Forcing/Blanching

Blanching is an ancient gardening technique which is surprisingly easy and effective. Pots, soil or even cardboard tubes are used to prevent light from reaching the young shoots of certain plants. This means that they rapidly stop producing chlorophyll. Over a few days or weeks this change in their chemistry means that they gradually become paler, not to mention more tender. They are also often triggered into growing quickly in an attempt to reach up towards the light. The stems and leaves tend to be milder and sweeter as a result, so this is a popular technique for bitter vegetables.

Checking on forced rhubarb in terracotta forcer - © Mark Winwood/GAP Photos

Checking on forced rhubarb in terracotta forcer – © Mark Winwood/GAP Photos

The first blanched rhubarb stems of the year are an eagerly-awaited treat. Covering established plants with a terracotta forcer brings on an early crop of extra-sweet and slender stems.

Apium graveolens 'Victoria' - Forcing Celery using newspaper - © Juliette Wade/GAP Photos

Apium graveolens ‘Victoria’ – Forcing Celery using newspaper – © Juliette Wade/GAP Photos

Forcing celery helps to create taller, milder stems which are delicious raw. Fold a sheet of newspaper into quarters and wrap it around the stems of each plant before tying with string.

Allium porrum - Young organic leeks with recycled toilet rolls placed around them to help with blanching - © Maxine Adcock/GAP Photos

Allium porrum – Young organic leeks with recycled toilet rolls placed around them to help with blanching – © Maxine Adcock/GAP Photos

The mild white stem of a leek is the most succulent part. You can blanch leeks by simply pushing a  toilet roll tube firmly into the soil over the stem of each young individual plant. Water well.

Row of Chicory forcing pots in vegetable garden - © J S Sira/GAP Photos

Row of Chicory forcing pots in vegetable garden – © J S Sira/GAP Photos

The distinctively spicy flavour of chicory can be too much for many palettes. Covering young plants with forcing pots gives the leaves a much milder flavour whether eaten raw or cooked.

Growing Cichorium - Forced Chicory 'Rossa di Treviso' illuminated by torchlight in the chicory forcing shed at Audley End - © Jonathan Buckley/GAP Photos

Growing Cichorium – Forced Chicory ‘Rossa di Treviso’ illuminated by torchlight in the chicory forcing shed at Audley End – © Jonathan Buckley/GAP Photos

If you want to force a large crop of a vegetable such as chicory, you can use a forcing shed to exclude light. The tender leaves can be harvested from early December through to February.