Smart garden management starts with measurement. Temperature, air and soil humidity, rainfall, and UV index: connected sensors transform your garden into a real-time data environment. This information can trigger automatic watering, anticipate frost, or help you adapt fertilization schedules. We present and compare the best weather stations (Netatmo, Ecowitt, Ambient Weather) and soil sensors compatible with major smart home platforms: Home Assistant, Apple Home, and Google Home. A practical guide to choosing based on your existing ecosystem and budget.