Radicchio is the red form of salad chicory. This salad vegetable is a form of chicory and like chicory can be forced for use as a winter salad, but the leaves can also be used fresh, without forcing. Young plants are green but when mature the plants are bright red with prominent white veins and a small well turned-in heart. It has become very popular as an addition to the winter salad bowl though too bitter, I think, to eat on its own. It can also be lightly cooked.
It can be tricky to grow especially in the colder parts of the country, as it is not frost hardy. Therefore in such areas grow it under protection, either glass cloches, cold frames or walk-in tunnels but not low plastic tunnels as they tend to hold too much dampness and this can lead to rotting of the heads.
The timing of sowing is also important as if sown too early the plants will bolt and if too late they will not be big enough to withstand the winter. Your best bet is to try sowing from early to mid-July and see which gives the best results in your garden.
Chose a warm position in the garden for this crop and one where the soil stays dry in winter. The area should be sheltered but not so sheltered that is stays damp and close and thus the crops grown there are more prone to disease. Since this is a salad crop it does not need a very rich soil, if the area was fertilised for a previous crop that should be enough but if in doubt give a light dressing before sowing.
There are very few varieties available, the only one in most shops being ‘Palla Rossa Bella', but try any other you can get. Sow as thinly as possible in rows 45 cms apart and when the seedlings are large enough to handle thin to 30 to 40 cms in the row. Alternatively you can sow a few seeds in bunches spaced at 30 to 40 cms along the row and then thin the bunches to one plant later.
Firm in the seeds with the back of the rake and if the weather remains dry, water the sown area lightly with a very fine rose on your can. Heavy watering using coarse drops will tend to cause a ‘panned' surface on any but the sandiest soils and this can interfere with the emergence of the seedlings.
After that all that is needed is to keep the crop free of weeds and watered in dry weather. As the autumn approaches if watering is needed, try to do it early in the day so as not to let the crop go into the night wet, as this can encourage rotting and disease.
Depending on the locality, it may be after Christmas before the plants have fully developed both their colour and shape. So the best advice is to leave the crop to grow until it has developed its full colour and is well hearted no matter how long it takes.