Crop type: Chicory
Cichorium intybus ‘Witloof Zoom’
Common name: Chicory ‘Witloof Zoom’
Crop slug: chicory
This Allotment Pro editorial draft summarises the cited RHS cultivar profile. Check the source and adjust cultivation decisions for local conditions.RHS cultivar profile
1 - Overview
‘Witloof Zoom’ is a forcing chicory that forms large, tightly packed chicons of white leaves when dormant roots are grown in darkness. The pale pointed heads are crisp and bitter-sweet, with yellow-green tips and a dense overlapping structure. They provide a distinctive winter and early-spring harvest when few outdoor salad crops are available.
Plants first grow outdoors to build substantial roots. Those roots are lifted in late autumn, stored cool and then potted in batches for forcing. Darkness excludes chlorophyll, keeping the new chicons pale, tender and less bitter.
2 - Size
- Ultimate height
- 0.1–0.5 metre
- Ultimate spread
- 0.1–0.5 metre
- Time to ultimate size
- 1–2 years
Forcing heads are harvested at approximately 15cm (6in) tall. About five prepared roots can be planted upright in a 25cm (10in) pot.
3 - Growing conditions
- Suitable soils
- Chalk, clay, loam and sand
- Moisture
- Well-drained or moist but well-drained
- Soil pH
- Acid, neutral or alkaline; ideally alkaline
Grow outdoor plants in soil that supports long straight roots without waterlogging. During forcing, use moist peat-free multi-purpose compost and avoid saturation, which encourages crown rot.
4 - Position and hardiness
- Light
- Full sun during outdoor root development; complete darkness while forcing
- Aspect
- East-, north-, south- or west-facing
- Exposure
- Exposed or sheltered
- Hardiness
- H6 — hardy throughout the UK and northern Europe, approximately -20°C to -15°C
The outdoor root crop is very hardy. For chicon production, move prepared roots into a dark space held at 10–15°C (50–59°F).
5 - Colour and seasonal interest
Forced chicons are ivory white to very pale yellow, with tightly overlapping pointed leaves and restrained yellow-green tips. This colour is a direct result of excluding light. Exposure after harvest turns leaves green and increases bitterness, so keep chicons covered and cool until used.
6 - Botanical details
- Family
- Asteraceae
- Native to Great Britain and Ireland
- No
- Foliage
- Semi-evergreen
- Habit
- Tufted
- Name status
- Unresolved
Genus
Cichorium includes annual and perennial plants with toothed or pinnately lobed leaves and loose branched stems bearing dandelion-like, usually blue flowers that close by early afternoon.
7 - How to grow
Cultivation
Grow the root crop in any moist but well-drained soil, ideally alkaline, in good light. Sow outdoors in May or June and thin plants to about 15cm (6in). Water during dry weather so roots develop strongly without bolting.
Lift plants in November and reject crowns less than 2.5cm (1in) across. Cut foliage to 2.5cm above the crown and store roots horizontally in sand in a cool shed. Plant selected roots upright in moist compost with crowns exposed, cover the pot completely and keep at 10–15°C. Harvest tightly packed heads when 15cm tall, usually after about four weeks. Re-covering the stump may produce a smaller second chicon.
Propagation
Propagate by seed.
Pruning
No routine pruning is required. Cutting back leaves at lifting is a crop-preparation step for forcing rather than ornamental pruning.
Pests
May be susceptible to slugs, snails and aphids. Inspect beneath forcing covers regularly because pests can remain hidden in darkness.
Diseases
Generally disease-free. Avoid excessively wet compost and remove any roots or chicons showing soft decay.