GrowByCity is an online gardening resource that helps people plan what to grow and when, using location-specific climate information. It provides free personalized planting calendars for 350 cities worldwide, covering 207 vegetables, herbs, fruits, and flowers. The calendars draw on climate data from NOAA and Open-Meteo, alongside agricultural data from the FAO, to guide planting decisions for different locations.

Gardeners can explore growing guides across seven regions, browse plants and cities, and see which crops may be started now. GrowByCity also offers practical planning tools, including a quiz that recommends plants based on a user’s space, climate, and goals; a frost-date calculator showing frost dates, frost-free days, and planting windows; and a companion planting guide covering 33 plants. Its garden layout planner helps users arrange beds with spacing, sun mapping, and seasonal rotation in mind. Additional resources include planting calendars, spacing guidance, indoor growing advice, beginner and container gardening content, and My Garden features for saving and tracking plants. Together, these tools support gardeners from crop selection through seasonal planning.