“A honeybee would have to fly around 100,000 kilometres and visit over a million flowers to find the nectar to make two kilos of honey. As it happens, they can only manage about 800 kilometres before they exhaust themselves and die.”
Niall Edworthy, The Curious Gardener’s Almanac (2006).
It is your very last call for sowing green crops if they are to be of any value this winter. Green crops are a time honoured method of conditioning soils. They are a particularly useful tool on heavy soils. These can compact badly when left bare through a sodden winter and then turn to concrete when they dry out again. The roots penetrate the soil and keep it open, making it easier to work when it is time to dig again.
Green crops also slow the leaching effect of winter rains. They take up nutrients which would otherwise be washed away and release these nutrients in the spring when dug in to the soil. Think of them like a nutrient bank.
Recommended practice is to dig in green crops two to three weeks before you start replanting in spring – which means about the beginning of October. If you are not using all your vegetable garden in winter, green crops also look a great deal tidier than a forest of weeds and seedlings. Logic says that forest of weeds will also act as a green crop but you only get the full benefit if you dig the entire plant in later and you don’t want to be digging weeds with seed heads already formed into your ground.
Lupins and mustard are other winter options. Lupin is good for adding nitrogen. Mustard is reputed to kill undesirable nematodes by a form of natural sterilisation. Oats are the quickest growing option and will germinate the fastest. At this late stage, they are probably the best choice.
First published in the Waikato Times and reprinted here with their permission.