Rosetare

Rotations break because nobody remembers three months back

Resistance builds against a mode-of-action group, not against a product name. Two products with different names and different labels can sit in the same group, and one tank mix can put several groups on the plant in a single pass.

The principle is well known. The hard part is remembering what you used in April when you are standing in the garden in July. Rosetare records the group with every spray and tells you when the same one comes round again.

You enter the group code from your own label

Rosetare holds no lookup table from active ingredient to group code, and no product names at all. When you add a product to your library, you type in the group code printed on the label in front of you — 3, M5, 4A.

In exchange, any product in any country works the same way. The app says so on screen, permanently: active ingredients and mode-of-action group codes are the ones you entered from your own product label. That note cannot be switched off in settings.

A mode-of-action group also does not mean the product is approved for use where you live. Always follow the product label and the pesticide rules that apply in your area.

The check reports a fact, not a verdict

When a group comes round again, Rosetare shows you how many sprays back it appeared, and which group it was. It does not call it good, bad or a mistake. Whether it matters depends on the products and on the pest or pathogen.

For the same reason, Rosetare refuses to fold "cannot tell" into "no overlap". This is the first record in the zone / the earlier sprays have no code entered / this spray has no code entered — each of the three gets its own wording, and none of them says "no overlap found".

See the groups you have been using as a band of colour

Each zone's spray history is drawn as a timeline of colour segments. A spray containing several groups splits into several segments, and an amber rule marks the boundary where the same group runs on into the next spray.

Colour is never the only carrier. Every segment also prints its group code, because there are more groups than there are distinguishable colours. Warnings are never red — on a screen about plant disease, red reads as "lesion", so amber carries the caution and red is reserved for confirming a permanent delete.

Five diseases, reported separately

Rosetare shows whether the conditions that make infection likely have been present for black spot, powdery mildew, downy mildew, rust and grey mould. There is no combined risk score. The five need genuinely different conditions, and averaging them would destroy the information.

Each card has three states — conditions met / conditions not met / not enough data to judge. Missing data is never shown as "not met"; instead the card tells you how many more days of weather history it needs.

Every card opens onto the conditions it is testing — hours of continuous leaf wetness, temperature band, relative humidity — and the source those figures come from.

Leaf wetness is an estimate, and the app says so

The centre of every infection condition is how many hours the leaf stayed wet, and no ordinary weather feed measures that. Rosetare estimates it from temperature and relative humidity, using a humidity threshold that varies with your climate zone.

The error is roughly ±1.5 to 2 hours. That note sits permanently on the risk screen and cannot be hidden. If the threshold does not match your own garden you can shift it by up to ±5% in settings. Each plant records where it grows — open ground, a container, under eaves, or indoors — and when every plant in the garden is sheltered from rain, rainfall is not counted towards wetness.

Where the evidence is thin, it is labelled thin

Black spot has no published, field-validated forecasting model. Rosetare shows the infection conditions that university extension sources agree on — continuous leaf wetness by temperature band, plus relative humidity of 95% or more as a separate route — and does not call that a validated forecast.

The powdery mildew score adapts an approach published for a related pathogen group (grape powdery mildew, the UC IPM Gubler-Thomas Risk Index). It has not been validated for the fungus on roses. That one card is deliberately formatted differently from the other four so you can see at a glance that it is borrowed.

If you choose "not sure / other" for your climate, the humidity threshold used is interpolated between published values. The screen says that the interpolated figure is not itself backed by a source.

Three ways to set your place. Location sharing is optional

Weather is fetched for a latitude and longitude. You can set that from your current location, a place-name search, or coordinates you type in — and the last two on their own drive every feature, Premium included.

Rosetare does not ask for location permission during onboarding. It asks only if you tap "use my current location", and if you decline it simply offers the place search instead.

Sprays are recorded against a zone, not a plant

Resistance builds in the population of pathogens and pests living in a place, not inside one bush. So a spray belongs to a zone. Gardens hold zones, zones hold plants, and each plant records its exposure.

The moment you save a spray, the group codes it carries are written down as a snapshot. Editing the product in your library afterwards never rewrites a past check.

Deleting a zone happens in two layers. Archiving takes it out of the lists and out of the rotation check, but every spray record is kept — they still appear in the spray history and the CSV export, and restoring the zone resumes the check where it left off. Permanent deletion counts the spray records that will go with it and shows you that number before it asks.

After the latent period, it asks what you actually saw

Once the latent period for a disease has passed, Rosetare asks you once: around this date the conditions for this disease were met — did you see it? Yes or no, either is fine.

Until you answer, the risk screen keeps showing the note that how well this model matches your area has not been checked yet. It is there so the model never looks more certain than it is.

Free and Premium

Rosetare Premium is an auto-renewing subscription, monthly or yearly, with a 7-day free trial. Prices are shown in the App Store and on the purchase screen. There is no free limit on how many records you keep, or on the CSV export. Cancelling never deletes a garden or a zone: you keep reading, editing, deleting and exporting, and only new creation returns to the free limits.

What happens to your data

Rosetare has no account. There are no advertising SDKs and no analytics SDKs, so the developer has no way of knowing how the app is used. Your records live on your device and are never sent to the developer, who runs no server of their own.

It does, however, talk to a weather service. Infection conditions are worked out from hourly temperature, humidity and rainfall, so Rosetare sends your garden's latitude and longitude to Apple's WeatherKit and receives the weather back. That exchange is with Apple, not with the developer. If you never open the weather-driven screens, it never happens.

Spray history exports to CSV, free of charge — ISO 8601 dates, a full stop for the decimal mark, commas between fields, regardless of your language. The CSV is not a backup: it cannot be loaded back in.

What Rosetare does not do

• It does not tell you to spray. There is no "spray now" state.
• It does not recommend products, and holds no database of product names.
• It does not look up a group code from an active ingredient. By design there is no such table in the app.
• It does not judge tank-mix compatibility.
• It has no pest degree-day forecasting.
• It does not sync between devices.
• It shows no disease conditions for a garden that is entirely indoors or under glass, because outdoor weather does not describe those conditions.

Please read

Rosetare is a record-keeping tool. It does not recommend spraying, does not recommend any product, and is not a substitute for the product label or for advice from a qualified adviser. Disease-risk output is an estimate based on published infection conditions, not a validated forecast. Model output is not a substitute for looking at your own plants.

Always read and follow the product label, and follow the pesticide rules that apply where you live.

Requirements

iPhone and iPad running iOS 17.0 or later. Available in English, Japanese, German, French, Spanish, Italian, Dutch and Brazilian Portuguese. Weather by Apple Weather.