Gadenin日本語Get the appWhy they fall, and why it costs you
By late summer the stems stand six to ten feet (1.8 to 3 m) tall, carry a heavy head of rough leaves, and are anchored by a tuber sitting only four to six inches (10 to 15 cm) down. That is a large sail on a small foot. The first strong wind after heavy rain, when the soil is soft, lays a whole row flat in one night.
A flattened row does not simply look bad. The stems keep growing upward from wherever they landed, so they are impossible to stand back up, and the leaves end up shading each other instead of the sun. Since the tubers bulk up in exactly this late window, losing the foliage in early autumn means losing the last and largest share of the crop. Plants that go down in high summer often produce half of what a standing row does.
There is a second cost: a fallen row spreads sideways over whatever is next to it, and the buried stems can root where they touch damp ground, extending the colony into ground you had not intended to hand over.
The corral method, which is the one to use
Do not stake individual plants. There are too many of them, the stems are brittle where a tie bites in, and each plant sends up two or three stems anyway. Instead, fence the whole row: drive stout posts at the corners and every six feet (1.8 m) along, then run string or wire around the outside at two heights. The block of stems holds itself up, leaning on the string rather than hanging from it.
- Put the posts in early Drive them when the plants are around knee high, in early summer. Later than that and you cannot get to the middle of the row without breaking stems. Use posts at least eight feet (2.4 m) long, driven eighteen inches (45 cm) into the ground.
- Run the first line at waist height About three feet (90 cm) up, once the plants have passed that height. Run it around the outside of the whole row and pull it just tight enough to gather the stems slightly inward.
- Add the second line at shoulder height About five feet (1.5 m) up, added in mid summer. Two lines is enough for most sites. On an exposed plot, add a third at seven feet (2.1 m) before the autumn gales.
- Check the tension after every storm String stretches and posts work loose in wet soil. A two minute walk along the row after heavy weather, tapping posts back and taking up slack, is what actually keeps the row standing.
| Situation | Support needed | Line heights |
|---|---|---|
| Sheltered corner, single short row | Two lines on corner posts | 3 ft and 5 ft (90 cm, 1.5 m) |
| Open plot, exposed to wind | Posts every 6 ft (1.8 m), three lines | 3 ft, 5 ft, 7 ft (90 cm, 1.5 m, 2.1 m) |
| Along a fence or wall | Tie back to the fence at two heights | 3 ft and 5 ft (90 cm, 1.5 m) |
| Rich soil, very tall growth | Three lines plus shortening in summer | 3 ft, 5 ft, 7 ft (90 cm, 1.5 m, 2.1 m) |
Shortening the tops instead of staking them
If you would rather not put posts in at all, cut the stems back by about a third in mid summer, when they reach roughly five feet (1.5 m) and before flower buds form. They branch below the cut and end up as a denser, shorter, far more wind-stable block, and the yield penalty is small compared with the loss from a row that blows over.
The trade-off is that shortening removes leaf area at a moment when the plant is building it, so on a sheltered site where the row would have stood anyway you are giving something up for nothing. Cut only once. Repeated shortening through the season does reduce the crop noticeably, and cutting after flower buds appear costs more than it saves.
Shortening also reduces flowering. If you were growing the row partly as a windbreak or for the late yellow flowers, stake it instead of cutting it.
Keep a note of what went down
After any storm, record which end of the row leaned and which way. Sunchoke rows fail in the same place every year, because the failure is about the wind funnel on your particular plot, not about the plants. Two seasons of notes tell you exactly where the extra post belongs and whether the whole row would be better moved a few feet into shelter.
Note the date you put the posts in and the height the plants had reached. If you were too late to walk into the row, next year go in two weeks earlier.