While many plants that are favorites as mature crops can be safely grown as microgreens, I feel a few should be avoided, even though some seed vendors suggest otherwise. Here are eight:
Spinach. Spinach isn’t recommended as a microgreen because the seeds’ hulls cling tenaciously to the leaves. Since the hulls can’t be removed and are inedible, the microgreens are also inedible.
Buckwheat greens. When grown as microgreens and eaten raw, this crop contains dangerous toxins. People shouldn’t eat these microgreens, concluded Gilles Arbour, a member of the sprouting and raw-food community, who compiled the well-documented and compelling report, “Are Buckwheat Greens Toxic?,” which is available online. While on a health retreat in Florida, Arbour consumed large quantities of buckwheat greens by juicing them. He developed an itching and tingling rash on his suntanned body parts, and he noticed that others at the retreat did too.
Arbour learned that farmed animals, especially sheep, experience comparable symptoms when they forage on full-grown buckwheat plants. Through chemical analysis of buckwheat greens, he found that a pink-colored toxin called fagopyrin was the origin of his (and the animals’) malady.
Unlike the microgreen, raw buckwheat sprouts aren’t considered toxic, because soaking and repeated rinsing washes away the toxin, evidenced by the pink tint of the rinse water. Also called kasha, buckwheat groats that are toasted and then boiled aren’t implicated either, because cooking neutralizes the toxin.
Canola, chia, and collards. These simply do not taste good.
Celery, corn, and mint. These are very difficult to germinate, germinate very slowly, grow even more slowly, and offer very small yields.