What to Grow in a 5-Gallon Bucket — and the Four Crops That Don't Fit

The most useful tool on Earth

Before the crops, the thing itself. University of Maryland Extension opens its container guidance with a sentence you do not expect from a land-grant university: the ubiquitous five-gallon plastic bucket is considered by some to be the most useful tool on Earth, particularly in economically disadvantaged countries.

They follow it with the part that stings. In the US, thousands of them are buried in landfills or burned every day, and thrifty gardeners rescue them from local businesses instead.

So this is a guide about a free object. That matters for what follows, because the honest answer to "what fits in a bucket" is sometimes two buckets, and that is only a real answer if the second one costs nothing.

What a bucket is exactly right for

Five crops, and you can stop reading here if one of them is what you came for: bush beans, carrots, Swiss chard, cherry tomatoes and cabbage. Maryland puts the first four at two gallons and cabbage at exactly five, so a bucket covers all of them with nothing left over that matters.

Below two gallons a bucket stops being right and starts being generous. Radishes are listed at one pint — a bucket holds forty of those. Leaf lettuce and beets want half a gallon. You can grow all three in a bucket and you will be hauling around ten times the soil the plant asked for.

The bucket earns its place in the middle of that range, on the crops where five gallons is the number rather than a rounding-up.

Every crop Maryland gives a number for

Thirteen crops, from their "Minimum container size for common vegetables" table. The verdict column is ours; the volumes are theirs.

Minimum container volume by crop (University of Maryland Extension), against one five-gallon bucket
Crop	Smallest container	One bucket?
Radishes	1 pint	Room to spare — a bucket is 40× this
Beets	½ gallon	Room to spare
Lettuce (leaf)	½ gallon	Room to spare
Beans (bush)	2 gallons	Room to spare
Carrots	2 gallons	Room to spare
Swiss chard	2 gallons	Room to spare
Tomatoes (cherry)	2 gallons	Room to spare
Cabbage	5 gallons	Exactly one bucket
Cucumbers	5 gallons	Exactly one bucket — but see below
Eggplant	5 gallons	Exactly one bucket — but see below
Peppers	5 gallons	Exactly one bucket — but see below
Tomatoes (standard)	5 gallons	Exactly one bucket — but see below
Squash (summer)	10 gallons	No. Two buckets' worth

Summer squash does not fit, and that is worth saying out loud

Ten gallons. Two buckets' worth of soil for one plant, from the same table that gives a pepper five.

Almost nothing written about container gardening says no. Every list is a list of what you can grow, because a page that tells you to go away is a page you close. So here is the no: a five-gallon bucket is half the container a summer squash asks for. It is a big plant with big leaves losing water all day, and half the soil holds half the water it has to draw on between one watering and the next.

If you have two buckets and a saw, you have ten gallons. That is the honest fix and it costs nothing.

Where Maryland's own two pages disagree

Here are Maryland's two answers side by side, which neither of their pages does — the two do not link to each other, so you land on one figure or the other and never learn there is a second. It decides four of the most common crops in the country.

Maryland answers the container question twice. One page carries the per-crop table above, where a standard tomato needs five gallons. A second page skips crops entirely and sorts plants into three size classes, and there the rule reads: For Large Vegetables — one plant per container. Minimum 8-10 gallons of growing media, with a depth of 12-16 inches. The examples given are tomatoes, pepper, eggplant, cucumber and winter squash.

So the same extension service puts a tomato at five gallons on one page and eight to ten on the other. Both say minimum. The five-gallon bucket sits precisely in the gap.

Our reading, and we are labeling it as a reading rather than something they publish: five gallons is where the plant lives and eight to ten is where it does well. A pepper in a bucket is a real pepper plant that will make real peppers. A pepper in ten gallons makes more of them, because the thing a bigger container actually buys you is water — more soil holds more of it, and a container plant that dries out between waterings is the commonest way this goes wrong.

Which means the bucket is not a bad container for a tomato. It is the smallest container that is not a mistake, and knowing that is different from being told five gallons is the answer.

A bucket is deep enough. It is not wide enough

Look at Maryland's large-vegetable rule again and there are two numbers in it, not one: eight to ten gallons of volume, and a depth of twelve to sixteen inches.

A standard five-gallon bucket stands about fourteen inches tall, so filled to within an inch of the rim it sits inside that twelve-to-sixteen-inch band. The depth is not the problem. The volume is — and you cannot fix a volume problem by digging deeper, because the bucket already meets the depth the rule asks for.

That is the whole geometry of the thing. A bucket is a tall narrow column of soil, and a tomato root system is not shaped like that.

Making a bucket into a container that works

Four things, and only the first is non-negotiable.

Drill the drainage holes. A bucket has none until you make some. Maryland is blunt that every container except a self-watering one needs them: without drainage the roots drown and rot, and fertilizer salts build up in the soil with nowhere to flush to. Half a dozen holes in the base, any bit you own.
Check the number stamped on the bottom. If you are growing food in a rescued bucket, Maryland says to use one rated food-grade and to avoid #3 plastic, which is PVC. Numbers 2, 4 and 5 are the safe ones — high-density polyethylene, low-density polyethylene and polypropylene. The code is molded into the base of almost every bucket made.
Fill it with potting mix, not garden soil. Soil weighs about 75 pounds per cubic foot and is too dense to let air and water move around roots in a container. It can also bring weed seeds and pathogens in with it. One 2-cubic-foot bag of potting mix fills three five-gallon buckets, which is the arithmetic you need standing in the aisle.
Get it off the ground. Bricks, scrap lumber, or the pot feet garden centers sell. Water has to leave the bottom of the bucket, and a bucket sitting flat on a patio is a bucket whose drainage holes are against concrete.

One warning worth repeating from Maryland: plastics not made for outdoor use get brittle in sun and weather. A bucket that has spent three summers outside can crack when you lift it by the handle, usually while full.

What a bucket will never do

Two hard limits, so this page is not another list of things you can grow.

The perennials are out of reach. Maryland's own figures put dwarf fruit trees at 25 to 30 gallons of potting mix and shrubs at 25. Our own sourced records say much the same for the fruit people ask about most — a currant wants 15 gallons, a mandarin 15, a raspberry 20 to 30. There is no arrangement of five-gallon buckets that makes an apple tree work.

A bucket dries out faster than the ground. Less soil, more surface area, and a container sitting in full sun. In July that is a daily job rather than a twice-a-week one, and it is the reason the volume question matters more than any other number on this page.

For the crop most people try first, how to grow tomatoes in pots works through the size question and the variety mismatch that stalls container tomatoes in July. And potatoes in a bucket is the one crop where somebody does publish a per-plant number, which is why it gets its own page.

Questions about growing in buckets

What vegetables grow best in a 5 gallon bucket?

Bush beans, beets, carrots, Swiss chard, cabbage and cherry tomatoes. All six sit at or below five gallons in Maryland Extension's minimum container size table, so a bucket is the right container rather than a compromise. Peppers, eggplant, cucumbers and standard tomatoes will also grow in one — five gallons is their listed minimum — but Maryland's size-class guidance puts those four at eight to ten gallons for one plant, so a bucket is the floor rather than the ideal.

How many plants can I put in one 5 gallon bucket?

Nobody publishes that crop by crop, which is the honest answer. Maryland states it only for its large-vegetable class — tomatoes, peppers, eggplant, cucumbers and winter squash are one plant per container. For potatoes, New Hampshire Extension gives five gallons of soil per plant, so a bucket holds exactly one. For everything else you are working from spacing rather than a published figure, and we would rather say so than hand you a number we worked out ourselves.

Can you grow squash in a 5 gallon bucket?

Not well. Maryland lists summer squash at ten gallons minimum, which is two buckets' worth of soil for one plant. It will grow — it will also run short of water at exactly the point the fruit is setting, and squash short of water aborts its fruit rather than shrinking it. If buckets are what you have, use two joined together or find a ten-gallon container. Winter squash is in Maryland's large-vegetable class and wants the same eight to ten gallons.

Do I need to drill holes in a 5 gallon bucket?

Yes, before you fill it. Maryland says every container except the self-watering kind needs drainage, for two reasons: roots sitting in water rot, and fertilizer salts collect in the soil with no way to flush out. Half a dozen holes in the base is enough. Then raise the bucket off the ground on bricks or pot feet, because a drainage hole pressed against a patio is not draining.

Are 5 gallon buckets safe for growing food?

Use one rated food-grade and check the recycling number molded into the base. Maryland says to avoid #3, which is PVC, and names #2, #4 and #5 as safe to use — high-density polyethylene, low-density polyethylene and polypropylene. Buckets from restaurant kitchens and bakeries are usually food-grade already, which is where the tradition of rescuing them comes from.

How much potting mix fills a 5 gallon bucket?

A 2-cubic-foot bag fills three of them, which is Maryland's own figure and the most useful thing to know standing in a garden center. Use potting mix rather than garden soil: soil runs about 75 pounds per cubic foot and is too dense to let air and water move around the roots in a container, and it can carry weed seeds and pathogens in with it.

Sources

Every planting date, depth, and temperature on this page traces to these university extension guides. Where they differ, the ranges above hold the whole spread.

University of Maryland Extension, Home & Garden Information Center — Growing Vegetables in Containers and Salad Tables
University of Maryland Extension, Home & Garden Information Center — Types of Containers for Growing Vegetables
University of New Hampshire Extension — What is the best way to grow potatoes in containers?

A bucket is the cheapest way into growing food, and the useful question is not whether a crop will survive in one but whether five gallons is its number or merely its minimum. For five crops it is the number. For four more it is the floor.

The other half of the question is what a bucket will not do — and if it is fruit you are after, start with pollination rather than pot size.

Every number on this page comes from Maryland Extension directly, and both pages are linked above so you can read them yourself. We hold a container size for 143 crops and mark which ones carry a citation — 28 do today, and a value without one says so rather than pretending. It is all in the free plant database if you would rather check us than take our word for it.