GrowCalc

GrowCalc

In-app purchases

About this app

Stop guessing how much fertilizer to put down. GrowCalc turns confusing N-P-K math into a precise, personalized plan — so you apply the right amount, at the right time, for a thicker, greener lawn.

Whether you're a weekend warrior or a lawn-care obsessive, GrowCalc gives you the same precision the pros use, right from your phone.

★ PRECISION NPK CALCULATOR
• Enter your lawn size and product N-P-K — get the exact amount to apply
• See nutrients delivered per 1,000 sq ft in real time (N, P, and K)
• Granular and liquid modes, with automatic dilution rates
• "Cocktail" mode to combine multiple products in a single application

★ PRODUCT LIBRARY
• Save your fertilizers, fungicides, herbicides, pre-emergents and more
• Track N-P-K, bag size, price, application rates and notes
• Color-coded categories and quick search

★ APPLICATION LOG & REMINDERS
• Log every application by product and zone with date and notes
• History grouped neatly by product, with reapply reminders
• Never double-apply or forget a treatment again

★ SOIL pH TRACKING
• Record and chart soil pH per zone over time
• Spot trends and keep your soil in the optimal range

★ LOCAL WEATHER & SOIL TEMPERATURE
• Enter your ZIP code for current conditions and a 7-day forecast
• Soil temperature readings to time pre-emergents and seeding
• Smart spray-window guidance based on wind and rain

★ GROWING DEGREE DAYS (GDD)
• Track weed, pest and fungus pressure windows for your region
• Get watering guidance and the best days to spray

★ TOOLS THAT JUST HELP
• Lawn size converter (sq ft, acres, m²)
• Sprinkler calibration ("tuna can" test) for even watering
• Season archives — snapshot, export to CSV, and start fresh each year
• Full data backup and restore

GROWCALC PRO
Unlock the full toolkit — Dashboard, Product Library, Application Logs, Backups, and Season Archives — with a free trial. Subscriptions are billed through your app store account and renew automatically unless cancelled.

WHY GROWCALC?
• No more spreadsheets or label math
• Built for real lawns, real products, and real conditions
• Private by design — your data stays tied to your account, and we never sell it

Download GrowCalc and give your lawn the precision it deserves.

What’s new

New Arbor tree & shrub care: add trees from our library or ID them by photo with AI, then log watering, feeding, pruning and pH — with reminders and a growth photo journal.
Also: feed dates now recalculate from your actual logs, tree and Products screens load much faster, keyboard and sticky Save buttons behave properly, Ready-to-Spray products show nutrients delivered, and the blank Bag size panel is fixed.
Minor Bugs found fixed, and the app performance have been improved.