Growing Tomatoes in 5-Gallon Buckets, With a Watering System

Growing Tomatoes in a 5-Gallon Bucket: The Short Answer

Tomatoes grow well in a 5-gallon bucket when you plant one per bucket, give it at least 6 to 8 hours of direct sun, and keep the mix evenly moist. The watering is the hard part. A bucket in full summer sun needs water at least once a day and sometimes twice, so most growers end up building a watering system. The two that suit buckets are a reservoir under the mix (a self-watering bucket) and a drip line on a timer. Both are covered below, after the basic setup.

University of New Hampshire Extension recommends one tomato plant per four or five-gallon container. University of Maryland Extension lists 5 gallons as the minimum for a standard tomato and 2 gallons for a cherry type. A 5-gallon bucket therefore sits at the floor for a full-size plant, which is why variety choice and steady watering matter more here than in a garden bed.

Pick a Variety Sized for 5 Gallons

Determinate tomatoes are the easy fit. They grow to a set height and stop, then flower and fruit over a short period, with the whole crop picked within four to six weeks. Indeterminate tomatoes keep growing and fruiting until the first frost, so they ask more of a small root zone. Determinate vs. indeterminate tomatoes explains the difference in more detail.

Named container picks from extension lists include ‘BushSteak’, ‘Celebrity’, ‘Tumbling Tom’ and ‘Tiny Tim’. ‘Bush Early Girl’ stays below 3 feet tall, and ‘Patio Choice Yellow’ reaches only about 18 inches. Clemson Extension notes that a 14-inch to 20-inch container suits most compact cultivars and that a five-gallon bucket with holes drilled in the bottom does the same job.

In a short season, look at days to maturity on the plant tag. Early cultivars ripen 55 to 65 days after transplanting, and the general range for tomatoes is 65 to 90 days. Colorado State University Extension suggests choosing a variety listed under 75 days for bucket growing where summers are brief.

How to Set Up a 5-Gallon Bucket for Tomatoes

1. Clean and disinfect the bucket.
2. Make 3 to 5 holes in the bottom for drainage. If the bucket will sit flat on a patio, drill the holes along the side instead, 1/4 to 1/2 inch from the bottom.
3. Fill the bucket about one quarter full with soilless potting mix.
4. Set one tomato plant in the center and strip the leaves from the part of the stem that will be buried. Roots form along a buried stem and help hold the plant up.
5. Add mix around the stem until only two or three sets of true leaves show. After watering in, the surface should sit about 2 inches below the rim so water does not run over the edge.
6. Put the support in right away, then mulch the surface with straw, shredded leaves or fine pine bark.

Use a bagged soilless mix. Garden soil packs down in a container and drains poorly. Skip the gravel layer too: adding rocks, gravel or broken pot shards to the bottom of a container does not improve drainage, a point covered in rocks in the bottom of a pot. Fill the whole bucket with mix, and see the best potting mix for containers if you are choosing a bag.

Timing follows the same rule as garden tomatoes. Wait until the danger of frost has passed and the soil has warmed to about 60°F. A bucket has one advantage over a bed here, because you can carry it indoors on nights when the temperature drops below 50°F. For regional dates, see when to plant tomatoes outside.

Dark containers can raise the temperature of the mix enough to injure tender roots. A white or light-colored bucket is the safer choice for a spot in full summer sun.

Stake the Plant on Planting Day

Any cultivar that grows taller than 2 feet needs support. The Colorado State method notes that tomato cages are usually not tall enough and calls for staking at least 4 feet high, using tall stakes and twine or a cylinder of strong fence wire fitted around the bucket. Drive a stake 4 to 6 inches from the stem soon after transplanting, before roots fill the mix. Tomato cages and stakes compared covers the options.

On an indeterminate variety, prune out the side shoots that form in the leaf axils. That sends the plant’s resources to the main stem and lets sunlight reach the fruit. Checking weekly is enough, and it keeps the plant more manageable in a bucket. Determinate and compact bush varieties stop at a set height and are usually left unpruned.

Watering by Hand: The Baseline

Before choosing a system, know what it has to deliver. Check the bucket every day. Once the top two inches of mix are dry, apply water until it begins to drain from the holes. In the height of summer that means watering thoroughly at least once a day, possibly twice.

A mulch cap slows evaporation from the surface. Steady moisture also protects the fruit, because swings between soaked and dry mix are tied to blossom end rot. If you want a fuller routine for beds and pots, how to water tomatoes has one.

System 1: A Self-Watering Bucket With a Reservoir

A self-watering bucket has no holes in the bottom. The mix sits on a perforated platform above a pool of water, and one overflow hole in the side stops the water from rising too high. Water wicks up into the mix, and roots grow down through the platform into the reservoir.

University of Maryland Extension publishes a design that uses one 5-gallon bucket and its lid. The lid is cut down to fit inside the bucket and drilled with 15 holes, each 5/16 inch across. Three pieces of 4-inch perforated drain tile, each 2 1/2 inches long, stand on the bucket floor and hold the lid up. One 3/4 inch hole is drilled in the side, 2 inches above the bottom, and a 6-inch length of 1/2 inch tubing carries the overflow into a milk jug. The bucket is raised 8 inches on a cinder block or bricks so the tube can reach the jug, and the collected water is poured back before new water is added.

To use it, fill the bucket with about 4 gallons of moistened mix, plant, and add 2 to 3 gallons of water. In July and August, in full sun, it takes 1 to 2 quarts of water each day to refill the reservoir. That is still a daily visit, but it is a quick pour, and the plant draws water all day between visits. Self-watering planters vs. regular pots weighs the trade-offs if you would sooner buy than build.

System 2: Drip Irrigation on a Timer

A drip line suits a row of buckets. One supply tube runs past the buckets, a short branch with an emitter drops into each one, and a timer at the faucet opens the valve on a schedule. The buckets keep their ordinary drainage holes.

Set the timer to do what hand watering does: wet the whole root zone until a little water drains out, once a day in summer, with a second cycle during heat. Then check the mix two inches down for the first week and adjust the run time. Drip irrigation kits for small gardens explains the parts.

	Hand watering	Self-watering bucket	Drip on a timer
Holes in the bucket	3 to 5 in the bottom	One overflow hole, 2 inches up the side	3 to 5 in the bottom
Summer routine	Water once or twice a day	Add 1 to 2 quarts a day	Check the mix, adjust the timer
Best for	One or two buckets	A few buckets, no faucet nearby	A row of buckets near a faucet
Weak point	A missed hot day	Building time	Clogged or shifted emitters

Feeding a Bucket Tomato

Daily watering washes nutrients out of a small volume of mix, so bucket tomatoes need regular feeding. Clemson Extension gives two workable routines: a balanced timed-release fertilizer at planting, renewed at the interval on the package, or a water-soluble fertilizer once per week.

Colorado State’s bucket method lists water-soluble fertilizers such as 5-10-5, 8-8-8 and 10-10-10. It starts at half the label rate for the first few waterings, because too much nitrogen gives mealy, flavorless fruit. A mixed gallon of liquid feed covers about two buckets, at roughly half a gallon per plant each time. Fertilizing container plants goes through the label math.

Quick recap

• Grow one tomato per 5-gallon bucket in at least 6 to 8 hours of direct sun, and favor determinate or compact varieties such as ‘Celebrity’ or ‘Bush Early Girl’.
• Drill 3 to 5 drainage holes, fill with soilless mix to about 2 inches below the rim, and bury the stem up to the last two or three sets of leaves.
• Plant after frost danger once the soil is near 60°F, and stake at least 4 feet high the same day.
• By hand, water when the top two inches are dry, which is once or twice a day in summer.
• A reservoir bucket with an overflow hole 2 inches above the bottom, or a drip line on a timer, evens out the moisture between visits.