Cultivation of thistles

How to grow thistles (cynara cardunculus)

Photo of thistle or cardoon (Cynara cardunculus)

Description of the plant and varieties

Perennial plant of the daisy family of up to 1.5 m in height. Stems erect, stout with stripes which arise from a basal rosette of gray leaves up to 1 m long, very divided, with yellow spines finishing off the ends of the lobes, so the difference mainly from Cynara scolymus (artichoke) that does thorns on the leaves and these are not so divided. Flowers very large chapters of up to 5 cm in diameter, purplish blue, rarely white. The fruit is achene.

Its origin is in the Mediterranean where it grows naturally on banks, roadsides, rocky and arid and sunny. Widely grown in this area for its leaf stalks, is especially popular in Spain, Italy and France. Has also been adapted in some parts of America such as Argentina and South America where the resistance of this plant and the fact that these areas have climates suitable for the development has become an invasive thistle.

There are varieties specially grown for its flowers and its ease of cultivation as garden plants.

Among the many varieties we can emphazise these ones:

– White thistle: nearly thornless stems presents a height less than most varieties, reaching just over one meter. Variety of whitish color and texture extremely strong. Highly prized in cooking.

– Ingegnoli giant: Very resistant and very tender Italian variety without thorns.

– “Violetto di Chioggia”: Italian variety used in particular by its purple flowers and ornamental plants in flower beds.

– “Grosso Romanesco”: One of the most delicious Italian varieties for cooking.

– “Green Globe”: Another gardening variety suited for mild climates.

– Varieties from Navarra: Spanish area with a long tradition in the production of thistles. Among the many varieties we can highlight: Green Tafalla, Blanco de Peralta, Peralta Green, Red or Full Corella of Spain.

– Benicarló thistle: Spanish variety where the artichoke thistle and have a tenderness and a very high storage capacity because it does not become so black as most varieties when cut.

– Thistle Burgo de Osma or full white: Thistle from the town of Burgo de Osma, in the province of Soria (Spain) is characterized by its gray-brown color and softness.

– French Varieties: Among the many varieties include the thorny thistle Tours or green chard Vaulx-en-Velin

Irrigation of the thistles

The thistle or cardoon, although it is a wild plant that can really hold the dryness, you need water to produce soft stems and vigorous. Can be planted in dry locations, although production decreases and the quality of thorns for the market is smaller.

It is essential that the ground is well wet when planting takes place. It should also maintain constant humidity in the summer, so you have to water regularly especially in hot, dry summers. Watering should be regular, but should avoid stagnation.

Environment and exposure of the thistles

It requires a sunny exhibition or of semishade. It prefers a temperate climate although there are varieties more resistant than they can adapt in climates fresher than they are those that, in fact, produce less bitter plants. (In very warm climates they can be too bitter). Outside the Mediterranean regions it grows well in free places of frost that are near the coast and which they present/display fresh summers.

The thistle is sensible to the frosts, especially when the plant is young and it is not established well, reason why, in colder climates he is advisable to propagate it in covered seed plot. Once it has grown, which ground to happen in the second year, can hold temperatures below 0º C although the plant is affected.

Propagation of the thistles

May be reproduced by planting seeds in winter (February-March) to be growing in or directly on the ground in spring. (April-May)

The first case is suitable for cooler places, exposed to early frosts of autumn. Seedlings should be planted in a protected during the months of February and March. The transplant is usually performed on half of May or October.

In milder climates, devoid of spring and autumn frosts, can be planted directly in the field. In this case, would be used about 5 seeds per hole at 1 or 2 cm deep at a distance of 80 cm between plants and 100 cm between rows and row. When the seedlings have developed 7 or 8 leaflets, we will only one for each hole, eliminating the others.

While cardoons can be played by planting seedlings, is not very advisable to use this technique because the young plants which produce edible heads and stalks not very hard.

Types of land and fertilizer of the thistles

Thistles are very resistant plants that can grow into any type of terrain. However, they prefer deep soil rich in humus, that can withstand moisture well but at the same time, they have good drainage and are not waterlogged.

It is important to work the ground before planting. We remove dirt and get a loose soil with a minimum depth of 40 cm that are necessary to sink the roots evenly and produce quality plants. After removing the soil, add manure at a rate of 8 kg/m2 and stir the mixture. It may be interesting to add some potassium or phosphorus.

Care and harvesting of the thistles

To produce quality thistles is necessary, besides weeding (weeding), perform other tasks that make the thistle in a valid product to eat. The main task is to whitewash the stems of the leaves so the leaves are more tender and appetizing. This is done with the technique of ridging which is to protect the plants from the sun to not give them the light and turn white. This can be done by different methods as:

– In early autumn, and for a month or so, will be attached leaves and its entire surface except the ends with some material (straw, paper, etc.)..

– In early autumn, for about 20 days must be attached leaves and cover the whole surface of the plant less in the ends of the earth.

– Once the stems have been cut in late autumn or early winter on earth are buried the stems and covered with straw over a month.

The collection of cardoons can be done from late summer from September to the varieties planted earlier and throughout the fall and winter. Bleached leaves should be cut leaving only the central portion thereof corresponding to about bunches of about 40 or 50 cm in length and about 5 cm wide.

Pests and diseases of the thistles

They are the same that affect the artichoke.(See details)

More information on the properties of thistles

Written by Editorial Botanical-online team in charge of content writing

8 April, 2022