Root Harvesting
by Sara Katz

The herbal farming season is defined by the parts of the plant which are harvested. In spring we harvest the new, succulent herbage; in summer the flowers; late summer produces seed; and finally, fall is root harvesting season.

Root harvest is always interesting, as, unlike the harvest of the upper portions of a plant, the root cannot be seen until it is out of the ground. Root digging is like hunting for buried treasure, and, to add to the excitement, there is only a small window of time in which to get them out of the ground. On the Pharm Farm, we wait until a hard frost has killed back or yellowed the top of an herb before uprooting it. This is because then the plants "energy", it’s greatest concentration of nutrients and other constituents, is underground in the roots. This is the time roots are best harvested and their essence captured. In most areas, fall frost also means the coming of rain or snow, so the rush is on to dig the roots before the ground is too wet to run machinery or hand dig without damaging the soil structure. There is also an urgency to plant a cover crop into the harvested ground in order to protect and build the soil.

Roots come in as many shapes and sizes as the upper parts of the plants. Some are fibrous and mop-like, like Valerian, and some are tap roots, like Dandelion. Some roots run along the surface while others dive deeply into the soil. Our Gravel Root was so big this year that we had to use tractor orklifts to get them out of the ground. To a farmer, this plant gets it's name, not from it's action on the human body, but for it's habit of holding gravel in it's massive fibrous root system. Plant Gravel Root in the full sun where it gets lots of water and you will be rewarded by a giant plant up to 10 feet high with large purple flower clusters.

Stone Root, on the other hand, has small, dense roots which resemble stones and, when dried, is so hard it will damage grinding equipment. You probably know that Goldenseal is golden on the inside, and Bloodroot is red. Black Cohosh has blackish roots; Pleurisy root is brittle; Culver's root is tough; Astragalus grows deep; and Nettle root is like underground rope. Each root requires a different process to dig, wash, and, if necessary, dry.

Root harvest almost always requires a large amount of soil disturbance, especially when using machinery to harvest on a large scale. It is wise to get a cover crop on the ground right after harvest, so as not to leave the soil bare to the winter rains. After the latest harvests, we will either spread straw over the ground to protect it, or plant a late germinating cover crop like annual ryegrass.

Many times a root harvest will provide material to replant. Most roots will divide easily and provide small roots which can be replanted to replace the mother plant without having to wait for seed to germinate and grow. For the home grower, this can be the solution to digging up one of your favorite perennials to make medicine; and even for a farmer it can cut years off of the turnaround time until the next harvest.

After roots have been dug, the farm and garden can be put to bed for the winter – perhaps the biggest reward of all!