How many potatoes do you get from one grow bag?

Expect 2 to 3 pounds of tubers per seed potato under decent conditions, so a 10-gallon bag with two seed pieces typically returns 4 to 6 pounds and a 20-gallon bag with four returns 8 to 12. Early varieties sit at the lower end because they finish sooner; maincrop varieties given a full season and steady water sit at the upper end. Yields collapse well below that range if the bag dries out during tuber formation, which is the three to four weeks after flowering.

Can you plant a whole potato in a grow bag?

Yes, and for small seed potatoes under about 2 ounces you should — cutting them leaves too little stored energy per piece. Larger seed potatoes are cut into pieces of roughly 1.5 to 2 ounces with at least two eyes each, then left to cure for 2 to 3 days in a warm, airy spot so the cut surface suberizes. Planting a fresh-cut wet piece into moist mix is the usual cause of seed rot.

Do potatoes need a deep grow bag?

They need about 14 to 16 inches of usable depth, which in practice means a 10-gallon bag or larger. Depth matters because tubers form on stolons off the buried stem, above the seed piece, not below it — so the yield depends on how much stem you can cover as the plant grows. Start with 4 to 6 inches of mix, plant into that, and add more as the shoots rise. A shallow bag simply gives the plant nowhere to make tubers.

Should you cut seed potatoes or plant them whole in bags?

Cut them if they are bigger than a hen egg, plant them whole if smaller. Each piece needs at least two eyes and roughly 1.5 to 2 ounces of flesh to fuel the first shoots. Use a clean knife, cure the pieces cut-side up for a couple of days, and never plant supermarket potatoes — most are treated with sprout inhibitor and can carry disease. Buy certified seed potatoes, which extension services recommend specifically to keep late blight and scab out of home gardens.

Can you plant potatoes and other crops in the same bag?

It is not worth it. Potatoes are heavy feeders with a dense, spreading root and stolon system that fills the bag, and the repeated hilling that drives yield buries anything planted alongside them. Companion planting works in open ground where there is lateral room; inside a 15-gallon bag there is not. Give potatoes their own bags and grow the herbs and greens separately.

How Many Potatoes Per Grow Bag? Seed Pieces by Bag Size

Written & researched by Elena Marsh Gardening & Landscaping Editor

Updated October 2026

Low-angle view of a person's hands pressing seedlings into dark soil in a timber raised bed, in soft early-morning light

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Plant one seed potato per 5 gallons of bag volume: one in a 5-gallon bag, two in a 10-gallon, three in a 15-gallon and four in a 20-gallon. That works out to roughly 6 to 8 inches between seed pieces, matching the in-row spacing extension services give for open-ground potatoes. Crowding beyond that does not increase total yield — it converts the same harvest into more, smaller tubers and drives the bag into drought stress during tuber bulking. Expect about 2 to 3 pounds of potatoes per seed piece planted.

How many per bag size?

Bag volumes are approximate between brands, so cross-check the stated diameter. These figures assume a fabric bag filled to within a couple of inches of the rim by the end of hilling.

Bag size	Typical diameter	Seed pieces	Expected yield
5 gal	12 in	1	2–3 lb
7 gal	14 in	1–2	3–5 lb
10 gal	16 in	2	4–6 lb
15 gal	18 in	3	6–9 lb
20 gal	20 in	4	8–12 lb
30 gal	24 in	5–6	10–18 lb

Golden-hour view of a person's hands pressing seedlings into dark soil in a timber raised bed

Why not just plant more per bag?

Because potato yield in a container is limited by water and root volume long before it is limited by the number of stems. Two seed pieces in a 10-gallon bag already push a mature canopy that transpires heavily; four in the same bag double the demand on an unchanged water reserve, and the bag hits wilting point every hot afternoon. Tuber bulking — the three to four weeks after flowering when the crop actually forms — is the stage most sensitive to inconsistent moisture, and it is also when a crowded bag is least able to keep up. The result is a heap of marble-sized potatoes rather than a bigger harvest.

Wide environmental view of a person's hands pressing seedlings into dark soil in a timber raised bed, in warm late-afternoon light

How do you fill and hill the bag?

This is where container potatoes are won or lost, because tubers form on stolons off the buried portion of the stem, above the seed piece. More buried stem means more places to make tubers.

Roll the bag down and put 4 to 6 inches of moist potting mix in the bottom.
Set the seed pieces cut-side down, eyes up, evenly spaced. Cover with 3 inches of mix.
When shoots reach 6 to 8 inches, add mix to bury the lower half of the stems, unrolling the bag as you go.
Repeat every 2 to 3 weeks until the mix is 2 inches below the rim, usually three or four rounds total.
Stop hilling once the plants flower, and keep the moisture steady from then until the foliage yellows.

Any tuber that pushes to the surface and sees light turns green and develops solanine. The USDA and extension food-safety guidance is straightforward: cut away green portions, and discard tubers that are green throughout. Keeping them covered is easier than sorting them later.

Three-quarter view of a person's hands pressing seedlings into dark soil in a timber raised bed, in soft early-morning light

When do you plant and harvest?

Plant two to four weeks before your last spring frost date, or once the mix holds around 45 to 50 F. Bags have an advantage here — the mix warms faster than open ground and you can move a bag under cover if a late freeze threatens. Early varieties are ready roughly 70 to 90 days after planting, maincrop varieties 100 to 130. For new potatoes, dig in gently two to three weeks after flowering; for storage potatoes, wait until the foliage has died back, then stop watering for 10 to 14 days so the skins set before you tip the bag out.

The bottom line

One seed piece per 5 gallons, cut to 1.5 to 2 ounces with two eyes each, cured for two days, hilled three or four times, and watered without interruption through bulking. That combination reliably returns 2 to 3 pounds per piece. For the method end to end see can you grow potatoes in a grow bag, and for the mix see what to fill grow bags with. Our best grow bags roundup covers which bags hold up to repeated filling and tipping.

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How Many Potatoes Per Grow Bag?