Turf: Lawn Care Calculator — Support

Need help?

Email roman.kopaliani@gmail.com with your question. Please include:

• What you were trying to do
• What happened
• The iOS version and iPhone or iPad model you're using (Settings → General → About)
• The app version (Turf → More → About)

Common questions

What's free, and what does Turf Pro add?

The Nitrogen-rate calculator is free permanently: enter your fertilizer's nitrogen percentage, your target rate, and your lawn size, and Turf tells you how much product to put down — with a guardrail if you exceed the per-application nitrogen cap. Turf Pro ($4.99, one-time) unlocks the other five calculators: spreader-setting calibration, liquid dilution / tank-mix, lime & sulfur soil-pH amendment, grass seed rate, and PGR growing-degree-day timing. No subscription.

Where do the numbers come from?

Every figure is cited to a primary university-extension source — Purdue, Virginia Cooperative Extension, Clemson HGIC, Penn State, Michigan State, University of Minnesota, NC State, Cornell, and Texas A&M — plus US EPA pesticide-label guidance and the Kreuser & Soldat growing-degree-day model. The app names the source next to each number. Turf is brand-agnostic: it doesn't sell you fertilizer.

Why doesn't the lime calculator give one exact number?

Because the sources don't support one. The widely-repeated "sand 25 / loam 75 / clay 100" lime table traces only to commercial calculators, not to any primary extension publication. Turf instead shows the cited turf topdress band (25–50 lb of ground limestone per 1,000 sq ft per application, per Michigan State E-471), with a per-application cap, and treats soil texture as context — full pH correction takes more than one application and a year or two. Soil-test, apply, and re-test.

Why does the PGR calculator warn about putting greens?

The 200 growing-degree-day reapplication target for trinexapac-ethyl (Primo Maxx / T-Nex) is validated in the research specifically for creeping-bentgrass putting greens, not home lawns. Turf surfaces that caveat so you treat it as a general timing guide and follow your product label, rather than a guaranteed home-lawn number.

How do the spreader and dilution calculators work?

Spreader settings are device-specific — the same product reads differently on every spreader — so Turf gives you the calibration method (catch-and-weigh over a measured strip) rather than inventing a dial number. The liquid-dilution calculator turns a product's label rate into ounces per gallon for your measured sprayer output. Always apply at the product-label rate: the label is the law.

I bought Turf Pro on another device. How do I restore?

Open More → Restore Purchases. Your unlock will be restored from the App Store account that originally purchased.

Does the app work offline?

Yes — Turf never makes general network requests. The exceptions are Apple's StoreKit (to fetch the unlock price and restore purchases) and the cited source links you tap (which open in Safari). All calculations and preferences are local.

Is Turf a guarantee?

No. Turf is an educational reference calculator that shows published extension guidance alongside your inputs. Soil, grass, climate, and products vary — confirm with your product label and your local cooperative-extension office, and soil-test before amending pH.

How do I delete my data?

Delete the app from your iPhone or iPad. All local data (preferences) is removed along with it.