‘Hilling up’ all root vegetables

Robin Gale-Baker, from Sustainable Macleod discusses ‘hilling up’ your root vegetables. This is one of a series of articles she has written about growing various veggies (see right hand sidebar). She has also written a number of articles about growing various herbs, growing various fruit trees and general growing techniques.

‘Hilling’ or ‘hilling up’ of potatoes is a well-known technique for producing more tubers and preventing ‘greening’ (which is toxic to potatoes). Less well-known is that hilling up all root vegetables will lead to better produce. It will also prevent shoulder ‘greening’ of carrots.

Have you ever noticed the top of a carrot being green, particularly in situ in the row? This is caused by the carrot top growing above the soil, receiving direct sunlight and ‘greening’. The taste will be rather bitter (but it will not be toxic as potatoes are when they are exposed to sunlight). Obviously, you can simply cut the top off and use the rest of the carrot but an even better option is hilling it up instead – and then you can eat the whole carrot.

Hilling can be done in one of two ways.

1. The first way is to create a hill or mound by hoeing the soil and pulling it up into a long, raised row. Seeds or seedlings are then planted directly into the top of the mound.
2. The second way is to sow root vegetables in a ‘flat’ bed (i.e. a normal in-ground bed) and, once shoots emerge, soil is scraped from both sides and hilled up to cover the shoulder of the plant. The shoots should not be covered but any protruding shoulders of the veggies should.

Hilling has a number of general advantages including:

• Providing good drainage.
• Keeping weeds at bay.
• Fluffing up soil, allowing roots to penetrate deeper and swell more easily so they take up more nutrients and water.
• Protecting tender shoots from bad weather and supporting the plant’s stability in the soil.

Root vegetables are meant to fully develop underground but you may notice that they can sometimes protrude 3-4cm above the soil. This may be the result of seed that germinated just beneath (or on) the surface of the soil, or a lack of water. Protruding tops never taste good, they lack juice and have a tendency toward woodiness.

It pays to keep an eye on all root crops and, around a month after germination, check that the shoulders of your carrots, parsnips, turnips, beetroot, etc are covered. If not, or perhaps anyway, use a trowel to break up the soil either side of the rows and drag it into a mound over the tops leaving the new shoots exposed.

Then repeat your inspection every 3 or 4 weeks and hill when necessary.