QUICK ANSWER
Yes — and it doesn’t matter much whether that extra soil comes from hilling in the ground or filling a grow bag. Both work through the same mechanism: many potato varieties keep forming new tubers along whatever stem ends up buried, so progressively adding soil as the plant grows gives it more room to produce. The one approach that reliably limits your harvest is skipping this step entirely and leaving the soil level alone all season.
Why Adding Soil Beats Adding None
Potato plants don’t just form tubers around the original seed potato — many varieties continue producing new tubers along the portion of stem that ends up buried as the plant grows. More buried stem genuinely means more surface area for tubers to develop along. Leave the soil level untouched all season, and the plant only has the shallow area right around the original planting depth to work with, which caps how much it can produce regardless of how well you otherwise care for it. It also leaves developing tubers closer to the surface, raising the risk of sun exposure turning them green.
Two Good Options, Same Underlying Principle
Hilling in the ground means mounding loose soil up around the base of the stem as the plant grows, typically starting once it reaches 6-8 inches tall and repeating every couple of weeks. Each round buries a bit more stem, extending the zone where new tubers can form.
Grow bags work through the identical mechanism, just contained in fabric instead of open ground: start with the bag partly filled, and add more growing medium as the stem grows taller, unrolling the sides as needed until the bag is full. You’re doing the same progressive burying, just in a portable container.
Since both methods rely on the same underlying biology, the real choice between them comes down to convenience and growing conditions — not which one inherently produces more. Bags make sense for poor native soil, tight spaces, or easier harvest; open-ground hilling makes sense if you already have decent garden soil and don’t mind the extra digging at harvest time.
How to Get the Best Results With Either Method
• Start once the stem reaches 6-8 inches tall — this applies whether you’re hilling in the ground or filling a bag.
• Cover roughly the lower two-thirds of visible stem each round, leaving the top growth and leaves exposed to keep photosynthesizing.
• Repeat every 2-3 weeks as the plant continues growing, rather than doing it once and stopping.
• Water grow bags more often than in-ground plantings — fabric bags dry out faster since moisture escapes through the sides, not just the top.
• Don’t wait too long between rounds. Tubers that get partially exposed before you catch up on hilling can still green in the meantime.
Related Questions
Does this apply to every potato variety?
Mostly, but the benefit is bigger for varieties that keep producing tubers along the stem as they grow. Some varieties set tubers at a more fixed depth regardless of extra soil — for those, hilling or bag-filling still helps prevent greening, just with less of a yield boost attached.
Is one method actually better than the other?
Real comparisons are mixed, and neither reliably wins on yield alone. Choose based on your situation — bags for poor soil, tight space, or easier harvest; open ground if you already have good soil and enough room.
What if I forgot to hill until the plant was already tall?
Start now rather than skipping it — you’ll still get some benefit from whatever stem you’re able to bury at this point, even if it’s later than ideal. Check for any already-exposed, greening tubers while you’re at it.
Sourced from: NDSU Extension, PreparednessMama, GrowVeg
