A plastic kiddie pool that has outlived its splash days makes an unlikely but practical garden planter. The project takes about an hour, needs beginner-level skills, and costs $30 to $40 if you buy fresh potting mix. Any rigid, non-inflatable pool works, and the bigger the pool, the more plants it holds. Repurposing household castoffs into planters is a proven DIY pattern; turning an old filing cabinet into a patio flower planter follows the same save-it-from-the-landfill logic.
You can plant anything with shallow roots, which includes most herbs, many vegetables, and plenty of annual flowers. A pool planter sits low, holds heat, and dries out faster than a ground bed, so the location and the watering routine matter as much as the planting itself.
The total cost stays low because the pool is already in hand. A bag of potting mix, a drill bit, and a handful of transplants are the only purchases, and the planter can be emptied and moved at the end of the season if the layout changes.
Choose the Right Pool and Find Its Spot
Rigid plastic pools work well; inflatable versions puncture too easily and offer no support for wet soil. Size matters less than location, because a pool filled with damp soil and plants gets heavy fast. Park it where it will stay before you add soil. A large patio, gravel area, or bare dirt patch works best, and the pool should sit off the lawn unless you accept that the grass underneath will die. Keep the pool off wood decking, since moisture trapped underneath can damage the deck boards over a season. If you want a permanent bed with more depth, a tall tapered planter made from two boards gives roots more room than a shallow pool.
Why Rigid Beats Inflatable
Rigid plastic holds its shape under saturated soil, resists punctures from shovels, and survives a full season of sun. Inflatable rings flex, leak at seams, and make drainage holes impossible to seal. Check the pool for cracks before committing; a slow leak that is harmless for splash play becomes a soggy mess when it holds soil.
Sun Exposure and Soil Temperature
Raised planters and shallow containers heat up faster than ground beds because sun strikes the side walls. In hot climates, position the pool where it gets morning sun and afternoon shade, and expect to water more often than you would a buried bed. Dark plastic absorbs heat, which can push root-zone temperatures past what cool-season crops tolerate. Lighter colored pools stay cooler than dark ones, so the original pool color matters more than most people expect: a white or pale blue pool reflects heat, while a black pool turns into a solar collector.
Drill Drainage and Prep the Pool
Drainage decides whether the planter thrives or drowns. A pool with no holes turns into a swimming pool for roots after rain. Drill a ring of holes across the bottom, spaced about 4 to 6 inches apart, then raise the pool an inch or two off the ground so water can escape. Adding a layer of landscape fabric over the holes keeps soil from washing through while water still drains. A garden that doubles as a restorative space starts with simple, well-made elements; the case for converting a normal garden into a wellness garden explains why container projects like this one earn their keep.
The Hole Pattern That Works
- Flip the empty pool upside down on a flat surface
- Mark a grid of 8 to 12 holes, 4 to 6 inches apart
- Drill each hole with a 1/2-inch bit, angling slightly outward
- Flip the pool right side up and rinse out the plastic shavings
Holes along the side walls, an inch above the bottom, act as overflow vents and keep the soil surface from flooding during heavy rain.
Lifting and Leveling
Set the pool on bricks, pavers, or scrap lumber so water drains freely. Check the level in both directions; a tilted pool collects water at one end and leaves the other end dry. Two or three lifting points are enough to keep the bottom off the soil and allow air movement underneath. Leaving a gap under the pool also stops ants and slugs from colonizing the damp shadow and keeps the bottom plastic from rotting against wet ground.
Fill With Soil and Pick Shallow-Rooted Plants
Fill the pool with potting mix rather than garden soil. Garden soil compacts in containers, drains poorly, and brings weed seeds and pathogens along. Potting mix stays loose, holds moisture evenly, and gives young roots room to spread. Most herbs, many vegetables, and lots of annual flowers grow fine in the 8 to 12 inches of depth a pool provides. For a structured herb garden, a DIY hexagon herb planter with a double tier offers a similar planting area with more vertical interest.
Best Plants for a Shallow Planter
| Plant group | Root depth | Examples |
|---|---|---|
| Herbs | 4 to 6 in | Basil, thyme, parsley, cilantro |
| Leafy greens | 4 to 8 in | Lettuce, spinach, arugula |
| Root vegetables | 6 to 10 in | Radish, carrot, beet |
| Annual flowers | 6 to 10 in | Marigold, petunia, zinnia |
Avoid deep-rooted crops such as tomatoes, squash, and potatoes; they outgrow the pool quickly and struggle with restricted roots. Succession planting extends the harvest: pull spent lettuce in early summer and replace it with a warm-season crop like bush beans or heat-tolerant herbs.
How Deep Is Deep Enough
Most herbs stay happy in 6 inches of mix. Leafy greens and root vegetables prefer a bit more. Measure the pool’s wall height before filling, and top off with mix so the root zone matches the plants you chose.
Planting in Rows or Clusters
Sow seeds or set transplants in staggered rows so each plant gets airflow. Water the mix before planting, settle the roots, and firm the soil gently. Interplant quick crops like radishes between slower ones like carrots to use the whole season. Keep the tallest plants on the north side of the pool so they do not shade shorter neighbors, and thin seedlings once they have two true leaves.
Water and Feed a Shallow Container
Containers dry out faster than ground beds because more root zone is exposed to sun and wind. Check moisture daily, push a finger an inch into the soil, and water when the top feels dry. A mulch layer of straw or shredded bark slows evaporation and keeps soil temperature steadier. Clear bottles and glassware find their way into gardens too; creative ways to repurpose glass bottles into home and garden features show how leftover household items can earn a second life alongside the pool planter.
Watering Schedule That Works
- Water deeply until it runs from the drainage holes
- Check twice a day during heat waves
- Group the pool with other containers to share shade
- Use a watering can with a rose head to avoid washing seeds out
An inch of water per week is a starting point, but sun exposure and plant size move the number up or down. During heat waves, a shallow pool may need water twice a day. Check the ground below the pool too; water pooling under the drainage holes means the mix is saturated and the watering interval is too short.
Feeding and Refreshing the Soil
Shallow soil holds fewer nutrients than a ground bed, so feed every 3 to 4 weeks with a balanced liquid fertilizer at half strength. At season end, dump the spent mix into the compost pile or a bed, and start fresh next year. Mixing in finished compost keeps the soil alive; vermicomposting turns kitchen waste into nutrient-rich garden soil that feeds a container garden all season. A monthly top-dressing of compost or a slow-release granular feed labeled for containers keeps the pool productive without guesswork.
Extend the Life of the Pool Planter
Plastic pools break down in sunlight, so plan for a two- or three-year lifespan. At the end of the season, pull the plants, dump the soil, and rinse the pool. Store it upside down in a shed or garage, off the ground, so water cannot pool in the bottom and freeze. A pool left outside through winter fills with ice, and the expansion cracks the plastic, so bring it inside or tip it upside down so rain cannot collect.
End-of-Season Cleanup Checklist
- Remove plants and shake roots free of soil
- Dump spent mix into compost or a garden bed
- Scrub the pool with soapy water and rinse
- Dry it fully and store upside down indoors
Upgrading When the Pool Wears Out
A worn pool planter is a sign to scale up, not give up. The filing cabinet planter, the two-board tapered planter, and the hexagon herb bed all reuse the same skills with more permanent materials. When the pool finally retires, a convertible garden bench that transforms into a picnic table gives the yard a second useful feature built with the same beginner-friendly approach.