Gadenin日本語Get the appKnowing when the root is ready
The rhizome does not fatten steadily through the summer. For most of the season the runner is a thin white cord traveling through the mud, and all the swelling happens in the last few weeks, once the plant stops making new leaves and pours everything it has downward. Dig too early and you will find a long stringy rope with nothing on it, having lost the whole crop for the year.
The signal is the foliage. When the standing leaves go yellow, then brown, and start to collapse at the end of the season after the first cool nights, the runner is done swelling. Give it another two to three weeks after the last leaf has browned, then dig. In a warm autumn the leaves may hang on a long time, which is good news: every extra warm week is thicker root.
You need a long hot season for this to work at all. Count on four to six months from planting to harvest with sustained warmth in the middle of it. A cool summer often produces a beautiful plant and a disappointing dig, and there is no fix for it at harvest time other than waiting as long as the weather allows.
One warning sign is worth acting on: if the water freezes solid in your area, harvest before that happens. Ice reaching down into the mud kills the rhizome and turns the segments to mush.
Digging the tub out
Harvesting a container is a wet, muddy job that takes about an hour and should be done in one go, in daylight, with the tub somewhere you can make a mess. Use your hands rather than a fork throughout. Segments are brittle and full of hollow chambers, and a fork will split them without you feeling it.
- Drain off the standing water Bail or siphon the water off until only wet mud is left, and cut away the dead leaf stems above the mud line. Working in clear mud instead of murky water is the whole difference between a clean harvest and a broken one.
- Start where the tip was pointing Feel down from the old planting position in the direction the runner set off, following the cord with your fingertips. The runner usually lies four to eight inches (10 to 20 cm) down and often circles the wall of the tub.
- Free the whole chain before lifting Trace the runner along its length and loosen the mud around it before you pull anything. Lifting a chain that is still anchored snaps the joints between segments, and a broken joint lets water into the chambers.
- Lift the chain flat, supported along its length Bring the whole thing up on two hands or a board rather than by one end. Rinse it in a bucket of clean water, not with a jet from a hose, which drives grit into the cut ends and bruises the skin.
- Set aside next year's planting piece Choose an undamaged section of two or three segments that still carries the pale growing tip at its end, and keep it whole. This is your seed for next spring and it must never dry out or lose that tip.
- Cut the rest at the waists Separate segments by cutting through the narrow joints between them, leaving an inch (2.5 cm) of the neck sealed on each end. Cutting into the body of a segment opens the chambers, and an opened segment discolors and spoils within a day or two.
What a good segment looks like
A well-grown segment is the size and shape of a fat forearm sausage, three to fifteen inches (8 to 38 cm) long and two to three inches (5 to 8 cm) across, with pale tan skin and firm ends. Cut across it and the chambers should be clean, round and evenly spaced.
Not everything in the tub is worth keeping. Sort as you go, because thin runner and damaged pieces will spoil the rest if they are stored together.
| What you dug up | What it means | What to do with it |
|---|---|---|
| Fat, firm, pale tan segments | The season was long and warm enough | Best eating. Store with the ends sealed |
| Thin cord with slight swellings | Not enough heat, or dug too early | Replant the tip and try again with more sun |
| Short, bent, knuckled segments | Runner hit the wall repeatedly | Usable, but move to a wider container next year |
| Gray or soft patches, sour smell | Rot from damage or a flooded stem | Discard. Do not use as a planting piece |
| Pieces with the growing tip intact | Next season's crop | Keep whole and wet until replanting |
Keeping it after the dig
Lotus root does not keep like a potato. The moment the skin dries the flesh goes gray and woody, and cut faces brown quickly on contact with air. Keep unwashed segments in a bag with a damp cloth in the cold part of the fridge and use them within a week or two, checking every few days for soft spots.
Next year's planting piece is stored differently again. It must stay cool, wet and dark until the water warms in spring: either leave it undisturbed in a corner of the tub with the mud kept wet and unfrozen, or keep it in a container of damp sand or water in a frost-free place where it will not dry out or start growing early.
Record what came out: the total weight, the length and thickness of the best segments, and the date you dug. Set that against the planting date and the midsummer leaf count from your notes and you will know, without guessing, whether next year needs a bigger tub, a hotter position or simply three more weeks in the ground.