Gardening
How Far Apart to Plant Trees
The gap that looks absurd on planting day is the one that looks right in fifteen years. Space on the mature spread, not the size in the pot.
Aug 3, 2026 · 4 min read
Category
Gardening
Beds, lawns, and what to plant when — working out what a garden actually needs.
26 tools · 26 articles
Free Gardening tools
Cover Crop Seed Calculator
Turn your seed bag's own rate into the amount for your beds, with the broadcasting increase and the bags you actually have to buy.
Open the tool →Drip Irrigation Zone Calculator
How many emitters your supply can actually run at once - measured with a bucket and a stopwatch, not assumed from a table.
Open the tool →Firewood Drying Time Calculator
When your wood is ready to burn - on the EPA's seasoning baseline of six months for softwood and a year for hardwood, with the moisture meter as the real test.
Open the tool →Growing Season Fit Calculator
Does the crop actually fit your season? Enter your frost-free days and its days to maturity, and see the slack - or how short you are.
Open the tool →Crop Rotation Planner
Work out which bed a crop family moves to in any future year, and whether your number of beds actually gives the rest interval you need.
Open the tool →Lime Rate Calculator
Convert your soil test's lime recommendation into bags of the product you actually bought - adjusted for its CCE, and split if the rate is too high for one go.
Open the tool →Greenhouse Heater Size Calculator
Heat loss from your glazing's own U-value and your own design low - the two numbers that decide heater size, and neither of them is guessable.
Open the tool →Hydroponic Nutrient Mixing Calculator
Scale your bottle's own dose rate to your reservoir and your top-ups - including the ml/gal against ml/L conversion that is a factor of 3.79.
Open the tool →Mushroom Substrate Calculator
Water to add for your target moisture, and spawn to match - worked from dry weight, which is the only figure that stays put.
Open the tool →Pond Liner Size Calculator
Liner size from your pond's dimensions - remembering that the depth is added twice, once going down each side, plus the overlap you bury.
Open the tool →Potting Mix Ratio Calculator
Turn a parts recipe into real volumes for a batch of pots - and buy in DRY quarts, which are 16% bigger than the liquid ones.
Open the tool →Rain Barrel Capacity Calculator
How much water a roof actually sheds per inch of rain, how little of it one barrel holds, and how many you would need to catch the lot.
Open the tool →Seed Starting Date Calculator
Work the indoor timeline backwards from your own last frost date - sowing, emergence, hardening off and planting out, all in days you can count on a calendar.
Open the tool →Sprinkler Coverage Test Calculator
Run a catch test with five tins and get two numbers: your sprinkler's real output rate, and how evenly it actually covers the ground.
Open the tool →Tree Spacing Calculator
Space trees on their MATURE spread, not the size in the pot - and keep them off the house by half a canopy plus clearance.
Open the tool →How Many Plants to Grow Calculator
Work back from how much you actually eat to how many plants to sow - with a loss allowance, because not every plant makes it.
Open the tool →Compost Brown-to-Green Ratio Calculator
The famous 30:1 is carbon to nitrogen BY WEIGHT. What you actually measure is roughly 3:1 browns to greens BY VOLUME — two different numbers for one rule.
Open the tool →Garden Edging Calculator
Linear feet, pieces and stakes for a bed border - including the bit people forget, which is that a bed against a wall does not need edging all the way round.
Open the tool →Grass Seed Calculator
Seed is sold by weight but applied by rate, and the rate belongs to the grass - bluegrass goes down at a quarter of the fescue weight, and twice the seeds.
Open the tool →Lawn Fertilizer Calculator
You apply pounds of NITROGEN, not pounds of fertilizer. A 16-4-8 bag needs 6.25 lb to deliver 1 lb of N - and that ratio is the whole calculation.
Open the tool →Plant Spacing Calculator
How many plants fit a bed at your chosen spacing, laid out in rows — so you buy the right number instead of guessing.
Open the tool →Raised Bed Material Calculator
Boards for a raised garden bed - and the height it will really end up, which is taller than the one you asked for and needs more soil than you planned.
Open the tool →Raised Bed Soil Calculator
How much soil a raised bed needs, in cubic feet, cubic yards and bags — for one bed or a whole plot.
Open the tool →Sod Calculator
How much sod your lawn needs and how many pallets that is - plus the constraint no other material has, which is that it is alive and on a clock.
Open the tool →Lawn & Garden Watering Calculator
An inch of water over 1,000 sq ft is 623 gallons. Work out how long your sprinkler needs — and measure its real output with a tuna can.
Open the tool →Mulch Calculator
Work out how much mulch a bed needs in cubic yards and bags, from its size and how deep you want to go.
Open the tool →Gardening articles
Gardening
How Many Drip Emitters Can One Line Run?
Time your tap filling a bucket and the answer falls out. But flow is only half the problem — the other half is how far the water has to travel.
Aug 3, 2026 · 4 min read
Gardening
How Many Vegetable Plants Do I Need?
Sowing to fill the space you have is how gardens end up with forty lettuces in one fortnight and nothing in September. Work back from what you eat.
Aug 3, 2026 · 3 min read
Gardening
How Much Cover Crop Seed Do I Need?
The rate is on your bag, and it has to be — clover and cereal rye differ by an order of magnitude for the same ground. The arithmetic after that is easy.
Aug 3, 2026 · 4 min read
Gardening
How Much Water Can You Collect From a Roof?
One inch of rain on an ordinary house roof is over 700 gallons. A 55-gallon barrel catches under a tenth of it, and that's not the barrel's fault.
Aug 3, 2026 · 4 min read
Gardening
How to Convert a Lime Recommendation Into Bags
Your soil test gives a rate in pure calcium carbonate. Your bag isn't pure — at 75% CCE you need a third more than the report says.
Aug 3, 2026 · 4 min read
Gardening
How to Mix Hydroponic Nutrients by Reservoir
Never pour one concentrate into another. Calcium and sulphates meet at full strength, drop out of solution, and take the nutrients you paid for with them.
Aug 3, 2026 · 3 min read
Gardening
How to Mix Your Own Potting Soil
A parts recipe scales to any batch — but potting mix is sold in DRY quarts, which are 16% bigger than the liquid ones people convert from.
Aug 3, 2026 · 4 min read
Gardening
How to Plan a Crop Rotation
Your number of beds is your rotation length — four beds is a four-year gap, and no clever planting order changes that.
Aug 3, 2026 · 4 min read
Gardening
How to Test Your Sprinkler Coverage
A zone can average exactly the right depth and still have a corner getting a fraction of it. The average hides that completely.
Aug 3, 2026 · 4 min read
Gardening
How to Work Out Mushroom Substrate and Spawn
Weigh dry, not wet. Substrate arrives at whatever moisture the supplier's shed had, so a wet-weight recipe is never repeatable.
Aug 3, 2026 · 3 min read
Gardening
What Size Heater for a Greenhouse?
Heat loss is area times U-value times temperature gap. The physics is trivial — the two numbers it needs are the part nobody can guess for you.
Aug 3, 2026 · 4 min read
Gardening
What Size Pond Liner Do I Need?
A 10 ft pond needs a 16 ft liner. The depth goes in twice — down one side and up the other — and that's the surprise that sends people back to the shop.
Aug 3, 2026 · 4 min read
Gardening
When Is Firewood Actually Ready to Burn?
Six months for softwood, a year for hardwood - and the clock starts the day you split it, not the day the tree came down.
Aug 3, 2026 · 5 min read
Gardening
When to Start Seeds Indoors
Starting early is the more expensive mistake. A seedling held waiting for weather goes leggy, and gets overtaken by one sown a fortnight later.
Aug 3, 2026 · 3 min read
Gardening
Will This Crop Fit My Growing Season?
Maturity is the first harvest, not the last. A crop that ripens exactly at the first frost gives you one picking rather than a season of them.
Aug 3, 2026 · 3 min read
Gardening
Compost Brown to Green Ratio
30:1 and 3:1 are the same rule in different units — carbon to nitrogen by weight, browns to greens by volume. Mixing them up builds a heap that does nothing.
Jul 31, 2026 · 4 min read
Gardening
How Long Should I Water My Lawn?
An inch of water over 1,000 sq ft is 623 gallons. But the number that decides your answer is your sprinkler's real output — and it takes one empty can to find.
Jul 31, 2026 · 4 min read
Gardening
How Many Plants Fit in a Bed?
Rows times plants per row — not area divided by spacing. The arithmetic, why packet spacing looks too wide, and what offsetting the rows buys you.
Jul 31, 2026 · 4 min read
Gardening
How Much Fertilizer for My Lawn?
The rate is 1 lb of NITROGEN per 1,000 sq ft — which is 6.25 lb of a 16-4-8 bag. Confuse the two and you're out by a factor of six.
Jul 31, 2026 · 4 min read
Gardening
How Much Garden Edging Do I Need?
A bed against a wall needs three sides, not four. Counting them before ordering is the biggest saving available — and it takes one look at the bed.
Jul 31, 2026 · 4 min read
Gardening
How Much Grass Seed Do I Need?
Bluegrass goes down at a quarter of the fescue rate by weight - and still puts two and a half times more seeds on the ground. Both are true.
Jul 31, 2026 · 4 min read
Gardening
How Much Lumber Do I Need for a Raised Garden Bed?
Six boards for an 8×4 bed — and the bed will be 14½ inches tall, not the 12 you designed. That difference is a fifth more soil than you planned to buy.
Jul 31, 2026 · 4 min read
Gardening
How Much Sod Do I Need?
Area plus waste, divided by the pallet. But sod is the one material where buying extra is the wrong advice — because it's alive and on a clock.
Jul 31, 2026 · 3 min read
Gardening
How Much Soil Do I Need for a Raised Bed?
A bed is a box, so it's length × width × depth. The arithmetic, how deep it actually needs to be, and why it looks lower next spring.
Jul 31, 2026 · 5 min read
Gardening
How Much Mulch Do I Need?
Mulch is sold by volume, so the answer is length times width times depth. Here's the arithmetic, the conversions, and where people get it wrong.
Jul 30, 2026 · 4 min read