Pots & Containers

Fabric pots vs plastic, and what size to use

Why fabric pots make overwatering hard, why a bigger pot is often worse, the finish sizes for each tent, and how to water by weight instead of guesswork.

Pots are the part of the kit people put the least thought into and then blame for the most problems. Overwatering, root-bound plants that stall, a tent that's always too humid — a surprising amount of that traces back to the container. Here's what actually matters.

Fabric vs plastic

Fabric potPlastic pot
RootsAir-pruned at the wall — dense, fibrousCircle the wall — can get root-bound
Overwatering riskLow; drains and breathes from all sidesHigh; only drains from the bottom
Drying speedFast — water more oftenSlow — water less often
Humidity in the tentHigher (evaporation through the walls)Lower
HandlingFloppy when empty, hard to move when fullRigid, easy to lift and rotate
ReuseWash and reuse a few seasonsIndefinitely
CostLowLow

For an indoor tent, fabric wins for beginners because the thing most likely to kill a first plant is too much water, and a fabric pot makes that genuinely difficult. The trade-off is that it dries faster and pushes humidity up — which is exactly what your exhaust fan is for.

Plastic makes sense if you're away for days at a time, if the tent already runs humid, or if you want to lift and rotate plants often.

Sizing: bigger isn't better

A plant only uses the water in the volume its roots have reached. Put a seedling in a 7-gallon pot and the outer soil stays wet for weeks, goes stale, and the roots that reach it sulk. The result looks like overwatering — because it is.

Rules that work:

  • Seedlings and cuttings: start in a 1-gallon pot (or a solo cup), and move up when roots show at the drainage holes or fabric wall.
  • Finish size depends on how big you'll let the plant get and how long it grows:
PlantFinish potNotes
Herbs, salad, compact plants1–2 gallonCan stay in this all season
One plant in a 2×23 gallon5 if you're growing it big
Two plants in a 2×43–5 gallon each5 gives more forgiving watering
Four plants in a 4×45 gallon each7 if the grow runs long
Big single plant, long grow7–10 gallonOnly with a tall tent

Transplanting up two sizes at a time (1 → 3 → 5) is fine. Going straight from a cup to 5 gallons is where the stale-soil problem starts.

Reading the pot

The easiest watering rule with fabric pots is weight. Water thoroughly once, lift the pot and remember how heavy it is. Then lift it every day; when it feels about half that weight, water again. A pot that still feels heavy doesn't need water no matter what the surface looks like.

With plastic, add a second check: a finger two inches into the mix. Dry at that depth means water; damp means wait. Plastic pots stay wet at the bottom long after the top dries out.

Drainage and trays

Every pot needs somewhere for water to go. Fabric drains through its whole surface, so a saucer or tray under each pot catches the runoff — and you want 10–20% runoff each watering to flush old salts out. Empty the trays afterward; a pot standing in its own runoff is a plastic pot again.

A tent's floor tray is a backstop, not a saucer. Don't let water pool in it.

Medium, briefly

The pot and the medium are a pair:

  • Potting soil (a quality bagged mix, not garden soil) holds nutrients and water. Forgiving, slower, less feeding. Pair with any pot.
  • Coco coir with 20–30% perlite holds water but no nutrients, so you feed at every watering. Faster growth, more control, less forgiving. Pairs very well with fabric pots, since coco likes to be watered often and fabric dries fast.

Avoid "moisture-retaining" or "water-saving" mixes indoors — they're built for patios in summer and stay wet far too long in a tent.

Pots & Containers

What to buy

  • 3-gallon fabric pots for a 2×2 or a first grow — a pack of five is a few dollars and lasts seasons.
  • 5-gallon fabric for a 2×4 or 4×4.
  • Saucers to match, or a set of shallow plant trays.
  • 1-gallon pots or cups to start in.
  • A bag of good potting mix or a coco/perlite blend, depending on how hands-on you want feeding to be.

Fabric, sized to the plant not the tent, watered by weight, standing on a saucer you actually empty. That's most of what separates a plant that thrives from one that just survives.

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