About WhatCanGrow

Most gardening sites bury the one thing you need behind a wall of prose. WhatCanGrow answers it in seconds: what will survive and thrive in your specific location? Tell us your city, state, or zone, and we give you your hardiness zone, first and last frost dates, and a color-coded list of what grows well, what's borderline, and what won't make it — plus when to plant each one.

What you get, on every page

• Your zone — USDA (US) or Canadian (NRCan) hardiness zone for your location.
• Frost dates — average last spring frost and first fall frost, so you know exactly when to act.
• Growing-season length — how many frost-free days you actually have.
• The verdict — "grows well," "borderline," "grow indoors," or "won't grow," calculated from the plant's real hardiness range against your zone.
• When to plant — seed-starting, transplant, and harvest windows tied to your frost dates.

How we calculate the verdict

Every plant has a verified hardiness range — for example, tomatoes grow in USDA zones 4a through 11b. We compare that range to your zone:

• Inside the range → "grows well."
• One half-zone out, and the plant is frost-tolerant → "borderline" (it might work with care).
• Close, and it grows in a container indoors → "grow indoors."
• Outside the range → "won't grow" — because telling you the truth beats recommending a plant that'll die.

We also handle the edge cases honestly: perennials and fruit trees that take multiple years to establish don't get a misleading "days to harvest" number; garlic and fall-planted crops use an autumn schedule, not a spring one.

The US vs. Canada scale — an important difference

Canada uses a different hardiness formula than the US. USDA zones are based only on average annual minimum temperature (zones 1a–13b). Canada's NRCan zones (0a–9a) factor in cold, frost-free days, snow cover, rainfall, and wind. A Canadian "zone 5" is not the same as a US "zone 5" — they're systematically offset. We keep the two scales separate and label each clearly so you never mix them up.

What we don't do

We don't publish a "zone" or "frost date" we can't point to a source for, and we don't pretend a one-size answer exists for a huge state like California (which spans zones 5a to 11a). Our state and province maps are colored by their most common zone, with a note pointing you to the precise zone pages for your exact spot.

WhatCanGrow is part of Gravison Group.