Gadenin日本語Get the appThe peg is the whole story
Peanut flowers are small, yellow and pea-shaped, and they appear in the leaf axils low down on the plant about six to eight weeks after sowing. They pollinate themselves, usually before they fully open, and then they wither within a day. Nothing swells at the flower. Instead the base of the fertilized flower elongates into a stiff, pointed stalk called a peg, which turns downward, grows an inch or two, and drives its tip into the soil. Only once that tip is two to three inches (5 to 8 cm) underground does it turn sideways and begin to swell into a pod.
This single piece of behavior dictates everything about how the plant is managed. The pods are not on the roots; they are on the ends of stalks that had to travel from a flower down through the air and into the ground. Anything that stops a peg reaching soft soil, or that snaps it after it arrives, costs you a pod. A peg that meets hard crust, a sheet of mulch, a stone or a bootprint simply stops growing and dies, and the flower that produced it is wasted.
Pegs appear roughly two weeks after the first flowers and continue for six to eight weeks. A single healthy plant produces well over a hundred flowers and typically converts thirty to fifty of them into filled pods.
Keep the ground open: no mulch, no treading, no deep hoeing
From the first flower onward, treat the eighteen inches (45 cm) of ground around each plant as a surface that must stay soft and clear. Do not mulch it with straw, bark, cardboard or plastic sheet. Mulch is normally good advice for a summer vegetable, and it is the wrong advice here: a peg cannot push through matted straw or a plastic film, and the pods that would have formed under that mulch never exist. If you need something on the surface to hold moisture, use a half inch of sifted sand or fine compost that a peg can penetrate.
Stop hoeing once pegs are down. Weeds pulled by hand after pegging tear the pegs of the plant beside them, and a hoe blade cuts them off wholesale. The rule most growers settle on is simple: cultivate freely until the first flower, weed carefully by hand between first flower and first peg, and after that leave the ground alone and tolerate the weeds that remain. Lay a board across the bed if you must reach the far side, and never stand on the pegging zone; compacted soil is as effective a barrier as a paving slab.
| Stage | What is allowed | What it costs to get wrong |
|---|---|---|
| Emergence to first flower | Hoe, weed, hill, cultivate freely | Nothing. This is the window for all soil work |
| First flower to first peg | Hand weeding only, shallow and gentle | Broken pegs before they even reach the soil |
| Pegging and pod fill | Water and foliar checks only | Every disturbed peg is one lost pod |
| Last three weeks before lifting | Nothing at all, and reduce watering | Sprouted or split pods, and difficult curing |
Water: steady through pod fill, dry at the end
Peanut is drought-tolerant enough to survive a dry spell but not to yield through one. The critical period runs from the first flowers to about three weeks before harvest, roughly sixty days in the middle of the crop, and during it the plant wants around an inch (25 mm) of water a week including rain. Dry soil in this window has a second effect beyond simple stress: a hard, dry crust physically prevents pegs from entering, so the plant flowers into thin air and sets almost nothing even though it looks healthy.
Water in the morning at the base of the plant rather than over the top, because leaves that stay wet into the night are how leaf spot gets established. Then, in the last two to three weeks before you intend to lift, cut watering right back. Pods that finish in wet soil are difficult to clean, cure badly, and in warm ground can germinate inside the shell. A firm, drying-down finish is what makes the difference between nuts that store for a year and nuts that go moldy in a month.
- Check moisture at peg depth Push a finger three inches (8 cm) into the ground beside the plant. If it is dry at that depth during flowering, water deeply the same day.
- Soften a crusted surface before it sets If the surface has baked hard after rain, break it very gently with your fingertips before pegs are down, never after.
- Taper off before harvest Stop irrigating two to three weeks before your planned lifting date so the soil is dry enough to shake off the pods cleanly.
Feeding: calcium at flowering, and almost nothing else
The pods absorb calcium directly from the soil around them, not through the roots and stems, so calcium has to be present in the top three inches (8 cm) exactly where the pegs are working. Without it you get what growers call pops: pods that look normal from the outside and are empty or half-filled when you crack them. Work a dressing of gypsum, which supplies calcium without shifting pH, into the surface soil around the plants as the first flowers open. A generous handful per plant, watered in, is the usual rate, and it matters most for the large-seeded types.
Beyond that, feed very little. A nodulated peanut supplies its own nitrogen and a nitrogen feed produces leaf at the expense of pods. Potassium is worth having in the bed at sowing but should not be broadcast over the pegging zone late in the season, because high potassium at the pod competes with calcium uptake. Yellowing between the veins of young leaves in midsummer usually means manganese or iron shortage from a pH that has drifted too high, and is fixed with a foliar feed rather than more fertilizer in the soil.
Record the date of the first open flower. Everything else in the peanut year is counted from it: pegging about two weeks later, the calcium dressing at the same time, and the earliest sensible test dig roughly ninety days after.