Brassicas are a group of vegetables that are hungry for nutrients, so they should never be grown in the same spot twice -so practice crop rotation. Our health is directly linked to the health of the soil - if the nutrients are not in the soil ( and some countries like Australia naturally have poor soil to start with) and if the Ph is not correct the plants will not be able to uptake the nutrients. The very first thing to do even before setting up your vegetable garden is make 3 compost bays 1.2m x 1.2m and start making compost. Home made compost is the most superior soil to anything you can buy. I will explain how to make compost in another post. You must add plenty of compost to the soil 1 bucket per m2 dug through is good.
Brassicas like an alkaline soil so it is important to do s soil test or if it is a new site you are planning to convert into a vegetable garden you can test the soil ph yourself, the kits from the hardware store or garden centre are not expensive or you could organise a professional soil test which does cost more but it is very thorough and specific. To change the soil to a more alkaline PH range for the brassicas I add dolomite lime following the directions on the bag for the rate per m2 in the area you are wanting to grow brassicas. Dolomite lime is good because it also contains magnesium and calcium. If the soil is very acidic you may need to apply more but test the soil first. You also need to add the natural minerals - not synthetic ones please! I use a ground up volcanic rock dust called Fishers Creek Rock Dust and add it twice per year. FCRD is a BFA registered product and it contains over 50 different minerals and helps to strengthens the cell walls in the plants and makes them more disease and pest resistant.
I also add composted pigeon manure but you can use chicken manure - but be careful and enquire what chemicals the farmer has used - organic is best as some poultry manure contains pesticides, hormones, herbicides, GMO Soy, and please do not use fertiliser that comes from factory farming as you will unknowingly be perpetuating extreme cruelty to animals. Always compost animal manures before use. I dig a trench a spade depth wide and 1/2 spade depth deep and add all the nutrients the plants need and dig it through. I then plant rows of brassicas either side of the trench with a depression in the soil so the water penetrates deeply. Placing the nutrients a spade depth into the trench encourages deep roots and the plant will access the food once it is big enough and ready. Water deeply, in summer you will need to water every second day and in hot weather, every day. Mulch the vegetable garden with lucerne, spread it out about 10cm depth. I t will break down and add humus to the soil.
Kale, collards and mustard greens are not readily available in the shops to buy or at the garden centres as seedlings but it is easy to propogate from seed. Mid - end of summer is a good time to sow directly into the soil and get it growing before the winter arrives (this is particularly important is cool climates). In the cooler weather, you can sow into punnets or trays and germinate the seed in a 4 tier mini propagating house which are now available at hardware stores and garden centres for around $40. Sow into propagating mix and keep damp, gently transfer into the garden when the plants are 12cm high. A good seed propagation mix is 50% washed sand and 50% peat.