Soil fertility options
• Winter broad bean plants can be dug back into the soil as a green manure crop. Broad beans are nitrogen-fixers (you can see little white nitrogen-fixing nodules on their roots). Chop these plants back into your soil with a sharp spade to build organic matter, improving nitrogen and carbon levels.
• Apply mulch and wait for several weeks before planting heavy feeders from the brassica family.
• Enrich your soil by digging in basalt rock-dust for minerals, then dolomite or lime to raise the pH. I often mention the Environmental Fertilisers range, as its organically certified Natures Organic Fertiliser has all the goodies, including beneficial bacteria to boost the life in your soil.
• Alternatively, you might add sheep pellets and a little blood and bone and you should have your bases covered for a bounteous summer crop. Skip the lime on your potato or strawberry patch as they prefer a lower pH.
• Hopefully you're making your own compost in some shape or form. All above-ground crops benefit from the addition of compost at planting time.
• If you have a worm bin, mix vermicast also known as worm poo) into rainwater and use this slurry when planting leafy greens and brassicas. Use diluted worm juice as a liquid feed as they start to grow.
• Alternatively, trench fermented bokashi under at least 20cm of soil and plant heavy feeders in that spot in several weeks' time. You won't need to use shop-bought nitrogenous fertiliser in your garden if you've got good supplies of home-made compost, or rich fertiliser from a bokashi bin or a worm bin.
Rotate your crops
For the most part, vege gardens require nutrient-rich soil, but crop rotations are a good idea as certain vegetables such as root crops have different needs.
Establish a rotation for your garden to match your plant requirements with fertility levels in the soil. It also helps reduce pest or disease build-up if members of the same family are not planted in the same spot year after year.
If you've already planted your vege garden, not to worry. Just keep a diary and draw a diagram as a reminder for next year of where your crops are planted. In smaller gardens, mixing a range of plant families together can help reduce pest damage, as they'll have a harder time finding their preferred plant.
Vege plot rotations:
Divide your garden into four plots. Each year rotate one vege family to the next plot.
Start:
Plot 1: Legumes (beans, peas), plus members of other families such as tomatoes, peppers, zucchini and pumpkin. These plants like plenty of compost. Intercrop corn, beans and squash together.
Plot 2: Brassicas (cabbage, broccoli, Chinese greens, radish, etc). These plants like rich soil provided by the legume family. Intercrop with the lettuce family.
Plot 3: Root crops (potatoes, carrots, beets). Intercrop carrots with beetroots and the onion family. Onions help mask the smell of carrots, deterring the carrot rust fly.
Plot 4: Fallow bed - grow a carbon crop or green manure to be dug back into soil. Bulk seed is available through kingsseeds.co.nz
Then start again (in the same order).
When to plant
Most heat-loving crops can be planted for your summer harvest right now. But if you have a raised bed you're probably well ahead and have plants in already, as this soil is usually warmer than soil at ground level.
Old-timers used to see if their soil was ready for planting by testing it with a bare bottom. If it was cold, then planting could wait. Veges will race ahead if the conditions are just right.
Sowing seed and growing your own vege seedlings for transplanting is the most economical way to grow food.
Get your garden beds prepped this week, then check out next week's column for tips on seed sowing.
• Next week: Space-saving solutions for food growing
