Very steep slope with no top soil left on it

Hi again folks,

I'm currently on a half-acre suburban fringe site. Along the length of my property is a narrow strip of land that slopes down towards my site at about a 60 degree angle, give or take, that was put in when the council built up the land next door to make a football oval about 30 years ago. All of the top soil has long since washed away, and now all that's left is rock-hard clay. There are wild blackberries growing there (a declared noxious weed here) as well as quite a few trees (all of which are on the declared environmental weed list). The slope faces west. And, er, it's not actually my land. It technically belongs to the council, although they don't follow their own rules regarding the elimination of noxious weeds and don't do anything to maintain it. I think they've sort of forgotten it exists, since you can't see it from the oval, or from anywhere else except my property.

Aaaanyhow. I'm pretty sick of the weeds there invading my property, and at this time of year it's a massive fire risk (I'm in Australia). So I want to clear out the scrub and do a bit of guerrilla gardening there. Which is all well and good, except there's no topsoil left to plant anything in.

Now I realise that I would have to put in some sort of terrace system so that any future top soil doesn't wash away too. My two main issues are: a) I don't want to spend big bucks since it's not my land, and the council might feel like picking a fight with me about it at any time in the future, and b) this strip of land is so very steep and so very narrow that I don't think I'd be able to get any/many terraces with a decent width on it. Also there's no access for heavy machinery, and I don't want to dig into the slope much anyway - it's stable at the moment and I don't want to mess with that!

Does anyone have any ideas in how to deal with this?

The only halfway decent idea I've had so far is to put in long rows of hay bales all along this strip of land, then use some scavenged corrugated iron and rebar rods to make a 'retaining wall' in front of each row of bales. I don't know it this would work though.

Any suggestions most welcome!

Marie,

It is always nice when one get's free use of neglected land. A pair or three goats should make short work of the weeds, and won't mind the slope. Keeping them off the pitch might be a fun challenge...

Rather than growing something in the soil what about using the slope to support a vine crop? Something like hopps could be grown up (or down) the slope. Ask around with the craft brew crowd or micro breweries what hopps they have trouble getting. Vining tomatoes will also grow down slope. But I would be concerned how one would harvest tomatoes on a 60 degree slope.

Clover might be another good idea. Let the legumes improve the soil while out competing weeds. No disruption to the stability of the slope.

Ahh goats. Yes. I'm always on the lookout for someone who's willing to lend me their goats! Failing that though, I'm happy to brush cut and just chop and drop.

Regarding cover crops: I'm all for it, and anything that would improve that hard claypan would be a blessing; but there's quite literally no topsoil to grow them in. How would that work? Perhaps I could make some seed balls or something? I'm not quite sure. Also I have no idea what might out-compete wild brambles. They're a noxious weed here for a reason!

Hmmm.

But you're quite right, it's not an easily accessible space, so anything growing there would be primarily for the wildlife, and secondarily for human consumption - but the human food would have to be something that you don't have to harvest often. A once-a-year harvest would be ok, but I don't think I'd want to clammed up the hill every day to pick my salad veg

But Jack, I do like the idea about using the slope to grow a vine crop. I could lay some pallets up the slope, hold them in place with some rebar or something, and grow passionfruit? Melons? Pumpkins? Cucumbers? I don't know. But I like your thinking.

How about putting that row of hay bales along the bottom of the slope on the edge of your property, like a temporary swale berm? Then as you chop weeds on the slope, all the fertility that washes downhill will get captured above the bales, where you plant your vines (something that, like pumpkins, will climb all the way up the slope and root along their length if they find soil.

Meanwhile clover will grow on almost pure clay. I would create a bunch if micro-terraces (flat scuffs into the slope the size of my mattock blade, maybe three inches wide and an inch or two cut into the slope?) and seed the clover there. It should spread and make its own soil in time, which your vines wil benefit from either in place or when it washes down to your line of hay bales.

Since it's a difficult space to access, it will also be difficult to check on ripeness of crops. Something that is harvested all at once when mature and something that will ramble to fill the space would simply matters. Luffa gourds could be rooted at the base of the slope and in a few good spots on the slope. At the end of the season, the vines can be pulled down. Most of the gourds will be dragged along.

If this was land I wanted to use for any sort of food crop the first thing I would do (after getting those nasty blackberries and other noxious things down) is drive some stakes and lay down some wood above those stakes to form swales. Swales don't have to be huge, just 12cm of height will get things going quite well. Above each of these wood swales you can start placing things to make compost or leaf mold. As things start to deteriorate, you will be able to begin planting items you want to grow.

As things get better you can add more compostables to rot down and provide more growing space.

By doing it this way, you will have little money involved, mostly time, that way it won't sting very much if the council rediscovers that strip of land.
An alternative would be to approach the council and see if they would Quit Claim (type of Deed) that strip to you. Mention that it is steep and the bottom is against your property, then mention that all the run off that comes down that slope is a bother you have to deal with since it deposits clay onto your property that either has to be moved or somehow incorporated into your garden soil and they just might let you have that "useless strip" of steep land.

Don't you think "weeds" are there for a reason? Like pioneer stage, creating top soil and breaking clay soil?! You can speed it up, but i doubt it will work with vegetables, stronger already present pioneers will come back anyway. The potential of "weeds" is to cut them down and make bio-rolls on countour and plant strong perennials.

I think that the slope is the buttress that holds up the playing field. If it were deeded, they would have to ensure that it could never be excavated. This would put the council in the position of having to force the new owner's hand if there is a problem. A lease which protects the field could work.

Olives and some nuts can thrive on steep ground. Tarps could be laid out at harvest. The crop would slide in your direction. Growth that strengthens the bank against erosion is appropriate.

Personally, I love blackberries and would probably enjoy cobblers from them but if not I'd be tempted to try pinestraw mulch with blueberries at the base of it. You say a half acre with a narrow strip of slope so I'm guessing it isn't a large area. If pinestraw is available for free, all the better.

Hi all. Thanks for the great suggestions!

Just to clarify, this strip is probably around 80 metres by 10 metres or so. So I guess it would be almost a quatre acre all up, but it's totally unusable for anything other than a bit of forest. I have asked the council a few times if I could take over responsibility for managing the weeds and replanting: no dice. They didn't even respond to my phone calls or emails about it.

Also, the blackberries aren't really edible. Well, they're edible but not very tasty. And there's not many of them. And yes, I do understand the role that pioneer species play in regeneration of degraded areas. Unfortunately most of the species growing there are a) terrible fire hazards (this is a very big deal in Australia), and b) skin irritants that trouble my dogs and myself (particularly English ivy and tradescantia). Since the strip is only 10 metres from my house, I think these things are worth considering. I'm trying to establish mature systems on my little lot but with so much pressure from these super invasive species on two sides of the property, it's pretty difficult.

So. Now I've explained all that, I hope we can move on a bit! I really like the idea of straw bales along my fence line, and the metal stakes holding up boards or something. I was sort of thinking that the bales might help slow erosion/run off whilst simultaneously building some decent soil, but knowing what sort of cover crops might take to these conditions is awesome info too. Since it will just be me and my spade, it will be really slow going, and I'll have to do clearing/building/planting in little sections (if I try to clear the whole thing, then build all the terraces or whatever, by the time I get to the planting all the species I want to get rid of will have grown back!).

Now I don't think I'll really try to grow veg there. They'd be too hard to harvest. I think a little forest of small trees with fairly dense understory would be the best bet for max coverage and stabilisation.

But you guys have given me a really good starting point: start right next to my property. Lay down a swale/berm/row of hay bales. Pile debris weeded from that immediate area on the uphill side of this barrier. Mulch. Plant some soil building stuff. Start on the next layer up. This will be my basic method. Thanks for helping me lay out that little plan in my head!

Any specific recommendations or advice for this method will be very much appreciated! Or if you think it's a terrible plan, please tell me why!

"But you guys have given me a really good starting point: start right next to my property. Lay down a swale/berm/row of hay bales. Pile debris weeded from that immediate area on the uphill side of this barrier. Mulch. Plant some soil building stuff. Start on the next layer up. This will be my basic method. Thanks for helping me lay out that little plan in my head! "

This is a good plan you have.
Living in the States, I don't know if it would work for you but I use scarlet clover as a ground cover on my north slope to avoid all my dirt being washed down to my road.
This slope is right at a 45 degree angle and I am putting in on contour swales to slow the flow of the soil.
I build mine with downed trees then use leaves and chopped down vegetative materials from the slope to fill in the gaps between the logs.
Over this, on the up hill side only, I am spreading some red clay that comes from widening the road bed and digging the high side run off ditch to protect the road from being washed out again.

Good luck with your project.

I think I would go with the hay bales to protect your property from run off.
Then just continue to chop and drop along the slope and plant things that you
want on your side of the property line. If you spend time and money growing stuff
and they come through and have their way with it, you could find yourself unnessarily
worked up!

Thanks for explaining a bit more, now i understand your situation much more.

Idea i got is you can plant into hay bales?! When is your rain coming and how much usually? If you set up hay bales in a row, make some holes in them and fill them with compost and let them get soaked you could plant hardy fire proof perennials in rainy season or after it, i'm not familiar with you planting timing.

Choosing the right moment to plant is crucial.

I don't know about fire hazard wise, but i know sage is very dry tolerant, hardy and can grow in rock. Don't know if it grows there.
Mostly you need shrubs and trees i think, fast growing and if fire is a hazard, it's good they are fire proof.

Few square meters of nursery to propagate plants from seeds and cuttings (seeds and cuttings are free or very cheap) is in my opinion also crucial, you will need a lot of plants, so they can be planted in mass so they can grow as community and start strong.

Hehe Alex, yes, I would get worked up. I'm already a bit worked up/fed up as it is. If I had a huge patch of blackberry bramble and declared environmental weed growing on my property, I'd get a fine for the fire department and a council order to clear it every December. Apparently Council land doesn't catch fire. Hah.

And yes, I could just chop/drop a couple of times a year for the remainder of my time here. Since I'm only 30, that would be OK for the next 15 years. But when I get older, it would become a lot more difficult/dangerous to clear the slope. So my aim is to get something established there before my knees and hips start to go! Hah. And if I'm going to all that effort of clearing the land all the time, it would be nice if it could all be for something useful for us and the wildlife, you know? That's how I feel anyway.

Aljaz, planting IN bales is a brilliant idea! Thankyou! And Bryant, I'm glad to hear you're attempting this method too. Have you started on your slope? Pic would be great!

Hi Marie,

Yes I have started on my slope, Which by the way, is also covered in wild blackberries that are far to bitter to be useful for anything. Even the deer don't eat them, so what I've been doing is chopping them to the ground and planting a heavy crop of crimson clover to see if that will smother them out, so far it (and winter) has slowed them down quite a bit. If I can't control the canes that way, ripping them out by the roots is the next step. The slope has lots of dead trees that have fallen to the ground and it's these trunks and limbs that I am using to create the swales.

The procedure I am using goes like this; chop through brambles to get to a downed tree (most of them are already beginning to rot), muscle tree to where I want the swale to be, stake it in place with wooden stakes made from solid downed tree limbs.
Rake all the chopped brambles and leaves from up slope down to the new log swale and pack in against the wood.
Broadcast clover seed (mine is inoculated for a better start) rake over the seed and move on to the next downed tree to repeat the process.

I hope to get some photos when I get closer to having them all in place, we only get to work on the land on weekends right now and I have so much to do before spring arrives that I usually forget to have a camera with me.
I plan on putting up a thread about taking this land from raw to set up homestead when I have internet access on the homestead. Right now the only place I have it is at work and they don't let us do photos for personal use.

I do have some straw bales that we plant tomatoes and squash in, it works quite well. I have some portions of the south slope that will be getting two or three rows of straw bales both for water control and more raised bed use.

If you clear the slope you could pound good sized wooden stakes along the face and rest smallish branches to then keep organic matter from sliding down. Year after year of leaves, clippings and slash piling up there should give you something to grow in and once the roots take into the cracks it should all be much more stable. Could use a ladder against the slope to work on it without sliding down, if its as steep as you say.

As an alternative to food crops what about growing mulch material on it? Surreptitiously spread comfrey cuttings over the hillside then when you want mulch material you can cut and carry to your land, mix in some perennial n-fixers maybe by over seeding.

Thanks folks

John, I do really like the idea of putting some logs down and letting nature do the rest, but I am a bit worried about managing the unwanted species if I went for that slow, low intensity method.

Michael, I had not thought of using the space as a stealth mulch maker! That's a really good idea too!

I had been pretty hung up on the idea of growing trees and large shrubs there, because I wanted to create a bit of privacy from the oval, which looks down into our yard. Perhaps there's a way of incorporating the two...

I was thinking you would plant it with something not just put mulch on it and let it go to whatever grows wild, what you plant there of course you would need to figure out for your own needs.

Visual screen, stabilize slope, reduce intrusion of weeds... clumping bamboo? Jerusalem artichokes?

Oh John, silly me! I misunderstood.

Bamboo and Jerusalem artichokes are both excellent suggestions (for the bottom of the slope, at least! Too dry to grow anything up the top at the moment. I will eventually dig a swale up there, but not until winter - it's too hot for that kind of spade work at the moment, heh).

Marie van Houtte wrote:I will eventually dig a swale up there, but not until winter - it's too hot for that kind of spade work at the moment, heh).

If it is as steep as you say then a swale probably isn't appropriate - you might be better off with something like driving some posts in and putting some wooden boards on contour. They will trap silt and organic matter and don't need much digging.

Thanks Michael There's about 1.5-2 metres or so of flat land at the top of the slope, so I think a little swale up there should be OK, but there's no way I'm going to dig into the slope! I've sourced some short stakes and something called 'jarrah garden edging' which is just a thin untreated bit of wood I think, that I will put against the stakes once I've used up all the branches and sticks.

I also saw some stuff called 'concrete trench reinforcement mesh' or something, which is a strip of rebar type mesh that is a foot high and about 6 metres long. I thought about putting that up against the stakes instead of sleepers. What do you guys think about that? It's cheaper (although heavier), it won't burn or rot or get eaten by termites, and I think you can bend/curve it a bit to follow contour. Unfortunately it is painted bright orange. I'm not sure why...

Sorry, I know pictures of the slope would have been helpful, and I did take some, but I just looked like a wall of blackberry I'm afraid.