This is a submission for the Hacktoberfest Open-Source AI Challenge Week 1: Touch Grass
What I Built
Most gardening guides give you advice like "direct sow 2 weeks after the last spring frost" or "start seeds indoors 6 weeks before final thaw". But for everyday people, beginners, and urban balcony growers, this immediately brings friction: When actually IS the last frost in my neighborhood?
That confusion keeps people glued to screens reading conflicting blog posts and confusing agricultural charts instead of stepping outside into the dirt.
I built SOWCAST to bridge that gap and get people off their screens and into the real world with soil on their hands.
SOWCAST is an offline-first, botanical smart garden planner that tells you exactly what to plant THIS WEEK, based on real 20-year historical climate normals for your exact coordinates.
Key Capabilities:
What SOWCAST Can Do:
"This Week" Dashboard: Tells you exactly what to sow right now, what to start indoors, and what to wait on — with clear reasons based on your local soil temperatures.
Frost Countdown & Alerts: Shows a live countdown to your last frost, plus a 48-hour warning before sudden cold snaps so you can protect your young plants.
Works Anywhere on Earth: Automatically adjusts for cold climates with frost dates, or warm/tropical areas with monsoon and dry seasons.
Interactive Garden Bed Planner: Drag and drop plants into a square-foot grid. It warns you about bad plant neighbors and highlights friendly plants that help each other grow.
64+ Curated Plant Guides: Step-by-step instructions for popular vegetables, herbs, and flowers — including spacing, sunlight, watering, and harvest times.
100% Offline & Private: Saves everything directly on your device. Works without internet, needs no login or backend, and installs right onto your phone like a native app.
Demo
Live Deployed App:
Try Demo Garden: You can launch the app and click "Try Demo Garden" on the landing page or dashboard to test it with pre-populated beds and local weather intelligence instantly!Code
Code
The complete source code is open-source on GitHub:
👉 https://github.com/lohanmahima/SOW_CAST
How I Built It
SOWCAST was crafted with a modern, zero-cost, open-source stack designed for 60fps responsiveness and zero maintenance overhead:
Framework & Language: Next.js 14 (App Router) with strict TypeScript, delivering statically optimized pages and seamless client-side hydration.
Design & Micro-interactions: Tailwind CSS with custom editorial botanical typography (Playfair Display + Plus Jakarta Sans), warm cream paper palettes (#F6F1E7), deep moss greens (#2F4A3A), and Framer Motion spring physics for sprout animations, confetti celebrations, and bed drag-and-drop interactions.
The Frost Engine: Connects to the free, keyless Open-Meteo APIs (Geocoding API, 7-Day Weather Forecast, and the 20-Year Historical Weather Archive). It analyzes decades of daily minimum temperatures to calculate the exact 50% probability freeze-thaw boundary.
Client-Side Storage Engine: Powered by Dexie.js (IndexedDB) with relational reactive live queries (useLiveQuery). All user beds, custom plantings, journal photos, growth milestones, and care checklists persist locally on device.
_Autonomous AI Agent Harness: _Built in deep collaboration with an autonomous agentic pair programming harness (Google Antigravity). The agent assisted with mathematical frost curve modeling, synthesizing the companion planting conflict matrix for 64 botanical species, and architecting the square-foot grid coordinate system.
Why Does Open Innovation Matter?
Food growing and climate resilience shouldn't be locked behind proprietary paywalls, opaque subscriptions, or corporate garden apps that sell your data.
_Open innovation made SOWCAST possible in two fundamental ways:
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Open Meteorological Science: The Open-Meteo project provides open-access historical weather data and global forecasts without API keys or rate-limit paywalls. Closed APIs typically charge thousands of dollars for decades of archived minimum temperature readings, pricing out independent developers and hobbyist gardeners.
Browser-Native Standards: Using open web standards—IndexedDB for zero-cloud client storage, Web Push / Notification APIs, Service Workers for PWA offline capabilities, and SVG vector graphics—SOWCAST runs entirely on the user's hardware with zero operational infrastructure costs.
Open innovation proves that individual developers can build production-quality tools that empower people to grow their own organic food and reconnect with nature.
My Agent Session
This project was built from conception to production using the Antigravity agentic coding environment. The agent executed end-to-end full-stack workflows:
Initialized the Next.js 14 App Router architecture and Dexie database schema.
Researched companion planting matrices and built the spatial conflict engine.
Wrote the Open-Meteo statistical freeze calculation algorithms.
Iteratively tested production builds (npm run build), eliminated all TypeScript errors, and packaged PWA service worker manifests.
Prize Categories
Best Overall Project
Getting People Out into the Real World (Bridging technology to dirt, soil, and organic food cultivation)
Best Use of Open-Source AI / Open Innovation Tools
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