Building or repurposing your own large outdoor planters from wood, cement, or found containers is the most reliable way to get oversized garden pots for very little money.
A single large commercial planter can run over a hundred dollars. The good news is that the cheapest routes are often the ones that look the best. The most affordable options for big outdoor planters come from three categories: simple DIY wood boxes, repurposed containers like barrels or troughs, and cement planters. Each route works, but the choice depends on your tools, the look you want, and whether the planter will live in the weather or under a covered porch.
Wood Planter Boxes: The Most Flexible DIY Route
Wood is the most common material for building custom planters at low cost. The key is using inexpensive lumber — fence pickets, common 2x4s, or scrap wood — and keeping the design simple. One reliable build uses dog-ear fence pickets cut to about 30 inches tall, with a 15-inch square plastic nursery pot inserted inside as the actual soil container. The wood surround gets assembled with wood glue and a brad nailer, then sanded and stained or painted before the insert goes in.
Another straightforward design uses 2x4s and 1×6 boards. Cut eight 2x4s into 25-inch lengths, attach them as legs and sides, and add 2×4 feet at the top and bottom for stability. A word of caution: cedar is prone to cracking during fastening, so prefit every piece and drill pilot holes before nailing or screwing. For a 24.5-inch-tall braced version, side pieces and legs get assembled first, then internal bracers are added to hold the plastic pot securely.
Repurposed Containers: The Cheapest Option
The absolute lowest-cost large planters are repurposed containers. Food-grade 50-gallon drums, cattle watering troughs, and even discarded tires can become sturdy planters. The key requirement for every repurposed container is drainage. Without drainage holes drilled in the bottom, water pools and rots the roots. Add gravel at the bottom and fill with a 70% potting soil, 30% compost mix for best results.
Old metal filing cabinets, wicker baskets, and even bicycle baskets mounted on a bike frame work as decorative planters. Thrift stores, garage sales, and local Buy Nothing groups or Freecycle are excellent sources for these containers. Many landscaping companies also give away surplus nursery pots.
Cement Planters: Durable But Heavy
Cement or concrete planters offer modern looks and permanent durability. One approach is to apply microcement over a lightweight form or an existing planter shell. After mixing and brushing on the microcement, let it cure about 12–24 hours, sand while still workable, then seal with a matte sealant if the planter will sit outdoors in the weather. A waterproofing membrane can be applied beforehand for extra protection. The trade-off is weight — cement planters are heavy and difficult to move once placed.
Drainage and Weatherproofing Matter
Every large planter, no matter how cheap to build, will fail without proper drainage. Wood planters also need a waterproof liner or a plastic insert to protect the wood from rot. Without a liner, soil-soaked wood degrades within a couple of seasons. For cement planters left uncovered, the matte sealant is essential to prevent cracking from freeze-thaw cycles. For metal repurposed containers, paint or primer protects against rust. For any repurposed container, confirm the material is not treated with chemicals harmful to plants.
FAQs
What is the cheapest material for a large outdoor planter?
Repurposed containers like food-grade drums, cattle troughs, or old tires are the cheapest option when sourced free from classifieds or thrift stores. Simple fence-picket wood boxes come next at low lumber cost, especially if you already own basic tools like a saw and drill.
How big should a planter be for large plants?
A 15-inch square plastic nursery pot is a common insert size for DIY builds, and it works well for most patio-sized plants.
Do I need to drill drainage holes in every planter?
Yes, every planter that will hold soil needs drainage holes. Without them, water has nowhere to go and root rot kills the plant. This applies to repurposed containers, tires, wood boxes, and even cement planters. If the planter uses a plastic insert with its own holes, the outer container does not need extra holes.
References & Sources
- The Curious Frugal. “30+ Cheap Large Planter Ideas for Your Garden.” Comprehensive list of repurposed and DIY planter options.
- Wicked Handy. “7 Practical DIY Garden Planters You Can Build This Weekend.” Build instructions for wood planters using 2x4s and 1×6 boards.
- The Owner Builder Network. “DIY Tall Planters for Under $20 – An Easy Weekend Project.” Instructions for fence-picket tall planters with plastic insert lining.