Methodology and sources
How Patch builds a planting guide.
Patch aims to give a useful first decision while remaining honest about the local factors a national website cannot see.
Match the location
When a postcode service supplies coordinates and a state, Patch distinguishes coastal, inland, tropical, Mediterranean, semi-arid, arid, warm-temperate and cool-temperate conditions. A postcode-range fallback is used when coordinates are unavailable.
Apply a broad seasonal window
Each plant is assigned a broad month-by-month window for each base climate. Semi-arid and arid suggestions use the overlap between compatible calendars and assume reliable garden watering.
Add practical growing guidance
Planting method, light, maturity, soil, spacing, feeding, maintenance and common problems are combined into a usable starting guide. Some care advice is shared by plant family; it is not a substitute for species- and variety-specific instructions on a packet or nursery label.
Review and correct
Patch marks local guides with extra city-specific research and links to the relevant source. Other city/month pages remain broad climate-calendar tools. Plant pages show a last-reviewed date for their broad guidance, and feedback helps identify regional exceptions and unclear advice for future review.
Sources to check
Authoritative local information comes first.
Important limitation
Microclimates matter
Elevation, frost pockets, coastal exposure, urban heat, shade, rainfall, irrigation and soil can shift a planting window by several weeks.
Safety limitation
Confirm the exact species
Safety notes are cautious prompts, not a complete toxicology database. Contact a veterinarian or the Poisons Information Centre when exposure is suspected.
Last updated 20 September 2026