Gadenin日本語Get the appDivision is the method to use
Sorrel is a clump-forming perennial with a fleshy taproot and a crown that widens each year, which makes it straightforward to divide. Division gives you plants identical to the parent, in crop within weeks rather than months, and it simultaneously fixes the woody-center problem that reduces an old clump's output. There is very little reason to raise replacement plants from seed once you have one good clump.
The right time is early spring, just as the first leaves show and before the plant is in full growth, or early autumn once the summer heat has gone and there are still six weeks of root-growing weather ahead. Avoid dividing in the middle of summer: the cut roots cannot supply the leaves, and the pieces sit and sulk or die outright.
- Lift the whole clump Push a fork in about 8 inches (20 cm) out from the crown all the way round and lever the clump up whole. Sorrel roots go deep, so dig deeper than feels necessary; a snapped taproot is slow to recover.
- Wash or shake the soil off You need to see where the buds are. Shake off loose soil, or rinse the crown with a hose, until the growing points on top of the crown are visible.
- Discard the woody middle On a clump three years old or more the center is hard, dark and unproductive. Cut it out and compost it. All the useful growth is in the outer ring.
- Cut into pieces with a bud each Use a knife rather than tearing. Each piece needs at least one visible growing point and a decent length of root. Pieces the size of a golf ball are ample; smaller ones survive but take a season to catch up.
- Replant at the same depth Set each piece so the crown sits level with the soil surface, 12 to 18 inches (30 to 45 cm) apart. Buried crowns rot, proud crowns dry out.
- Water in and shade briefly Water thoroughly to settle soil around the roots. If the weather is bright, shade the divisions for three or four days. Do not pick anything for six weeks.
One healthy three-year-old clump gives four to six good divisions. That is normally more sorrel than a household needs, so plan where they are going before you lift the parent.
Raising sorrel from seed
Seed is how you start from nothing, and it is easy. Sorrel seed germinates readily in cool soil, in seven to fourteen days at 45 to 70F (7 to 21C), sown a quarter of an inch (5 to 8 mm) deep. Sow in early spring or late summer, thin ruthlessly to 12 to 18 inches (30 to 45 cm), and expect a light picking in the first season and a full one in the second.
The one drawback is variability. Seed-raised plants differ from one another in leaf size, vigor and, most noticeably, how early they run to flower. In any row of ten you will have a couple that bolt a fortnight before the rest. Grow them all on for a season, mark the best two, and use those as the parents for future divisions. That is how you end up with a strain that suits your own garden.
| Method | Time to a full crop | Plants are | Best used when |
|---|---|---|---|
| Division of an established crown | One season | Identical to the parent | You already have a good plant |
| Sowing seed in spring | Two seasons | Variable | Starting from nothing, or wanting many plants |
| Sowing seed in late summer | The following spring | Variable | Filling a bed cleared of a summer crop |
| Transplanting self-sown seedlings | One to two seasons | Variable | You have seedlings anyway and want them somewhere useful |
Self-seeding: free plants, or a weed problem
Sorrel self-seeds very heavily. A single plant allowed to flower and ripen produces thousands of seeds that drop straight down and germinate in a dense mat around the parent, in the paths, and anywhere the wind or your boots carry them. Within two seasons of ignoring one flowering plant you will be weeding sorrel seedlings out of beds several feet away.
Decide deliberately which side of this you want to be on. If you want free plants, let one plant flower, watch the seed heads turn from green to rusty brown, and cut the whole stem into a paper bag before it shatters. That gives you controlled seed you can sow where you choose. If you do not want the plants, cut every flower stem at the crown as it appears and the problem never starts.
Self-sown seedlings that do appear are easy to deal with while they are small. Hoe them off at the cotyledon stage or pull them at two leaves, when the root is still short. Left until they have made a taproot, they snap when you pull and regrow from the piece left behind, and then they are genuinely tedious to remove.
Growing sorrel in a large container is the simplest way to have the plant without the seedlings. Any seed that drops stays in the pot, where you can see it and scrape it off.
Keep a record of which plant came from where
Because seed-raised sorrel varies and division does not, it pays to know the parentage of every clump you have. Note which plants came from seed, which came from division, and which parent each division came from. A simple sketch of the bed with dates on it is enough.
Add one line each spring about which plants bolted first and which stayed in leaf longest. After two seasons that record identifies your best plant with no ambiguity, and every division you take from then on is an improvement rather than a lottery.