A self watering planter has a water reservoir in the base and a wick or soil column that draws water up into the potting mix as the plant uses it. An overflow hole stops the reservoir from flooding the roots. They suit moisture-loving houseplants and busy owners, but not plants that need to dry out.
Key Takeaways
- Water rises from a bottom reservoir into the soil by capillary action through a wick or soil column.
- An overflow hole sets the maximum water level and protects the roots.
- Best for plants that like evenly moist soil, such as peace lilies, ferns, and pothos.
- Not ideal for succulents, cacti, snake plants, or orchids.
- Flush the soil from the top now and then to clear fertilizer salts.
How does a self-watering planter work?
Every self-watering planter has the same basic parts: a reservoir at the bottom, a platform or inner pot that holds the potting mix above the water, and a way for water to move upward.
That upward movement is capillary action, the same force that pulls water up a paper towel. University of Illinois Extension describes a common design in which a small soil-filled basket sits in the reservoir and acts as a wick, drawing water into the rest of the soil, with an overflow hole to keep the reservoir from getting too full (Illinois Extension).
University of Maryland Extension describes these containers as a hybrid of hydroponic and conventional container growing, because roots can grow down toward the water while the medium above stays moist (UMD Extension).
The main parts
- Reservoir: holds water below the soil.
- Wick: a cord, fabric strip, or column of soil that touches both the water and the potting mix.
- Fill tube or gap: lets you add water without wetting the soil surface.
- Overflow hole: drains excess so the soil never sits fully submerged.
- Water-level indicator: on many models, a float shows when to refill.
How high can water wick up through the soil?
Capillary rise is limited, which is why most self-watering planters are not very deep. A University of Kentucky guide to wicking containers puts capillary rise at roughly 4 inches above the drain hole in its design (University of Kentucky Extension).
Exact height depends on the potting mix. Fine, peat-based or coir-based mixes wick well, while very chunky mixes wick poorly. For a houseplant, this means roots should be able to reach the moist zone, and the potting mix should be a standard indoor blend rather than a coarse, fast-draining one.
What are the pros of self-watering planters?
- Less frequent watering. The reservoir means you top up less often, which helps if you travel or forget.
- More even moisture. Plants that dislike drying out avoid the swing from soaked to bone dry.
- Less overflow mess. Water goes into the reservoir instead of running out the bottom onto the floor.
- Drier soil surface. The Kentucky guide notes that watering from below keeps the surface drier and reduces evaporation (University of Kentucky Extension), which can also make the top layer less inviting to fungus gnats.
- Built-in overwatering protection. The overflow hole limits how high the water can rise.
What are the cons of self-watering planters?
- Not for every plant. Plants that need to dry out between waterings can stay too wet.
- Salt buildup. Because water mostly enters from below and evaporates from the top, minerals from fertilizer and tap water can accumulate in the upper soil.
- Harder to read. The soil surface may look dry while the root zone is wet, so beginners may add water to the top as well and overdo it.
- Cost. Illinois Extension notes that commercial self-watering containers can be expensive (Illinois Extension).
- Standing water. An old reservoir can grow algae or smell if it is never emptied or cleaned.
Which plants do well in self-watering planters?
| Good fit | Use with caution | Poor fit |
|---|---|---|
| Peace lily | Monstera | Succulents and cacti |
| Ferns | Fiddle leaf fig | Snake plant |
| Pothos | Rubber plant | ZZ plant |
| Spider plant | Philodendron | Orchids in bark |
| Calathea and prayer plant | Herbs on a sunny sill | Plants in very chunky, airy mixes |
"Use with caution" plants can work if you let the reservoir run dry for a few days before refilling, so the soil gets a chance to breathe.
How do you set up a self-watering planter?
- Choose the right mix. Use a standard indoor potting mix that wicks well. Avoid heavy garden soil.
- Thread or seat the wick. Make sure the wick or wicking basket is in contact with both the reservoir and the potting mix.
- Plant at the usual depth. Set the plant at the same depth it grew before, firming the mix gently around the roots.
- Water from the top first. For the first couple of weeks, water from above so the whole root ball is moist and roots grow down toward the wick zone.
- Then fill the reservoir. Once roots are established, switch to filling the reservoir through the fill tube.
- Let it run dry occasionally. Allow the reservoir to empty for a day or two between refills, especially for plants that dislike constant moisture.
- Flush every so often. Every month or two, water heavily from the top so excess drains through the overflow and carries salts with it. Empty the reservoir afterward.
How often do you refill a self-watering planter?
It depends on the plant's size, light, temperature, and the reservoir's capacity. A large, thirsty plant in a bright window may empty a small reservoir within days, while a small plant in lower light may go much longer.
Use the water-level indicator if your planter has one, and check the soil a couple of inches down with a finger. Do not let the soil stay soggy at the top for days on end. For broader guidance on watering rhythms, see our guide on how to choose pots for plants, which covers how pot type changes watering needs.
Are self-watering planters better than pots with drainage holes?
Neither is better in every case. A conventional pot with a drainage hole gives you the most control and suits every plant. A self-watering planter trades some control for convenience and works best with moisture lovers.
Both rely on the same principle: excess water must have a way out. Self-watering planters do it with an overflow hole instead of a bottom drain. If you are weighing options, our article on whether planters need drainage holes explains why that escape route matters.
Browse planters and pots for both styles, and pair a moisture meter or long-spout watering can from our plant care tools to keep tabs on soil moisture. Self-watering planters also work nicely on a plant stand because they rarely drip.
Shop the products in this guide
- Self-Watering Planters Set of 3, 6.5" Round Pots – Each pot has a removable inner pot and a side-fill reservoir.
- Self-Watering Hanging Planter 13.4", Rattan Look 2 Pack – Hanging planters with a reservoir and a water level indicator.
- Self-Watering Window Box Planter, Long Rectangular Pot – A long planter with a reservoir and visible water level.
- 3-in-1 Soil Meter for Plants, Moisture, Light and pH – Check soil moisture to see how the reservoir is keeping up.
Frequently Asked Questions
Can I put an orchid in a self-watering planter?
It is not recommended for moth orchids in bark. Their roots need to dry and breathe between waterings, and bark does not wick water well.
Do self-watering planters cause root rot?
They can if the plant prefers dry soil or the reservoir is never allowed to empty. Choose suitable plants and let the reservoir run dry between refills.
Should I still water from the top?
Water from the top when you first pot the plant and whenever you flush out salts. Otherwise, fill the reservoir.
Can I fertilize a plant in a self-watering planter?
Yes. Use a diluted liquid fertilizer in the reservoir or top watering, and flush periodically to prevent buildup.