Calabrese
Tips for this summer-cropping brassica
CALABRESE, also known as Italian or green broccoli, is an anomaly in the large brassica family, preferring to develop its harvest in summer rather than winter. Early sowings should be ready now. But how do we get the best from it?
Successional success
This form of Brassica oleracea belongs to the same species that gives us our stalwart winter brassicas, yet it was developed in the Calabria region of Italy. While calabrese will grow through winter in an unheated greenhouse, most of us grow it as a summer crop.
The age-old issue of gluts is easily avoided if you sow small batches once a month from March until June; you can even store transplants in a fridge to plant out once a fortnight. Opting for earlymaturing varieties (like ‘Green Magic’) and late-maturing kinds (like ‘Spiridon’) helps stretch the harvest window further. Generous spacing will also encourage side-shoots to form; I’ve found ‘Ironman’ especially keen to side-shoot.
Care and cultivation
The secret to high yield is to help the plants to develop ample leaf surface area while young (this phase occurs before plants are stimulated to head up), and a strong root system. Avoid root congestion, and remember to water and feed regularly. Digging well-rotted
Sow under cover in modules during
March and April. Sow outdoors from May as direct sowings give best yields.
If you’re sowing in modules, plant out after five or six weeks to avoid root congestion, which can cause premature small heads.
Spacing the plants at 10x10in (25x25cm) will give main heads plus sideshoots later. This helps to spread the harvest and avoid gluts.
Keep the plants constantly well watered and feed regularly with a high-nitrogen liquid fertiliser or add chicken pellets on planting.
Cover over rows with butterfly netting (which also stops pigeons); if flea beetle, rootfly or aphids are local, use insect-proof mesh.
Harvest once the heads are sufficiently large but well before the individual buds show any signs of opening, then bag in the fridge. organic matter into light soils will help to prevent drying out, and will deter waterlogging on heavy soils.
If clubroot disease is a local problem, alleviate waterlogging this way, lime acid soils to pH 7 and grow varieties showing resistance (such as ‘Komodo’ and ‘Monclano’). Check plants regularly to harvest at the peak of perfection – and enjoy!