We have been working to implement the basic design for our food forest and sure, every place is different and can present different challenges, but anyone starting from scratch like us will sooner or later have to confront weeds.
I really want to believe that weeds are a resource and are nature’s way to protect exposed soil etc., but in practice weeds are also a real problem, especially in a wet tropical climate. If they are not dealt with, they take over very quickly and can smother new seedlings, invade vegetable beds, etc. It seems the best one can aspire to is to find ways of slowing them down somewhat, while waiting for a tree canopy to establish, which will, eventually, create a natural mulch layer and deny the weeds the sunlight they need to flourish.
Dealing with weeds can suck up a lot of time and energy (and petrol) and, as it looks like every day a few people somehow stumble across this blog, I thought it could be interesting to share my little bit of recent experience on the subject.
We do not use any weedkiller and in a ideal world would try to minimize the use of the brush cutter, but unfortunately not yet, there is no way round it. But we are implementing a number of different ideas that will hopefully help us slowly to reduce the use of petrol based machinery. The following are a few ideas we are trying to work with.
Pinto peanut. (arachis pintoi) Very useful, but very invasive plant if left unchecked. I have used it in many places that already had a mixture of random grasses and weeds growing, I tried both growing from seed and transplanting cuttings, which is more labour intensive, and I would recommend the seed method. At the beginning it will look sparse and will require regular watering to establish, if planted in the dry season, but it will spread relatively quickly and overcome almost everything else, it is also a nitrogen fixing legume. Best avoided close to vegetable beds or fences.
Beans. Most beans will grow very quickly and provide rapid ground cover, most types will grow back a couple of times or more if cut back, the resultant biomass is rich in nitrogen and can be used pretty much anywhere, we have recently planted ginger, galangal and turmeric and the cut beans should become mulch for them. This time we have used cow pea (vigna unguiculata) very easy, very fast. Needs to be cut back after a month or so.
Lemongrass and/or citronella. We have tried planting in rows in areas where trees are becoming established, they tolerate grass around them and lemongrass can be harvested and sold easily. When a clump is lifted there is no great loss of soil as the roots are very shallow, the area could then be mulched and turned into a veggie bed, or can be planted as lemongrass again. Best of all, they need no attention and they help keep insects away, so they seem to be good around new trees.
Pigeon pea and sunn hemp (cajanus cajan and crotalaria juncea) are two fast growing legumes that we use also repeatedly, sunn hemp is easy to remove when sown in a food forest situation and if cut back will grow back once, somewhat weakly. Pigeon pea grows into a small tree that can be chopped back repeatedly. Between the two I prefer sunn hemp, it can be seeded very easily by broadcasting, and can be dug in the soil quickly at time of flowering, we have used it also as a green manure crop, prior to rice planting. One or two pigeon pea trees should be left to grow for seed, it is very labour intensive to collect sunn hemp seeds and definitely cheaper to buy a sack or two.
Water hyacinth can be used as mulch, better with cardboard as well. We have it growing in two ponds and regularly harvest it for this purpose, it grows back very quickly, I think it has a high nitrogen content. It dries quickly though and needs to be used to a depth of at least 30cm to be of use.
Malay grass. We bought some to establish a small bit of lawn in front of the house, on bare soil that was landscaped around a newly dug pond. It’s very tidy and easy to manage, very little grows through it and in our climate it does not need watering to survive. We are fortunate here that the surrounding forest provides early morning moisture almost all year round, I am not a lawn person and so I let it grow and only cut every six months or so. It could be a good option for a vegetable garden border or path, as it spreads quite slowly and tolerates traffic well.