Radish

Raphanus sativus

Radishes are quick-growing, peppery roots in the mustard family. The roots and greens are edible, and varieties range from mild breakfast radishes to dense winter storage radishes.¹

The swollen part called a root is mostly a thickened hypocotyl and upper taproot, a storage organ that can be round, tapered, or long like a daikon. The leaves remain useful food as well, and the plant can also be harvested young for its cotyledons and first true leaves as a microgreen.²

That bite is generated only after tissue is damaged, when an enzyme produces a volatile mustard oil. Much of the enzyme is concentrated in the skin, so peeling moderates the pepperiness. Cooking inactivates the enzyme, reducing pungency and revealing more sweetness.³

Radish can be sown very early and again later in Maine, so it works as a short-cycle crop at either end of the garden year. Cool conditions and steady moisture help the roots stay crisp; drought or slow growth tends to make them woody or excessively hot. Garden radishes may be ready in three to five weeks, while larger daikons take longer and can be stored for a limited period after harvest.⁴

The familiar mustardy bite comes from glucosinolate defense chemistry. Cutting or chewing breaks plant cells and lets enzymes convert those compounds into volatile mustard oils; the resulting aroma is part of why a radish tastes sharper freshly sliced than whole. Heat softens that pungency by disabling the enzyme, while the raw root keeps its crispness and peppery lift.³