A rain barrel with planter combines roof runoff collection with a planted top, and building one takes about an afternoon.
Making a rain barrel with a planter on top is a weekend project that turns roof runoff into free water for your garden while giving you extra planting space. The build has two parts: a working rain barrel that collects water safely, and a planted section that sits on top. Below is the complete process, from cutting the barrel to winterizing it.
What You Need Before You Start
The build starts with the right barrel. Use a food-grade barrel — never one that held chemicals, oil, or soap. A 55-gallon barrel is the standard size for rain collection, but the planter-style build in this guide uses a barrel 22 inches in diameter and 38 inches high, cut in half so one part holds water and the other holds plants.
For the water section, you will need a spigot, Teflon tape, a 2-inch overflow fitting, PVC piping, and a screened inlet. For the planter section, gather weather-resistant outdoor deck screws — not drywall screws, which rust — plus drainage holes, gravel, soil, and your plants.
Building the Rain Barrel Body
Set the barrel on a stable, level base before you do anything else. Raising the barrel on blocks or wood also lets you fit a watering can under the spigot.
Install the spigot low on the barrel so the water drains by gravity. Then add the overflow outlet near the top — a 2-inch fitting with PVC piping that routes excess water away from your foundation, house, and walkways.
Cut the downspout to fit your barrel inlet or a diverter, following the manufacturer’s instructions. Cover the opening with a screen or a lid to keep out debris and mosquitoes. Position the barrel so roof runoff flows directly into it.
Adding the Planter Top
The planter section uses the other half of the barrel. Drill drainage holes in the bottom, add a layer of gravel, then fill with soil and plant. Set it securely on top of the barrel body — it needs to sit flat so it doesn’t tip, and the drainage holes let excess water pass into the barrel below.
Outdoor deck screws are the right choice for any joining or reinforcing here; they hold up to weather and exposure in a way drywall screws will not.
Watering Safety and Barrel Maintenance
Rain barrel water is non-potable — never drink it. For ornamental plants, University of Minnesota Extension says collected rainwater is best applied by hand, drip irrigation, or soaker hose rather than overhead sprinklers. If you are using the water on edible plants, Rutgers advises applying it to the soil and avoiding the edible parts of the plant entirely.
Do not collect runoff from roofs treated with moss killers or zinc strips, and keep the barrel disconnected and drained before freezing weather. Repeated freezing and thawing can crack or weaken the plastic. Regular upkeep is simple: keep screens clean and covered, check that the overflow works during heavy rain, and make sure the barrel stays on a level base.
| Build Step | Key Detail | Why It Matters |
|---|---|---|
| Barrel selection | Food-grade; 55-gallon standard | Prevents chemical contamination |
| Spigot install | 3/4-inch hole, Teflon tape | Sealed gravity drain |
| Overflow outlet | 2-inch fitting with PVC | Keeps water away from foundation |
| Base setup | Concrete blocks, sloped | Stability and spigot access |
| Planter top | Drainage holes, gravel, soil | Healthy plants, water flow |
| Screened inlet | Cover all openings | Blocks debris and mosquitoes |
| Winter prep | Drain and disconnect | Prevents freeze cracks |
If you would rather buy a ready-made unit than build one, our tested roundup of the best rain barrel with planter options covers the top commercial picks and what each one does well.
The whole project takes a few hours with basic tools. The payoff is free water for your garden, fewer storm runoff issues around your foundation, and extra planting space — all from one barrel. For the best results, use a food-grade barrel, keep every opening screened, and never let it sit full through a hard freeze.
FAQs
Can I use rain barrel water on vegetable gardens?
Yes, but with care. Apply the water directly to the soil, not to the edible parts of the plant.
How do I keep mosquitoes out of a rain barrel?
Cover every opening with a fine screen or a fitted lid. The screen should sit over the inlet where the downspout empties and over any overflow opening. Keeping screens clean and properly seated is the most effective way to stop mosquitoes from breeding in standing water.
Do I need to take my rain barrel down in the winter?
Yes, drain it and disconnect it before freezing weather arrives. Water expands as it freezes, and repeated freeze-thaw cycles can crack or weaken the barrel. Once drained, store it upside down or covered to keep debris and water out until spring.
References & Sources
- EPA. “How Can I Make a” (Rain Barrel DIY Instructions). Covers spigot, overflow, and base setup steps.
- University of Minnesota Extension. “Rain barrels.” Details safe watering methods for collected rainwater.
- Rutgers NJAES. “Rain Barrel Water Quality Testing.” Addresses using collected water on edible plants.