Suburban Sue

Brassicas - Green, good for you and erm..tasty as a yeast extract for some!

For the last few years I have tried growing a few brassicas - I was reluctant at first as they can take up a lot of room and I have only had four available raised beds. I have been slowly extending into other areas of the garden using potatoes as a first crop to break up and cover the soil to suppress weeds. Unfortunately local badgers have had a field day - as my colleague described it ‘ they have stumbled on a motherlode and are now very happy badgers!’. This has left some previously allocated areas free from a crop once I’ve tidied from badger armageddon! 

I have had some success with brussels sprouts, kalettes and early purple sprouting broccoli but planning the beds plus newer extensions have taxed my brain when it comes to crop rotation. The aim is to not plant brassicas in the same place but leave a gap of 3 years between crops. This is to reduce clubroot occurrence in particular. So yesterday when my brother in law sent me some of his spare cabbage and cauliflower seedlings  - where to put them?

Brassicas are a genus in the Order Brassicales, Family Brassicaceae, formerly Cruciferae and for the gardener are often thought of mainly in terms of cabbage and mustards. Under the Family name are a large number of Genera that we are familiar with in the flower garden such as aubrieta, wallflowers and nasturtiums. Some Genera contain other vegetables we use such as rocket, sea kale, radishes and swede and foragable weeds such as bittercress, so bear this in mind when planning crop rotation. More commonly the Brassica (Genus) includes different species giving us cabbages, cauliflower, broccoli, kohlrabi, swede, turnip, choy sum, pak choy, komatsuna, and kale. They are important in a varied diet providing vitamin C, vitamin K, manganese and soluble fibre as well as being available throughout the year. 

Some people dislike brassicas due to the sulphur compounds released by chewing and cutting the vegetables, this is more common in children. My children were divided into two factions - those who ate them happily and two who didn’t. One Christmas when asked to stop jumping up and down on the bench or he’d be given more sprouts to eat resulted in more wriggling, not less! As adults, however, this dislike usually fades, which is important as they provide a good source of folic acid, needed for creating healthy red blood cells and also in pregnancy to ensure the good neurological development of the foetus which can otherwise cause life limiting problems such as spina bifida.

Brassicas need careful management in the vegetable patch as they are subject to a soil borne micro-organism giving rise to a club shaped root which stunts the plant by reducing uptake of resources. Once established this can stay in the soil for as much as 20 years. 

Prevention of clubroot is usually with crop rotation, liming to give a pH of 7 or over, starting off with a sterile compost for seed and growing the plants until well established, water management as well drained rather than overwatered soi prevents the organism moving through the soil so easily.

Some brassica types are happy germinating in the cooler temperatures of early spring. Summer and autumn cropping varieties are sown indoors in Feb - April and planted out in April where they grow on to produce an early harvest. Others are sown later outdoors. Brassicas need a long growing season so some are sown August September so they germinate in the warmth but grow on in the cooler autumn weather. If stressed by heat many brassicas tend to bolt.

They may be sown indoors and hardened off before planting out or grown in a nursery bed before planting out.  - often after main crop potatoes depending on variety.  As they grow they usually need protection from pigeons and staking or firming in so that mature plants of brassicas such as Brussels sprout and kale are not dislodged by strong winds. Covering with horticultural fleece will provide a protection from cabbage white butterflies and pigeons.

Many of the oriental vegetables used to extend the green leaf season are also brassicas - plants such as Pak Choy, Chinese broccoli, Chinese Kale so include them in your brassica rotation. They are a useful crop as can be sown later than many of the classic British brassicas and are also winter hardy.

There are many varieties of brassica for it’s possible to plan brassicas to give you leafy greens throughout the year. Kale particularly is a long lasting crop that is also one of the more nutritious brassicas and also easy to grow. Trying both a curly kale and a flatter leaved variety can give a bit of variety to the menu too.

So back to where to put those extra plug plants? I have one spare plot which was the most recent to be taken into cultivation but then completely ‘badgered’. The plan is to use old compost and chicken pellets under a weed control fabric and plant them through that. I have recently acquired some slug wool and I think I have some spare horticultural mash to cover them too. Failing that it will be plastic bags on sticks to keep away the pigeons. So fingers crossed that something will come from nothing.