Rosso di Chioggia

A round, red Palla Rossa (red ball) type, and the best-known chicory outside Italy. I have grown them for decades, with irregular hearting, except when using hybrid seed such as F1 Indigo.

Almost all the Palla Rossa varieties I grew were incredibly variable in the development of heads, with many forming small ones, if at all. The few larger heads then started to rot within ten days.

Then I discovered 506TT* and it was a revelation. Over the last three years I feel confident that every planting will succeed to about 90%, for decent sized heads which stand well.

*TT derives from the T&T seed company of Chioggia in the Veneto, NE Italy.

Rosso di Treviso Precoce

A Treviso which matures to a head in the garden before winter, without any need for forcing. For 33 years I barely succeeded with Treviso chicories when I grew the Franchi varieties, for example, a seed company that is family run and based in Italy. They supply the British company Seeds of Italy.

I felt so blessed to then discover 206TT. After 35 years of attempting to grow Treviso chicory, I was actually harvesting beautiful long heads of lovely flavour, with only a little bitterness. They are excellent in the salad mix because of their crunchy texture, and the leaves are not too big. For roasting, they are simply a treat.

Treviso Tardivo

This is more complicated because it involves forcing. Again, I struggled with the Franchi seeds because it is not clear on their packet that this is a forcing chicory. Their photo suggests to me that at least that you can grow lovely heads of Treviso in the field, late in the season.

I discovered on YouTube that they are harvested in late autumn and brought into sheds, where the roots sit on benches with running water around their lower part. New growth is in darkness, so there is a lovely blanched effect to the heads, after much peeling and trimming. To replicate this at home would be difficult!

Variegato di Castelfranco

Called the Tulip of Winter because of a beautiful leaf formation in its head, Castelfranco heads are slightly loose, helping them to be hardy to frost. The sowing date must be early enough to enable a large enough plant before winter, but not too early. Otherwise, the folded in leaves happen before winter. Later sown plants survive winter weather better, for welcome (though small) heads in cold and dark conditions.

The most dramatic aspect of Castelfranco is their leaf colour, because on the background of pale green there are dashes of vivid orange, yellow and pink. These become more intense towards the centre of any head, like a vivid sunset. They are a warming sight indeed in wintertime.

• Variegata da Lusia is a variety of Castelfranco, making tighter heads in autumn rather than early winter. Lusia’s heads mostly do not stand well, before rotting. But they are gorgeous to behold and mild to eat.

Rosso di Verona

With this type also, hearts do not form outside in the way shown on seed packets. Through many years of trying, the best result I had was rather insignificant and open heads. They had lovely quality and colour, but in too small an amount to justify the time and space needed.

Rose del Veneto

This is like a pink sister to Verona, with equally small harvests and intended for forcing. They are even more beautiful for being pink rather than dark red. I would say this and the Verona are not for amateur gardeners, unless you have a lot of spare time and space. In that case, they are fun to grow!

(Information on the above six types is helped by chicoryweek.com.)

Pan di Zucchero/Sugarloaf chicory

This has a drawback – it is very pale in colour. Leaves are perhaps a little papery in texture and less crisp than other radicchios.

Yet the folded-in central leaves are sweet indeed, a real treat in autumn and superb roasted as well. Sow and grow as for all radicchio – heads are large and can weigh over 1 kg/2.2 lb from sowing in late June.

Puntarelle (also known as Catalogna de Galatina)

A large plant that is grown for the young, hollow-stemmed flowering shoots, rather than leaves. The shoots develop into dense beautiful buds with many points, like thin broccoli. Upon harvest, they are separated and julienned into thin strips, then soaked in cold water for a few hours to remove some bitterness.

They develop an elegant curl and the texture is crisp – either eat raw or, more commonly, cooked. A delicacy of the Roman region, where it is highly esteemed.

‍

The propagation methods are similar to lettuce. The main difference is in timings.

• Seeds germinate in three to five days, reaching full two-leaf stage within a week.

Sowing conditions

Chicory seedlings germinate and grow in summer warmth. Under cover works well, with no worries about heat being excessive, unlike with lettuce. You can also sow in drills outside.

Sowing time

Timing requires precision, so I am giving the dates by month name rather than season.

First sowings here are in early June. If I sow even in late May, some of the plants bolt in August before making firm heads. If I sow after 26th July, plants grow fine but run out of time to make firm heads.

• Sowings from 8th–15th June give harvests in late August until early October.
• Sowings in late June to early July give harvests through autumn.
• Sowings in the second week of July give heads in late autumn to early winter, good for storage through winter.
• A small sowing as late as 20th–23rd July gives smaller heads in winter and even in January.
• Sowings for chicory to force are best from late May to mid-June.

Sowing method

Either sow in trays for pricking individual seedlings into module cells, or sow two seeds per cell and thin to the strongest. There should be no need for potting on, unless, say, you are waiting for a harvest to happen, such as onions, potatoes, beetroot etc.

Transplant size

Around 5 cm/2 in wide and high is good – this is often three weeks from sowing. Small transplants succeed best.

Transplant time and method

You are often transplanting into dry soil in summer, and after a preceding harvest that has taken a lot of moisture.

• You may need to water a bed before even making any holes.
• Dib deep holes as for any salad plant, a little deeper than the module.
• Push rootballs in firmly, and water them thoroughly.

Spacing

30 cm/12 in is the main spacing I use and recommend. You can space at 35 cm/14 in for larger heads and a slightly later harvest, also to grow larger roots for forcing.

How often

New plantings often need watering every day or second day until you can see strong new growth, the best indication that roots have established. If the weather continues dry and warm after that, water about twice a week until it rains and autumn arrives.

How much

Give a medium amount of water. Chicory plants are not huge but they grow fast, and head size is much influenced by moisture level, especially in the final third of their life. At the spacings I recommend, leaves will be touching each other and filling all the space within four weeks.

Extra mulch to retain moisture?

Do this in dry climates only, because slugs can breed quickly in the dampness under mulches such as straw. Chicory plants grow fast and do a fine job of mulching the surface with their leaves.

You don’t need to do a lot of this – mainly just at the stage when outer leaves are pushing against each other because all the ground is covered. This is within a month from transplanting. Do a second tidying after eight weeks or so from the transplant date, to keep slug numbers low.

Twist off several lower and outermost leaves. Many will be decaying and you may find yourself removing large slugs. Also, you may notice a few heads already developed.

How to judge the readiness of radicchio

About ten weeks after sowing, watch for leaves folding in around developing heads. They are less obvious than cabbage, for example, and it’s difficult to know how dense they are just by looking.

• Use your fingers to push into heads and feel if they are soft or firm.
• Best harvests are when they feel reasonably solid.
• If you wait more than two to three weeks after that, there is a risk of some decay on heads’ outer leaves.

How to pick

This depends on what you hope for after harvesting the head.

1. An option is to leave roots in the ground, for secondary harvests of much smaller heads. They are side shoots that grow out of the main stem.  Simply cut just below head level for your radicchio, and trim off outer leaves until you have a nice head. Next, at ground level, remove any decaying lower leaves, so that within one or two months you will see new but small shoots. They keep appearing until spring, depending on your climate.
2. When your aim is to clear the ground, harvest by grasping a plant with both hands, outer leaves and all. Gently rotate it, with a slight pull. This removes just the central cluster of larger roots and leaves most in the soil. Trim those roots and the outer leaves to find your radicchio.

Roots to force

Use a sharp spade pushed vertically down and close to the main root, then lever while pulling on the root’s shoulder. Do this in late autumn to early winter, before frosts colder than about –6 °C/21 °F.

Place the roots in pots or trays, with only enough compost that they stay moist. Use any tray and pack them in, at 15–20 cm/6–8 in apart – the closer spacing is for smaller roots.

Storing

Firm heads store well. Be sure there are no rotting leaves on the outside, and place them in boxes or crates to keep anywhere cool and damp. In my brick shed, with temperatures -1–10 °C/30–50 °F through winter, they store for up to six weeks.

Before eating them, you need to trim off a few decaying outer leaves. Slow growth continues in stored heads, with their central stem elongating as it moves towards flowering. So the number of usable leaves decreases all the time.

Saving seed

I have not tried this yet but I want to. I have not found information about how many plants you need for pollination to be successful. In 2020 I succeeded with just one plant of endive (a close relative of chicory), with subsequent growth through winter being strong and even.

This suggests there was no inbreeding from only one plant producing the seed, which is the case with lettuce. I think that chicory may be the same.

See more on Real Seeds UK website.

‍

‍

Which pests are likely, and when

• Slugs eat the tender leaves of new seedlings and the decaying leaves of older plants.
• Rabbits eat seedling leaves and any part of all plants.
• Deer chew out the central head of mature plants, your precious radicchio, and also chew the ends of outer leaves.

Protections needed

Bird netting is the best and easiest protection since you do not need to protect against insects. Use hoops to hold the netting above new plantings.

If the pests are deer, who graze larger plants, it’s sufficient simply to lay netting on top of all plants. Deer do not chew through it, in my experience.

Other likely difficulties

There are few. Bolting can be an issue, from sowing too early – wait until summer begins before you sow seeds.

‍

Clear

See ‘How to pick’ above. The main point is that any stem with its root system left in the soil will usually survive winter while growing more small chicory leaves, and then develop flower stems through spring. It’s fine to leave many small roots in the soil.