Gadenin日本語Get the appA long season with four decisions in it
Taro asks for patience more than skill. Between planting and harvest lie six or seven months in which the plant does one thing steadily, and there are only four moments where your decisions materially change the result: the date you plant into warm soil, whether the ground stays wet through midsummer, whether you hill, and when you dig. Everything else is maintenance.
The crop is also unforgiving about the total length of that run. Below 150 days from planting you get small corms whatever you do, and a full-sized main corm generally wants 180 to 210. Before anything else, count the frost-free days in your garden. If the number is tight, the answer is not to rush the planting date into cold soil, which achieves nothing, but to start the corms in pots indoors six weeks ahead and set them out already growing.
| Turning point | When | What it decides |
|---|---|---|
| Planting into warm soil | Soil above 65F (18C) | Whether the corm sprouts or rots |
| Water through midsummer | Full canopy onward | Final size of the main corm |
| Hilling rounds | Three leaves, then six weeks later | Number and size of side corms |
| Digging date | Before first frost, after 180 days | Total yield and how long it stores |
The season stage by stage
The stages below are written relative to your last spring frost and your first autumn frost rather than to calendar months, so they read the same in either hemisphere. Work backwards from the first frost date to check the crop fits before you order corms; there is no point discovering in late summer that you were forty days short.
In a frost-free climate the schedule is simpler still, because you are governed only by the 180 to 210 day run and by the wet season, and corms can be left in the ground and dug as needed. In a temperate garden, frost is the hard stop and the whole calendar is arranged around getting the maximum warm growing time before it.
| Stage | Main jobs | The point of it |
|---|---|---|
| Six weeks before last frost | Pot up seed corms indoors if the season is short | Buys six weeks of growth without cold soil |
| Two weeks before last frost | Dig in compost or rotted manure, open the planting trench | Feed and water-holding for a long hungry season |
| Two to four weeks after last frost | Plant corms 4 in (10 cm) deep, 2 ft (60 cm) apart, once soil is above 65F (18C) | Warm soil is the trigger, not the calendar |
| Planting to emergence | Keep the trench damp, hand weed | The corm has no roots yet and cannot fetch water |
| Three to four leaves | First hilling, 3 in (8 cm). Start regular feeding | Fills the trench and covers the crown |
| Midsummer, full canopy | 2 to 3 in (50 to 75 mm) of water a week, mulch, second hilling | Corm bulking; this is where the crop is made |
| Late summer | Third light hilling where corms show, watch for leaf blight | Prevents greening and keeps the canopy working |
| Two to three weeks before digging | Stop watering | Firms the skins so corms cure and store |
| Before first frost, after 180 days | Cut the tops, lever the clumps out, cure a week | Frosted foliage passes rot down into the corm |
Early season: warmth and water, nothing else
From planting to the third leaf is roughly six weeks, and it is the part of the season where most crops are lost. Two things do the damage: cold soil, which stalls the corm and lets rot in, and a dry spell during the two to four weeks before emergence, when there is no root system to fetch moisture from any depth. Keep the trench damp and be patient. Uneven emergence over three or four weeks is normal and gaps often fill later.
Weeding is the other early job. Young taro competes badly, and the canopy that will later shade out everything is not there yet. Hand weed within a foot of each planting position weekly until the leaves meet across the row. Do not hoe deeply; the roots run wide and shallow and are easy to cut.
- Plant on a soil thermometer, not a date Wait for 65F (18C) at four inches (10 cm). Two weeks of patience beats a fortnight of a corm sitting in cold ground.
- Never let the row dry before emergence Check every second day in warm weather. A dry spell now kills the sprout underground with no warning above.
- Hand weed weekly for six weeks Shallow work close in, never a deep hoe. Once the canopy closes, weeds stop being a problem for the rest of the season.
- Feed once growth starts Begin a balanced feed at the three-leaf stage. Taro is a heavy feeder over a long season and pale small leaves mean a small corm.
Midsummer: the weeks that make the crop
Once the canopy is full, the plant is bulking the corm and everything depends on water. Two to three inches (50 to 75 mm) a week is the target, delivered at the base rather than over the leaves, and a single week of drought here costs more than any other mistake in the season. Mulch four inches (10 cm) deep over warm soil to halve the evaporation and keep the shallow roots cool.
The second hilling falls in this period, four to six weeks after the first, and it is what turns a handful of tiny side corms into a real share of the harvest. Draw three to four inches (8 to 10 cm) of soil in from the path, keeping it clear of the leaf stalks themselves. This is also the season for leaf blight in warm wet weather: cut out and remove infected leaves promptly rather than leaving them to shed spores over the row.
- Water to two or three inches a week At the base of the plant, evenings in hot weather. Rain that lands on the canopy largely runs off and does not count.
- Hill a second time Three to four inches (8 to 10 cm) of soil drawn in from the path, four to six weeks after the first round. This is where side corms come from.
- Mulch after the soil is warm Four inches (10 cm) of straw or shredded leaves, pulled back two inches (5 cm) from the stalks. It roughly halves your watering.
- Remove blighted leaves on sight Cut whole affected stalks at the base and carry them off the plot. In warm wet weather blight can strip a canopy in three weeks.
End of season, and the record that makes next year easier
The wind-down starts when new leaves arrive smaller and the plant stops replacing what it sheds. From that point count two to three weeks, stop watering, and prepare to dig. In a frost climate the frost date overrides everything: cut the tops off and dig immediately if frost is forecast, because frosted foliage carries decay down into the corm within a day or two. Cure the corms for about a week in a warm shaded airy place, then store them cool at 50 to 55F (10 to 13C).
Then write the season down, because at this length no one remembers it accurately. Note the planting date and the soil temperature, the emergence dates, both hilling dates, when leaf blight first showed and what the weather was, the date you stopped watering, the harvest date and the total days, and the weight of main corms and side corms separately. Two seasons of that turns taro from a crop you hope goes well into one you can schedule, and it is the only way to find out whether your own garden can carry it the full 200 days.
- Count from the last full-sized leaf When new leaves arrive noticeably smaller, the corm is finishing. Stop watering two to three weeks after that and plan the dig.
- Let frost set the deadline Dig before the first frost regardless of stage. If frost catches you out, cut the foliage off and dig within a day.
- Cure a week, then store cool Warm, shaded and airy for about a week, then 50 to 55F (10 to 13C) in open crates. Do not refrigerate and do not seal in bags.
- Save your best side corms for seed Set aside firm medium-sized side corms, store them with the crop but marked separately, and note how they perform next season.
- Write the whole season down Dates, temperatures, hilling rounds, blight, and separate weights for main and side corms. It is the only record long enough to be useful.