Free Garden Tools
50 free calculators, planners and trackers for home gardeners. Soil, water, seed, spacing, crop planning and vegetable prices: each one answers a single question and shows its working. Free, no sign-up, runs in your browser.
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Climate & Timing (8)
Zones, frost dates, and the weather numbers that set your planting window.
Planting Zone Finder
Pick your USDA Hardiness Zone and see its minimum temperature, season length, frost-free window, and example crops.
First Frost Date Calculator
Find your average first fall frost date by zone, so you know when tender plants need protection.
Last Frost Date Calculator
Find your average last spring frost date by zone, so you know when it is safe to plant out.
Growing Degree Days Calculator
Add up heat units from daily temperatures to predict growth, flowering, and harvest dates.
Chill Hours Calculator
Count the hours below a temperature threshold to check whether a fruit variety gets the winter chill it needs.
Sun Exposure Calculator
Estimate the hours of direct sun a bed or spot receives, from its direction and shade.
Australia Planting Zone Finder
Find your Australian hardiness zone by postcode or on the map, from 1991 to 2020 climate data. Zones 8 to 13, in Celsius.
Interactive Planting Zone Finder UK
Find your UK hardiness zone by postcode district or on the map, from Met Office climate data.
Planning (4)
Lay out beds, plan what goes where, and keep a calendar of what to do when.
Seasonal Garden Calendar
Month-by-month tasks for your zone: what to sow, plant, prune, and harvest all year.
Garden Planner
Lay out your beds on a grid: set spacing, spot companion conflicts, and plan before you dig.
Square Foot Planner
Plan a square-foot bed: one plant per square, or 4, 9, or 16, depending on the crop.
Companion Planting Tool
Look up any plant to see its best companions and the ones to avoid, with the reason for each pairing.
Soil & Compost (9)
Volumes, amendments, and nutrient rates. What to buy and how much to spread.
Compost Recipe Builder
Add greens and browns and watch the carbon-to-nitrogen ratio update live. Aim for 25 to 30:1 for fast compost.
Soil Test Interpreter
Enter your pH, phosphorus, and potassium results and get specific amendment recommendations.
Raised Bed Soil Calculator
Work out the soil volume for a raised bed in cubic yards and bags, split by topsoil and compost.
Topsoil Calculator
Work out the topsoil volume for any area, in cubic yards and bags.
Potting Soil Calculator
Work out the potting soil volume for your pots and planters, in litres, cubic feet, and bags.
Mulch Calculator
Calculate how much mulch you need in cubic yards and bags for any bed area and depth.
Fertilizer Calculator (NPK)
Calculate how much fertilizer product to spread from the N-P-K analysis on the bag and your target nitrogen rate.
Lime Application Calculator
Work out how much lime you need to raise soil pH, by current pH, target pH, area, and soil type.
Manure Application Calculator
Work out how much manure to spread for an area, by dose and manure type.
Beds & Spacing (3)
Size and fill a bed, then work out how many plants fit inside it.
Plant Spacing Calculator
Calculate how many plants fit in a bed at a given spacing, with square and triangular layouts and the seeds to sow.
Garden Bed Calculator
Work out a bed’s area, perimeter, and fill volume, with presets for square, rectangular, and round beds.
Container Size Matchmaker
Look up any plant and get the recommended pot size, depth, material, and drainage.
Seeds & Propagation (5)
Seed quantities, sowing rates, and germination maths for beds and fields.
Seed Germination Calculator
Calculate seed germination percentage and how many seeds to sow for a target number of seedlings.
Seed Starting & Planting Date Calculator
Get indoor sowing, transplant, and direct-sowing dates per crop, from your frost dates.
Seed Rate Calculator
Work out the seed quantity for an area, from the sowing rate and your germination rate.
Seed Stratification Timer
Work out when to start cold stratification from your target planting date and the treatment length per seed.
Transplant Date Calculator
Work out the transplant date from your sowing date and the seedling age per crop.
Crops & Yield (8)
Rotation, succession, and what the harvest should come to.
Crop Rotation Planner
Track plant families per bed and get a warning when the same family returns too soon.
Succession Planting Planner
Plan repeat sowings every few weeks for a continuous harvest.
Crop Yield Calculator
Estimate total harvest from area and yield per plant or per square foot.
Harvest Date Calculator
Estimate the harvest date from your planting date and the days to maturity per crop.
Garden Harvest Value Tracker
Log your harvests and compare their value with grocery store prices.
Harvest Yield Estimator
Estimate total harvest as yield per plant times the number of plants.
Vegetable ROI Calculator
Rank vegetables by dollars saved per square foot, using USDA prices.
Plant Problem Triage
Answer questions about your plant’s symptoms and get possible causes and checks to run.
Water & Irrigation (5)
Drip, sprinkler, and rainwater sizing, plus how much water a planting really needs.
Garden Watering Calculator
Work out weekly water needs by plant type, bed size, and climate, with a watering schedule.
Rain Barrel Calculator
Work out how much rainwater your roof can collect and how many barrels it fills.
Drip Irrigation Calculator
Plan a drip system: emitters, flow rate, and run time in one tool.
Irrigation Scheduling Calculator
Work out irrigation frequency and depth from plant water needs and soil type.
Sprinkler Calculator
Work out how many sprinklers you need and their coverage for an area.
Harvest & Storage (4)
Preserve the harvest, and cost out the job before you start it.
Dehydrating Time Calculator
Find drying temperature, time, and doneness tests for vegetables, fruits, herbs, and more.
Tender-Bulb Overwintering Scheduler
Get dig, cure, and store schedules for tender bulbs by zone and bulb type.
Liquid Fertilizer Dilution Calculator
Calculate how much liquid fertilizer concentrate to mix into a given volume of water at any dilution ratio.
Raised Bed Build Cost Calculator
Estimate the cost of building a raised bed: timber, soil, and mulch for your size.
Lawn & Turf (1)
Grass seed for new lawns and overseeding.
Grass Seed Calculator
Work out grass seed needs for a new lawn or overseeding, by grass type.
Prices & Market (3)
Price trackers for three countries, so you can see what a crop costs before you decide whether to grow it or buy it.
Australia Vegetable Prices
Vegetable prices per kilogram at Woolworths, Coles and Aldi in Australian dollars, checked daily, with a grow or buy guide.
USA Vegetable Prices
Weekly US vegetable prices per pound and per pack, from USDA advertised grocery prices, with week to week trends.
UK Vegetable Prices
Fortnightly UK wholesale fruit and vegetable prices per kilogram, from Defra market data, with two year trends.
Frequently asked questions
Are these garden tools really free?
Yes. All 50 tools are completely free to use with no sign-up, no account, and no paywall. They run entirely in your browser, and your inputs are saved on your own device only.
Do the tools work on mobile?
Yes. Every tool is designed for phones and tablets as well as desktop browsers. On a phone the related-tools panel moves below the calculator instead of sitting beside it.
How accurate are the calculators?
The calculators use standard formulas from US extension service guidelines, and each tool page shows its formula and assumptions. They give reliable estimates for planning. Actual results vary with your soil, climate, and plant varieties.
Which tool should I start with?
If you are setting up a new garden, start with the Planting Zone Finder to establish your zone, then the First and Last Frost Date Calculators for your planting window, then the Raised Bed Soil Calculator to fill your beds. If you are planning what to grow where, the Garden Planner and Companion Planting Tool are the best starting points.
