The more organic matter in the soil the better it retains moisture. Each 1% of organic matter in the soil will retain 168,000 litres per hectare. That’s of course hard to visualise. What it means is 4 cubic meters for a standard 10 pole allotment or 14 kilos per square meter. So 5% organic matter in the soil will hold 70 kilos of water per square meter. Substantially more than the body weight of a model like Kate Moss.
Sheet Mulching is a technique useful in converting grass or flower beds into productive ground. We are using it as a technique for building our forest garden by using it as part of the sequence towards perennial planting. Basically you cover the ground with something organic and rottable that the weeds can’t get through. Old Carpets and rugs made from natural fibres like cotton and wool are good as is cardboard.
A quick overview of why plants can benefit from a cold snap. It’s kind of like a board game where the aim is to accumulate degree days. So one degree day is one day spent below a given temperature which varies from plant to plant. 1 day at 6 degrees below is worth 3 days at 2 degrees below. When the critical number is reached then the plants will move onto the next phase in the cycle. This tends to be a feature of long day plants.
This whole approach to designing a functioning ecosystem from day one is something that we really should be looking at more given that I’m beginning to suspect that what we think of as conventional farming is uncomfortably dependent on cheap oil.
These leafy vegetables really cross over between annual and the perennial approach to gardening beloved by permaculturalists. As long as you keep picking them they remain vegetative – sorrel does that too and its a really useful thing for intelligent gardening.
The remaining minerals a plant needs are Sulphur plus a string of trace elements. These are Iron, Manganese, Copper, Zinc, Boron, Chlorine, Molybdenum and Nickel. Deficiency of any of these can lead to disease and a few trace elements are toxic if present in excess. Generally speaking these are not detectable by the kits available to amateur gardeners and in practice even commercial growers send samples away to be tested professionally.
Getting at the details of what Magnesium and Calcium actually do are quite tricky because most gardening books tell you what happens if they’re not there and leave it at that. So after a bit of sleuthing this is what we came up with. Calcium binds the cell wall together and Magnesium makes Chlorophyll work. Plus the come free with the deal when you lime with carbonate to fix the soil pH.
For those who like doing things for themselves, one way of feeding the plants is to make your own liquid fertiliser. You can do this quite simply by using deep rooted plants like comfrey and nettles. These not only are high in potassium and nitrogen but also concentrate trace minerals from the subsoil. It’s really quite easy. You can buy one or more of those 50/75 litre waterbutts they have in B&Q or Homebase plus a tap for them. Fill it up with freshly cut roughly chopped comfrey and nettles (we sometimes put thistles in ours too) and then fill it up with water. Leave for 3-6 weeks – then dilute and use
Video to demonstrate what you need to do to test your soil with a soil testing kit. Covers pH and Nitrogen, Potassium and Phosphate.