I use a rating system to help me decide what to grow and it considers lots of factors, but the main ones are how tasty it is, how healthy it is to eat, how expensive it is to buy, how big it's harvest is, when it's harvest period is and whether I can buy it organically and if not how much it's sprayed.
Purple sprouting broccoli doesn't score that highly in this rating system, for one main reason it occupies the ground for a very long period of time, close to a year in some cases. The yield is way less than other crops that could be grown in that same time period. However it has a few things that commend it.
The main reason we grow it is because, almost uniquely, it provides a prolific harvest right through the hungry gap. If you are self-sufficient this is enough of a reason to grow it. Also it's extremely healthy and much better picked and eaten fresh. The leaves are also excellent and we eat these from about October until May. Finally it's hard to source organically and often sprayed.
<aside> 💡 If you are able to grow under glass or plastic, you can shorten the growing period and/or consider growing calabrese as an alternative. Many other brassicas flower in spring (kalettes, kale, Brussels etc, so you can eat their flowers too) and there are various short season rabbs, but they don't compare to purple sprouting broccoli.
</aside>
Purple sprouting broccoli gives a nice harvest over an extended period and as such it’s a better alternative to cauliflower and even calabrese. Varieties harvested in late winter give a much smaller harvest than varieties harvested in early spring, with mid spring varieties giving the best harvest. There are varieties for a summer harvest, but I don’t grow these.
Bearing this is mind we find that one plant/person is enough for most people, which - if you want to harvest from February to May - means 3 plants, of different varieties/person, you might consider growing 2 of the mid spring varieties. If you did that you would have 1m2/person, i.e. 4 plants and you will probably have a bit of a surplus for family in good years.
Purple sprouting broccoli, like all brassicas, can cope with a little shade, but it really responds well to full sun. It has a long growing period and a a big flower head to grow and then - hopefully - plentiful side shoots, that all takes a lot of energy. Most varieties do all of their flowering when light levels are low in winter and early spring., so give them light! Given it's long growing period and large it's not a good plant to grow in containers, consider calabrese instead.
Purple sprouting broccoli is a bi-annual, sown in summer and harvested the year later in winter and spring (depending on the variety)
There are a few varieties bred to grow as annuals, sown in spring and harvested in late summer/autumn, but I don't recommend them, the yield is often very poor by comparison and calabrese is at it's peak when grown during this period.
Almost all brassicas flower in spring, but purple sprouting broccoli is unique because it flowers to prolifically and beautifully. Once the large central head has been harvested, side shoots develop at the leaf junctions and these can be a good size and more than quadruple the harvest from the main head, the harvest can continue over a period of 1-3 months depending on variety.
PSB main head, with side shoots shown below
<aside> 💡 Winter flowering plants have a longer harvest period, but are less prolific than spring flowering.
</aside>
<aside> 💡 For more details on the model that I use for describing harvest periods (first earlies, second earlies etc) please see the chapter on my growing framework
</aside>
Purple sprouting broccoli is one of those crops that has very specific optimum sowing periods, but they vary by variety.
I particularly like the late spring/early summer sowings, because they provide much needed variety through winter and the hungry gap although they take up a lot of peak growing space. Autumn harvests - for me - are not worthwhile, because they take up space that is needed for my winter and spring crops, while providing only a small yield.
<aside> 💡 Note that because PSB has a fairly short peak harvest period, of only a few weeks, it's best to sow two successions in May and June, to stagger the harvest over two months. Purple Sprouting broccoli is unusual (a bit like carrots and potatoes) in that different varieties sowed at the same time have very different times to maturity.
</aside>