Daikon radish, also called Giant Japanese Daikon radish is a member of the Brassica family. Its botanical name is Raphanus sativus var. Longipinnatus. It is sown as an annual cover crop in vineyards, particularly in parts of California.

As a cover crop: Daikon radish has a number of positive attributes, according to Dave Koball, who says ‘Daikon radish flowers well with mustard, flowering just as the mustard flowers are fading. After disking, which cuts off the head of the radishes, and once the Daikon radish tap root dies in the soil, it decomposes to leave a roughly 2.5cm (1 inch) by 15 cm (6 inch) hole in the grown which is good for water penetration. The long tap root helps aerate the soil, too, and is a good source for organic material, reducing demineralization or leeching, mainly of potassium and nitrogen. The radish roots attract nematodes but then produce mustard oil in the soil to kill the nematodes, contributing to a form of biological fumigation.’

Requirements: Daikon radish needs loose soil to be able to do its job of ‘bio-drilling’, building a vertical taproot rather than merely a shallow ball-like stub. It will rot in wet soils or areas with standing water.

Sowing: Daikon seeds are very small.