GrowScore rates every plant 1–100 based on how well it matches your specific location. Here’s exactly what goes into that number — and what it can’t tell you.
Each GrowScore is calculated from six climate and growing variables. Together, they paint a realistic picture of how a plant will perform in your specific location.
Your USDA hardiness zone (1–13, with sub-zones a/b) tells us the average annual minimum winter temperature. Each plant has a minimum survival zone — if yours is colder, it won’t make it through winter without protection.
Summer heat stress is increasingly important in zones 7–10 and above. Plants that can’t handle sustained high temperatures will struggle even if they survive winter. We factor in both average summer highs and the number of days above the plant’s heat threshold.
Plants have ideal rainfall ranges — too little and they need constant supplemental irrigation; too much and they risk root rot and fungal issues. GrowScore compares your regional average precipitation against the plant’s water needs to score how well the natural moisture aligns.
Soil acidity (pH 0–14) affects whether plants can access key nutrients. Blueberries need acidic soil (4.5–5.5); many vegetables prefer near-neutral (6.0–7.0). GrowScore uses regional soil survey data to estimate your area’s baseline pH and scores plants accordingly.
Days from last spring frost to first fall frost — and whether that window is long enough for the plant to grow from transplant or direct-sow to harvest. A tomato that needs 75 days to mature will score poorly in a short-season zone even if it survives winter.
Full sun (6+ hours), partial shade (3–6 hours), or full shade (under 3 hours). Most vegetables need full sun; many herbs tolerate partial. The score reflects how well your area’s typical light exposure matches the plant’s preference.
GrowScore runs 1–100. Here’s how to read it — and why context matters.
Honesty is part of the score. Here’s what we explicitly don’t account for.
We estimate regional pH but don’t know your garden’s actual clay, sand, or loam content. Get a soil test for accurate data.
A south-facing wall, concrete patio, or hillside can be 2–3 zones warmer than your ZIP code suggests. Your yard may differ from your neighborhood.
Late spring frosts, summer hailstorms, and drought years happen. No model can predict the anomaly year — only the typical conditions.
Regional pest burdens vary. Deer, gophers, tomato hornworms, and powdery mildew hotspots are highly local and not modeled.
Two gardeners 30 miles apart can see wildly different results from the same plant. Here’s why location matters so much — and why a ZIP code or postal code is just the start of the story.
Hot summers, mild winters, long growing season. Tomatoes love it — but need heavy watering and afternoon shade in the peak of summer.
Same zone, completely different climate. Cool summers, heavy spring rain. Tomato production is lower; blight risk is higher.
Zone alone explains only part of the score. Heat tolerance, rainfall patterns, and season-length data all vary within the same USDA zone. That’s why GrowScore layers six factors — not just the zone label.
Pick a plant and enter your ZIP code or postal code to get a personalized GrowScore based on your actual conditions.