August can be a frustrating month, as a reawakening of daffodils and other early spring bulbs can lead us to think that warmer weather is about to arrive.
However, the last week’s succession of bitterly cold weather reminds us that spring is still more than a few weeks away. It is not time to get the main spring planting of vegetables underway yet. The best we can do is keep an eye on the soil in the vegetable garden and make sure that it is ready.
That can be tricky, especially when we have a wet winter like this one. Most soils are very moist now, and it is probably best not to trample over them if it can be avoided it. I still use the old gardener’s trick of keeping a broad plank in the garden shed and bringing it out if I need to walk on the plot or even kneel on it to weed.
I like to work some lime into the vegetable patch if I can in early spring because it helps keep the pH levels up for those crops
that need it. It is especially important if you use a lot of
compost [and I do] as that generally has a lower pH. If you are using lime, bear in mind that the finer the consistency of the powder,
the quicker it will be released into the soil, so lime flour is great if you want a quick hit to the pH. On the other hand, if you are looking for a more sustained slow-release effect on the soil, use coarser agricultural lime. As well as being more beneficial in the long run, it is also cheaper!
One group of vegetables that need a higher pH is the brassica one.
It helps them grow better and provides a little protection against club root, a nasty disease that can decimate brassica crops.
It is remarkable that the many brassicas we grow in the vegetable garden mainly arise from one species of plant – the European wild plant Brassica oleracea. No one is quite sure exactly when it was brought into the garden from the wild, but it is certain
that it occurred at least 1000 BC and we know the Romans enjoyed eating them, often seasoning with olive oil and vinegar.
When first brought into the garden it was a loose-leaved vegetable, growing in a similar manner to silver beet. It was not for many generations that the tight, drumhead varieties we are more familiar with today were developed.
There were other remarkable changes in the way people ate this vegetable. In southern Italy, clever gardeners began to select varieties for their flower heads, concentrating in particular on varieties that formed a crest of buds.
They called this broccoli, meaning “the flowering crest of cabbage’; and it was soon a popular vegetable, sometimes called Italian asparagus.
Modern types of broccoli have large terminal heads of flower, with some much smaller secondary heads which are scarcely used in commercial cropping. There are other “sprouting broccoli” which have smaller heads of flower on many thin stalks and can provide a longer harvest for the home gardener.
Other ancient gardeners started selecting brassicas with a large flowerhead stem – the Italians called them “cavolfiore”, literally cabbage flowers. Of course, these are what we now call cauliflowers, usually found with white heads, but also available in orange and purple. There are also green forms, usually called broccoflower which are just forms of cauliflower rather than hybrids, as the name suggests. Oddly enough, the best known of these broccoflowers is actually a green-yellow broccoli called Romanesco, famed for the vibrant light green colour and the fractal patterns on its flowerhead.
Brussels sprouts are another, perhaps less popular, variant on the cabbage theme. Horticultural historians believe these originated in ancient Rome, but did not become very popular until much later – the first recorded entry of their existence is in the late 1500s when they became popular in parts of the Netherlands – and it is clear from their name, in Belgium.
Although shunned in many parts of the world, loose-leaved cabbages, also known as collards, are popular vegetables in some locations. They are a staple of Southern USA cuisine, and popular in some parts of Africa, as well as Portugal and Brazil.
Other “cabbages” include kale [which has been cultivated longer than cabbage], broccolini, kohl rabi and even the popular winter bedding plane, ornamental kale – which is also edible!
Although the cultural needs of these various forms vary slightly – some do not like growing in the heat, while others cannot stand the cold – generally, they prefer good organic content, good moisture and a relatively high pH. They do not like being grown in the same ground year after year – it pays to rotate where you grow brassicas as they will perform better, and they will also be less susceptible to club root.
