By Inke Falkner & Dominick ter Huurne
“We acknowledge and pay respects to the Dhurga people of the Yuin Nation, the traditional custodians of the Country where we live.”
In September 2010 my partner Dominick and I bought a 40 hectare property in the Southern Tablelands mostly covered with native bush. Initially we bought the piece of land as a weekend retreat, but we enjoyed ourselves too much and moved there from Sydney full-time in January 2016. We have been very busy building our house, but that’s another story. A few months after we bought the place we started to set up a food forest based on permaculture principles in one corner of the property that had been cleared and used for sheep grazing. The area is about 80m x 60m and on a slight slope. We wrote an article https://www.permaculturenews.org/2011/02/11/first-steps-to-a-food-forest-in-the-southern-tablelands/ about the first steps towards a productive and diverse food forest and received a lot of great feedback. So an update on our progress after five years will hopefully be of interest.
Swales to rehydrate the landscape
Swales are a useful tool to rehydrate the landscape. We first set up swales to catch run-off and plant fruit trees on the swale mounds. We settled for six swales about half a meter deep. After the swales were dug we realised that they were far too close together to effectively catch run-off and far too deep, too, for most rainfall events. Lesson learned.
So how have the swales been performing for the last five years? As expected they retain the water after it rains which then slowly seeps into the ground. Most of the time our swales only fill to about 150mm depth, but we’ve had a few heavy rainfall events (45mm+), which flooded the swales catching every drop of water. We were initially worried that the water wouldn’t infiltrate fast enough, but it seems fine. Only in winter when the soil is saturated and it is too cold for evaporation has there been water in the swales for several weeks. We haven’t had any problems with mosquitos and the soil in the swale bottoms doesn’t seem to be waterlogged. So far so good.
For the last couple of years we have started to use the swales to irrigate our fruit trees, when there is no rain for weeks or months. We pump water from our dam into one swale at the time for about an hour, which fills it about 150mm deep. It seems to work well and the water is where it is needed, close to the roots of the trees.
Another positive is the growth of reeds and grasses in the swale bottoms. This adds organic matter and habitat. After rain we can hear the frogs, even now in winter. We were wondering how we could accumulate organic matter inside the swales and sowed green manure and cover crop seeds a few times, but nothing ever came up. We also tried lucerne and chicory that grow taproots to open up the soil, without success. But maybe the timing was wrong because we spread a few bags of oat seeds thickly into one swale a few months ago, then irrigated the swale so the seeds soaked in water for a couple of days and now there is a thick mat of oats growing inside the swale, which when rotted down should add some nice organic matter. We also added horse and chicken manure so the nutrients can leach into the soil. Over time, hopefully in the not too distant future, there should be a nice layer of organic matter inside the swales providing additional nutrients for the trees.
A real food forest comprised of different plant layers
One of the key advantages of a food forest is the diversity of plants in the system that fulfil different, if possible multiple, functions in the community. Each plant occupies a certain niche and thus this ‘human-made’ ecosystem mimics a multi-layered forest ecosystem in nature. There should be at the very least a diversity of groundcovers, a shrub layer and a canopy/tree layer. However, due to its designed existence no system is exactly the same at any given location.
Ground covers – a diversity of ground covers would be ideal – clovers, lupins, lucerne and other legumes to fix nitrogen as well as some native ground covers. When we wrote the first article about five years ago, we had just sown and mulched our first green manure crop. The soil was freshly turned and aerated and the crop grew beautifully. Unfortunately we didn’t get around to cutting the crop before the wildlife got to it. They ate the whole lot in a few days and we were left with bare soil and stubbles. We sowed several cover crops afterwards, but they never really succeeded.
The soil started to compact and rain didn’t infiltrate but ran off. The soil became more or less like a hardened crust and any attempt to revegetate with green manure or cover crops failed. Not being there full-time obviously didn’t help. We also covered sections of swale mounds with cardboard, covered that with home-made compost and sowed the seeds into the compost. Initially the seeds germinated, but then they were eaten by wildlife or died without watering. Now, after five years, the entire orchard is covered with a mix of introduced and native grasses with a little bit of clovers and native ground covers growing in between. But mainly it’s grasses. We have even hoed small sections between the trees to get rid of the grass again and then reseeded it without success. The concept of ground covers being diverse sounds great, but how does one achieve on a larger scale this when grasses were the cover to begin with?
Shrub layer – we didn’t want to be too ambitious and aimed for three layers in our system: groundcovers, a shrub layer and a canopy layer i.e. fruit and support trees. We initially planted several berry bushes, rosemary, lavender and some native shrubs. The berry bushes are still alive, but are not doing much. Most of the peas and other natives died in the first couple of years, but the rosemary and lavenders are doing splendidly. Especially the early flowering rosemary is great as the flowers attract pollinators early in the season when some of the stone fruits are also flowering. So I’m looking for more early flowering, tough shrubs like rosemary.
The canopy layer in our system consists of a variety of fruit trees and Tree Lucerne (Tagasaste) as support trees, that we mainly planted to ‘chop and drop’(more of this later). When I look at the list of fruit trees we initially planted I have to laugh. There were many species that are frost tender, which could not cope with the fairly regular frosts we experience here. What has taken quite well are the stone fruit, the peaches, nectarines and plums in particular. The apples and pears have been slow to start off with, but are catching up.
There have been two main challenges in making this food forest a success in addition to the merciless climate here in this country – the soil and the wildlife!
Improving the soil
How do you improve the soil for a food forest on a bigger scale without spending a fortune? And by improving I refer to increasing the organic content in the soil to begin with. I’m embarrassed to admit that we haven’t done a soil test yet. Yes, I know this is the first thing one should do. We thought it sensible, however, to increase the organic content first and thereby stimulate soil life most importantly. From feeling and looking at the soil it is obvious that it contains very little organic matter. The soil has no structure and basically turns into dust when it is dry. In other sections it is loamy sand.
We started by applying our own compost we made from sawdust, coffee grinds, horse and chicken manures and various other materials we could get our hands on for free. Through another business of ours we have access to large quantities of sawdust which is why this forms the base of our compost. We started off producing about 1.5m3 per batch turning and watering each batch three times every 2 months. We soon realised that we couldn’t produce remotely enough compost to apply more than one bucket around each tree. So we up-scaled our compost production, which meant moving the composting area. We had to transport water in 200L drums to the new composting location which ultimately means that the new compost doesn’t get watered anymore after the initial set-up. We also had to reduce the amount of ingredients to those available in larger quantities, so the new compost consists mostly of saw dust and horse manure with smaller quantities of greens, leaves and chicken manure.
We applied about one wheel burrow of the new compost once or twice a year mainly around the newly planted fruit trees, but also between the trees. When we first applied the compost we thought it had completely decomposed, but it turned out that the sawdust was still fairly ‘undigested’. When we spread the compost it simply dried out and became water repellent. Most of it has been overgrown by now and hopefully is slowly being incorporated into the soil, but we are trying now to keep the composting heaps wetter and encourage microbial activity by adding “composting microbes” that we purchase in liquid form.
I have also found various sources of free wood chippings, which I have thickly applied around the trees. The chippings are a great source of organic matter as the timber is at various stages of decomposition, fungal threads are visible and lots of earthworms, which is great. The downside – I have brought in a few weeds and it is worthwhile trialling the chips on a small area first before bringing in large quantities. Some chippings are better than others.
Permaculture suggests “chop and drop”, which is very sensible. The mulch is grown onsite, chopped fresh and placed where it has to go. There is no transport, carting stuff around with a wheelbarrow or tractor and spreading it, which isn’t always easy if the mulch has to go on top of swale mounds. We planted at least one Tagasaste as mulch tree for every fruit tree. These trees must be the tastiest treat because the as soon as we planted the seedlings they were hammered by wildlife. It was phenomenal. No wire cage could hold the animals back. So it has been very difficult to get the young trees to a stage where they can potentially be “chopped and dropped”. Initially the Tagasaste were growing well, but then they slowed down and didn’t put on a lot of biomass. Also, the cold winters and frost here seem to slow them down quite a bit. The trees that made it provide some protection for the young fruit trees and can be lightly chopped. They will obviously provide more material once they are bigger.
However, there must be more suitable trees for us that can be used as mulch trees. One tree, that seems to coppice quite well and grows in abundance here, is the Black Wattle (Acacia mearnsii). Some people call it a weed because it is one of the first trees to colonise disturbed land, a pioneer. Black Wattles have popped up everywhere since the sheep have gone from our property. We have decided to make use of this readily available, fast growing biomass and we have “chopped and dropped” many of the Black Wattles growing in the orchard. The trees regrow and can repeatedly be chopped, they don’t have to be planted and cared for and the wildlife leave them alone, which is a big bonus.
Being a wattle, the trees will also fix nitrogen in the soil and therefore improve the soil. That is a lot of positives for a tree that is considered a weed. “Work with what you have” is our goal now – which local tree species can we use to improve the system? Having said that, we would like to plant some other wattles and native peas to include more nitrogen fixers in the system and plant more flowering species to attract beneficial insects. Another thought was to find some easy growing deciduous trees that shed their leaves and thus provide organic matter to the soil. We’ve noticed that worms love decaying leaves in particular. Any suggestions for other tree species that we could grow for mulching and that provide some other services would be very welcome.
Outsmarting the wildlife
Not possible! Full stop.
One of our biggest hurdles has been the wildlife e.g. wombats, wallabies and kangaroos where we are. I would like to emphasize that we purchased our piece of land because of the abundance of wildlife. We love having all the animals pass through, but the company comes at a price.
As we couldn’t invest thousands of dollars in permanent fencing, we opted for semi-permanent electric fencing, which has been useless. Yes, it keeps the kangaroos out, but certainly not the wombats and wallabies. Newly sown groundcovers are eaten, so are small bushes and the young shoots of planted trees. We lost most of our young trees in the first year to the wildlife. We individually caged the trees with chicken wire, which wasn’t strong enough to keep the animals out. Now we’re using smaller mesh wire to cage the trees and this seems to work better.
In our experience any trees planted need to be either individually caged with a small mesh wire, which is very time consuming and expensive. And again, how could this method be applied to a larger piece of land? Alternatively the whole area needs to be permanently fenced off, which somewhat defeats the idea of a food forest in our opinion and again is very costly. We haven’t come up with a solution yet, but meanwhile we are hoping for our trees to grow large enough that the branches can’t be reached by the very clever wildlife!
Lessons learned and where to go from here
1. Swales are useful – to rehydrate the landscape and for irrigation. One must go easy on numbers and depth of swales.
2. Diverse ground covers – important, but how to diversify if grasses are dominant?
3. Support trees for mulching specifically – a must in the system, preferably local species that self-seed and grow easily. Preferably different species to fulfil different functions e.g. protection, attraction of pollinators, nitrogen fixing
4. Soil test – should be done, ideally at the start, so one knows what to deal with.
This article is by no means a capitulation on the concept of a food forest or permaculture in general. On the contrary, the principles of working with nature and imitating nature very much apply. The key to success, however, is to utilise the species that are growing naturally or locally as best as possible. Also, depending on the wildlife pressure, in our experience the complexity of the food forest needs to be adjusted and perhaps simplified. And a diversity of groundcovers – well, this seems nearly impossible if one is blessed with invasive pasture grasses and an abundance of wildlife.
Friends have commented that our orchard would probably benefit from animals. This is true. The introduction of a couple of sheep or pigs would help to keep the grasses in check, would disturb and aerate the soil (in the case of running pigs) and would manure the orchard at the same time. Poultry e.g. ducks, geese and chickens would also be beneficial. And going back to nature – there is no ecosystem without animals. The interaction between plants and animals can be highly productive and beneficial (think African Savanah). So we will definitely look into getting some animals once we have settled into our new home.
So where to put your efforts for now? We have decided to concentrate on improving soil fertility and water retention.
You can get in touch and follow some of our activities on twitter @inkefalkner