Graft Window: Fruit Tree Time

Grafting a fruit tree? Graft Window reads your forecast for a GO, WAIT, or DON'T today - by scion type, graft method, and the callus-forming window.

Should you graft today? Graft Window turns your local weather forecast into one clear answer - GO, WAIT, or DON'T - for grafting and budding fruit trees, based on your scion type, graft method, and the callus-forming window ahead.

Most grafts fail on timing, not on the knife. A graft only takes when the union forms callus, and callus needs the graft site to stay warm enough for about two weeks - while the nights don't drop too low and the midday sun doesn't cook the scion. A clear sunny day can heat the union far above the air temperature and dry the scion out before it takes. That is a moving, multi-part judgment that changes with every forecast update, and it is different for every scion, method, and yard.

HOW IT WORKS

1. Set up your plant: scion type, graft method (whip, cleft, bark, chip bud, T-bud, or patch), placement, and rootstock state.
2. Graft Window pulls the hourly forecast for your location and models the graft-union temperature and the callus-forming window ahead.
3. You get a single verdict - GO, WAIT, or DON'T - with the reason and the best hours to work today.

Under a minute to set up. No account required.

CORE FEATURES

Today's Verdict A single answer plus the why - workable hours today, union temperature range, and whether the coming days hold above the callus-forming floor. Built on published grafting temperature ranges and a solar-uplift estimate for the graft union.

Best Hours Today See the hours when the union stays in the favorable range, so you graft when the scion is least likely to dry out or overheat.

Method-Aware Guidance Chip bud, T-bud, whip, cleft, bark, and patch - each method has its own timing rules, so the verdict fits the graft you are actually making. Chip budding stays open when the bark is tight; T-budding needs the bark slipping.

PRO FEATURES Upgrade to Pro for deeper insights:

• Multiple saved plants, each with its own scion, method, and state
• 10 to 14 day callus-forming outlook so you can plan ahead
• Graft attempt log with take and fail tracking
• Personal calibration that learns your take rate per method
• Reminders for the next GO window and scion dry-out risk
• Multiple locations for home, cabin, or allotment

PRIVACY FIRST

• No account, no login
• All data stored locally on your device
• Location is used only to fetch your local weather forecast from Open-Meteo. Coordinates are never stored on any server.
• No tracking, no ads, no third-party analytics

Graft Window provides informational timing guidance based on published grafting temperature ranges and public weather data. Graft success also depends on technique, scion and rootstock condition, cambium alignment, and species compatibility. It is not a substitute for guidance from an experienced grafter or your local extension office.

Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/