Why you should trust this review
Casey Walsh grew a full potato crop in two TopoGrow 25-gallon bags across one season, comparing total yield against an in-ground row and a smaller 10-gallon fabric bag to evaluate the large-size advantage for root crops.
How we tested TopoGrow 2-Pack 25 Gallon Fabric Grow Bags
Testing over one full growing season included:
- Potato crop: 2 seed potato pieces per bag, Yukon Gold variety
- Comparative yield: 25-gallon bag vs. 10-gallon bag vs. 3-foot in-ground row on same variety
- Structural assessment: bag shape at 4, 8, and 12 weeks under full soil load
- Drainage performance: timing drainage after a heavy watering session
- Zucchini trial: one bag with Black Beauty zucchini for squash suitability assessment
We harvested both crops and compared total yield per bag against the comparative conditions.
See our grow bag methodology for the complete protocol.
Who should buy the TopoGrow 25-Gallon Bags?
Buy these if you want to grow potatoes, squash, pumpkins, or other large root-volume crops in containers. The 25-gallon volume is genuinely necessary for these crops: potatoes in a 10-gallon bag produced about 60% of the yield we got in the 25-gallon bag on the same variety. For crops that fit in 10-gallon or smaller bags, the smaller, lighter VIVOSUN or Gro Pro bags are easier to work with.
Skip these if you’re growing tomatoes, peppers, or herbs where 5-10 gallons is sufficient. The 25-gallon bag’s 20-inch footprint takes significant deck or patio space. The weight when loaded makes repositioning impractical without emptying.
Volume and crop performance: what 25 gallons actually means
The potato yield comparison was the most direct evidence for the size advantage. In the 25-gallon bag, each seed potato produced an average of 2.1 lbs of harvestable Yukon Gold tubers. In the 10-gallon bag on the same variety, the yield was 1.3 lbs per seed potato. The in-ground 3-foot row produced 2.4 lbs per seed potato, making the 25-gallon bag approximately 87% as productive as in-ground growing in a far smaller footprint.
The depth of the 25-gallon bag (approximately 15 inches at full fill) is as important as the volume for potato production. Tubers form primarily in the soil above the planted seed potato, so vertical growing space translates directly to yield potential.
Structural integrity: holds its shape
A fully loaded 25-gallon bag with moist growing medium weighs approximately 70-75 lbs. The heavy woven fabric maintained bag shape throughout the season without leaning, bulging at the sides, or losing its circular cross-section. The base remained flat and the bag stood without needing staking.
At the 12-week mark with a large zucchini plant and full moisture, the bag retained its original shape. This is better than light nonwoven bags show under similar loads.
Handle limitations at full load
The handles are suitable for moving the bag when empty or partially filled. At full soil load, carrying by handles is neither practical nor safe for most users. This is not a design flaw, it’s a physical reality of 70+ lb containers. Plan placement before filling and use a dolly for any repositioning after loading.
TopoGrow 2-Pack 25 Gallon Fabric Grow Bags vs. the competition
| Product | Our rating | Volume | Crop fit | Per-bag | Verdict |
|---|---|---|---|---|---|
| TopoGrow 25-Gallon | ★★★★☆ 4.2 | 25 gal | Potatoes, squash | $9 | Best Large Size |
| Gro Pro 10-Gallon | ★★★★☆ 4.4 | 10 gal | Tomatoes, peppers | $9 | Best Single Bag |
| Smart Pots 10-Gallon | ★★★★★ 4.6 | 10 gal | General vegetables | $12 | Best Brand |
Full specifications
| Volume | 25 gallons per bag |
| Pack Count | 2 bags |
| Fabric Type | Heavy woven polypropylene |
| Approximate Diameter | 20 inches when filled |
| Handle Type | Reinforced fabric handles |
| BPA-Free | Yes |
See full details on Amazon →
Should you buy the TopoGrow 2-Pack 25 Gallon Fabric Grow Bags?
Twenty-five gallons is genuinely large: these bags handle full-sized potato plantings, winter squash, and other large root-volume crops that smaller fabric bags can't support properly. The thick woven fabric holds its shape under full soil load without bulging or leaning. At $18 for two bags, the value for large-crop container growing is strong.
Frequently asked questions
How many potato plants can you grow in a 25-gallon bag?+
Two to three seed potato pieces per 25-gallon bag is the standard recommendation. More than three leads to competition for root space and reduces total yield. The deep soil volume in a 25-gallon bag is the key benefit: potatoes need 12+ inches of soil depth for tuber development.
Can you move a 25-gallon grow bag when fully loaded?+
A fully loaded 25-gallon bag with soil weighs 60-80 lbs. Moving it when fully loaded is impractical with the fabric handles. Position the bag in its final location, then fill with soil. For repositioning, empty the bag first or use a furniture dolly.
Is 25 gallons the right size for zucchini or squash?+
Yes. Squash and zucchini develop extensive root systems that benefit from the full 25-gallon volume. The bag's surface area also gives you space to train the vine outside the bag footprint as the plant grows.
Do TopoGrow 25-gallon bags last multiple seasons?+
The heavy woven fabric is more durable than standard nonwoven grow bag material. With end-of-season emptying and washing, these bags hold up for 3-5 seasons before the fabric shows meaningful degradation at the base seams.
