your groundwater infiltration and trapping sediment and mulch materials.

Pedro, I am sorry to say that I do not have any suggestions with regard to your question, which is what is the best way for you to prepare the field for sowing your pasture mixture.

As I understand it, you have already planted many of your trees, you are not planting grass around those trees. You have an irrigation system in place for watering the trees.

What you don't have at this point is a good system for preparing the pasture area and sowing the pasture mix.

I say this in hope of highlighting the question that needs answering so that someone who does have good advice on point can chime in and help you out.

Michael Cox wrote:
even here in the wet UK we have dry spells in summer

We do

Michael, slightly off-topic, but do you have photos of your food forest?

Back on topic. I am wondering if it is even necessary to replace the grass and weeds in the field. It is my understanding that a damaged piece of land has a certain succession of plants which naturally progresses towards a forest. First you get your quick-growing weeds and grasses which cover the soil, pull up nutrients, and stabilize it to prevent it eroding. After some time, the soil is better conditioned and perennials and shrubs start to colonize, and the weeds die back a bit--most weeds generally prefer poor soil in sunlight; they've done their job accumulating nutrients and creating biomass, and the soil becomes rich enough for other plants which in turn out-compete them and shade them out. And the next succession is the trees and on to forest.

Now bearing in mind my practical experience stems from 3 months of forest gardening, and is based mainly on book-learnin'! But I think the grass and weeds which are already established in the field should remain so, if you want an open prarie-type space. It just seems like a lot of effort to remove one kind of plant just to replace it with similar plant, especially if they can both perform the same functions.

Galadriel Freden wrote:

Michael, slightly off-topic, but do you have photos of your food forest?

"forest" is a bit grandiose for what I have at the moment. I have a small conventional vegetable garden and orchard that I am experimenting with and transitioning over. I've got promising results and big plans to expand but it is still very much limited at present. When I properly sorted out (and am living a sensible distance from the land) I want to expand out to around 1 acre total, but over a period of a few years.

This year will be my first with some solid guilds in place (established last year) so I'm looking forward to seeing how they do.

We do ??

I live in Kent, on fast draining chalk... a week of hot weather and everything slows down/stops growing. Two weeks and plants start to suffer. On the plus side, you have lovely hills to walk in up there

Peter Ellis wrote:What you don't have at this point is a good system for preparing the pasture area and sowing the pasture mix.

I say this in hope of highlighting the question that needs answering so that someone who does have good advice on point can chime in and help you out.

That's exactly it. Thanks!

I have a friend who started a Forest Garden in Northern Portugal, on the top of his property, he's put in swales and is very happy with them.

Spent the day working the field. Burned off some old branches and broke down a pile of compost into several piles around the trees to mulch them. After that had a tractor come in and till the field. The original plan was to sow right after as tomorrow there's rain forecast. However the weeds were so tough we decided to let it rest for a few weeks, let the weeds come back and then till them again. It will also give me some time to improve the mixture I had bought. I want to add a red clover and some comfrey and borage. My bulk seed supplier is looking up the prices for bulk comfrey and borage and hopefully I'll have those seeds in a week or two.

Pedro Cr wrote:Spent the day working the field. Burned off some old branches and broke down a pile of compost into several piles around the trees to mulch them. After that had a tractor come in and till the field. The original plan was to sow right after as tomorrow there's rain forecast. However the weeds were so tough we decided to let it rest for a few weeks, let the weeds come back and then till them again. It will also give me some time to improve the mixture I had bought. I want to add a red clover and some comfrey and borage. My bulk seed supplier is looking up the prices for bulk comfrey and borage and hopefully I'll have those seeds in a week or two.

Hey Pedro, I am glad to hear you are trying something new with your land, I am sure in your climate you will have a very diverse forest in a good amount of time.
In one of my previous growing areas I started out just as you describe, basically till and then till again a few weeks later to make sure the slate is cleared. I did successfully remove the grass and weeds, but I think the soil biology suffered since things seemed a bit slow coming up in that area. If I were doing that technique again I would absolutely look at inoculating my seeds before sowing. I have had great germination from some inoculated red clover seeds I bought and it made me realize how much that would have helped getting a strong start in re-tilled soil.


Good luck!

Pedro, looks like you have gotten some good advice. I would highly recommend that you find the highest contour line on the pice of property you are planning this food forest on so you can plant your trees accordingly. Even if you are not planning on putting in a swale right now, you may want to later and it would be a shame to have to disturb the trees you are planting later on. The swale can be as simple as one pass with a double bottom plow. If you could upload a topo map ( not sure if they are available in your area) with the particular ace outlined I might be able to give more specific help.

Zach Muller wrote:If I were doing that technique again I would absolutely look at inoculating my seeds before sowing. I have had great germination from some inoculated red clover seeds I bought and it made me realize how much that would have helped getting a strong start in re-tilled soil.

Thanks for the tip. What do you mean by inoculating the seeds? Do you mean inoculating the field with nitrogen fixing bacteria (what I found searching online)?

Amy Woodhouse wrote:Pedro, looks like you have gotten some good advice. I would highly recommend that you find the highest contour line on the pice of property you are planning this food forest on so you can plant your trees accordingly. Even if you are not planning on putting in a swale right now, you may want to later and it would be a shame to have to disturb the trees you are planting later on. The swale can be as simple as one pass with a double bottom plow. If you could upload a topo map ( not sure if they are available in your area) with the particular ace outlined I might be able to give more specific help.

Our whole farm is built in levels each with a support wall. It's basically a staircase on a slope. Now each "step" is not itself flat because the traditional way to irrigate is to make the water run along the ground. We've now invested in a complete system of plumbing all around the farm and can get water from a pump or just with gravity to any point in the farm. Our water source is a horizontal mine. Basically a tunnel in one of the steps that goes level into the mountain. At it's lowest the mine produces 15,000 liters of water a day. So far (for the last 10 years) we've dumped water away all through the year. We have 7,5 acres of which only 2 or 3 need irrigation. The rest already has a natural mix of forest that we've been making richer with different kinds of trees.

The field in question is pretty simple. It gently slopes down and has the mine opening and main tank at the top (east side). So the top tends to be water heavy. We've planted the alders on the north east corner as they are water tolerant. We planted the robinias in the northwest corner as it's drier. We will now be adding the additional (shorter) trees south of these to make sure they all get good exposure.

The field itself is known to be very water heavy. The supporting wall has once collapsed because of it (a long time ago). Since we're now using the mine water better instead of dumping it all on the ground that shouldn't happen again. Given this context I'm not really convinced swales are a good idea. The staircase structure of the farm already does much of the same job and we can easily create damper areas by just running a gravity fed irrigation tube.

So your land is already terraced. Seems like you do not need swales. Regarding inoculation, the actual seeds get treated with the bacteria before planting.

Amy Woodhouse wrote:If you could upload a topo map ( not sure if they are available in your area) with the particular ace outlined I might be able to give more specific help.

Here's a topo map of the field in question.

http://i.imgur.com/DDmiV6E.jpg

If you can't make out the lines/numbers the field has a 3m drop over its width and then there is the supporting wall and the next field is 6m below it. The 3m drop is over a 50-60m width so there's <1% drop already.

Peter Ellis wrote:So your land is already terraced. Seems like you do not need swales.

My conclusion too.

Peter Ellis wrote: Regarding inoculation, the actual seeds get treated with the bacteria before planting.

I'll have to check with my seed supplier then. Right now I'm planning 4 grasses (2 clovers, ryegrass and fescue) as well as borage and comfrey. Would this apply to all of them? Does it apply in general?

One option: till and then plant a dense cover crop like buckwheat as a suppressant. Till that in before it goes to seed, then plant whatever you like.

Another option, as mentioned above, is just to let the natural "weeds" take over. You might also consider adding lots and lots of wildflowers... I've started incorporating them into my food forest and the rise in butterflies/bees has been impressive. Not enough work done with pollinator attractors and food forests, in my humble opinion. Diversity, diversity, diversity!

Pedro Cr wrote:

Peter Ellis wrote:So your land is already terraced. Seems like you do not need swales.

My conclusion too.

Peter Ellis wrote: Regarding inoculation, the actual seeds get treated with the bacteria before planting.

I'll have to check with my seed supplier then. Right now I'm planning 4 grasses (2 clovers, ryegrass and fescue) as well as borage and comfrey. Would this apply to all of them? Does it apply in general?

Pedro, the innoculation is with the symbiotic bacteria needed for nitrogen fixation by the legumes, so it isn't needed for the other types. In terms of buying, your supplier may be able to get the legumes already innoculated, or it may be something that needs to be done as an additional step. Innoculation cultures are commercially available - although I have no clue what is available in Portugal!

Here is a link to a small article about the bacteria. As for specific types there is another article here with more detailed information about types and techniques. I have only ever used pre inoculated.

I remember seeing a video of Geoff Lawton where it showed him inoculating his legume seeds in a bucket but now I cannot seem to find it, anyone know which one I am talking about?

Zach Muller wrote:Here is a link to a small article about the bacteria. As for specific types there is another article here with more detailed information about types and techniques. I have only ever used pre inoculated.

These are awesome, thanks. Need to go and find the bacteria now. Apparently I'm looking for Rhizobium trifolii.