For general advice on how to grow brassicas and which ones to grow take a look at the chapter growing leafy (and flowering) brassicas all year round. This chapter is just about growing brassicas in the hungry gap, which is much more challenging, but also provides some great opportunities for experimentation. More importantly it's a great way to get some wonderful food at a time when most people have very little to eat off their allotments!
The hungry gap run's from April to early June and it's considered the leanest period of the gardening year in the UK. Since Debbie and I are self-sufficient in veg and we wanted to eat fresh food all year round, rather than eat from the freezer (we don't like frozen veg) it was our first real challenge. Based on our experience over the last few year's I think we've got it sorted.
The challenge with brassicas is that they nearly all want to go to seed in April and they've almost all gone to seed by May. While you can eat the flowers, they tend to be best in early April and reduce in quality by May. The winter cauliflowers, cabbages, calabrese, kale, brussels, kalettes etc have all finished, all that's left are the spring cabbages and purple sprouting broccoli.
The traditional approach to the hungry gap is to rely on spring cabbages and purple sprouting broccoli. While we think this approach is a good start, it's not enough for us for a few reasons:
Over the years we've discovered that it's possible to have a much wider range of brassicas available for harvest in the hungry gap. We achieve this through a combination of over-wintering small plants, growing under cover, starting plants early, unusual planting densities and perennial varieties.
In addition we try to make sure that optimising for the hungry gap doesn't compromise our winter or summer harvests, this requires some careful attention to timings and inter-plantings.
Everything I describe in the next section can be achieved with, or without, grow lights. When I mention timings, I will provide both. If your gardening budget stretches to grow-lights I really recommend them though, they make growing for the hungry gap so much more fun and predictable. For more information on grow-lights check out the chapter Growing With Lights.