Planter boxes sit in an interesting middle ground in the buy-versus-build spectrum. They are simple enough that almost anyone can build them with basic tools, yet the market offers such a wide range of quality and price that buying is sometimes the better choice. The right answer depends heavily on where the planters will live, what they will grow, how many you need, and what aesthetic standard you are working toward.
This guide focuses on box-style planters — the rectangular or square structures used on decks, patios, fence lines, and raised planting areas — rather than pots, hanging baskets, or specialty containers. For a broader look at container gardening, the container gardening for small spaces guide covers container selection, soil, and plant choices across all container types.
What Planter Boxes Actually Need to Do
Before evaluating products or building plans, establish what the planter needs to accomplish. A decorative porch planter holds a few annual flowers in a small soil volume and needs to look good from the street. A vegetable planter on a deck needs adequate depth (minimum 12 inches for most vegetables), proper drainage, soil volume sufficient for root development, and structural integrity to handle the weight of wet soil — 30 to 50 pounds per cubic foot. These are different engineering problems, and cheap decorative planters often fail when pressed into serious vegetable service.
The Drainage Requirement
Every planter box needs drainage holes. This sounds obvious, but many attractive decorative planters are sold without them and intended for use with removable liners. When buying, check drainage hole size and placement. Holes should be at least half an inch in diameter and ideally positioned at the lowest point of the base. When building, drill drainage holes before filling with soil — at least one hole per square foot of base area.
Pre-Made Planter Box Categories
Mass-Market Decorative Planters ($20–$80)
The planters sold at garden centers, discount retailers, and home improvement stores in this price range are primarily decorative. They are made from thin wood, injection-molded plastic, or lightweight composite materials. They look acceptable for a season or two and then begin to warp, crack, or rot. They are fine for annuals or short-term seasonal planting but are not good choices for perennial plantings or serious vegetable growing.
Quality Wood Planters ($80–$300)
Cedar, redwood, and teak planters in this range are genuinely durable. Joinery is better (dadoed or mortised rather than stapled), wood thickness is sufficient (typically three-quarters to one inch), and finishes protect the wood meaningfully. These planters last 8–15 years with reasonable care. They look good on decks and patios and hold up to vegetable growing when sized appropriately.
The limitation is flexibility: you get the dimensions the manufacturer chose, in the wood species they offer, at a fixed price point. If you need a specific size to fit your deck railing, a specific wood to match existing furniture, or a size larger than what is available, buying becomes the wrong path.
Metal and Corten Planters ($100–$500+)
Powder-coated steel, galvanized metal, and Corten weathering steel planters have become popular for their modern aesthetic and exceptional longevity. A well-made metal planter lasts decades with no maintenance beyond occasional cleaning. The tradeoffs are weight (challenging to move once filled), heat transfer in hot climates (metal sides heat the root zone), and cost at the upper end of the range.
DIY Planter Box: What It Takes
A basic cedar planter box is one of the most accessible woodworking projects there is. The skills required are: accurate measuring, straight cutting (a miter box or circular saw with a guide), drilling, and driving screws. Most first-time builders produce a functional planter on the first attempt.
Materials for a Standard 24x12x14-inch Cedar Planter
- Two pieces 1x6 cedar at 24 inches (front and back)
- Two pieces 1x6 cedar at 10.5 inches (sides, accounting for thickness)
- Three pieces 1x4 cedar at 22.5 inches (bottom slats with gaps for drainage)
- Four 1x2 corner cleats or two 2x2 corner posts at 13.5 inches
- 1.5-inch exterior deck screws (approximately 30)
- Total material cost: $18–$35 depending on cedar grade and region
A comparable quality cedar planter in that size range from a garden retailer costs $60–$120. The DIY saving is real, but it assumes about one to two hours of work and that you already own a saw and drill.
Scaling to Multiple Units
Building four identical planters from scratch takes roughly the same setup time as building one, but production time per unit drops by 40–60 percent. If you need six matching planters for a fence line or deck, DIY becomes significantly more economical than buying — and you get exact sizing, exact wood species, and exact finish.
Material Choices and Food Safety
For vegetable planters, material choice matters more than for decorative planters. Cedar and redwood are the safest and most popular choices for food growing. Untreated pine works but degrades faster. Pressure-treated lumber is debated — modern ACQ-treated lumber is considered safe by most extension services, but some gardeners prefer to avoid it in food growing contexts. If using treated lumber, line the interior with food-safe pond liner to create a barrier.
Avoid planters made from pallets unless you can verify the pallet is heat-treated (marked HT) rather than chemically treated (marked MB for methyl bromide). The soil amendments guide goes deeper on soil health in containers, which is especially relevant since planter box soil degrades faster than raised bed soil due to limited volume and more extreme temperature swings.
Decorative Potential: Where DIY Excels
Pre-made planters offer limited customization. DIY planters can be designed to match any architectural style, stained or painted any color, fitted with casters for mobility, built with integrated trellis panels for climbing plants, designed with self-watering reservoirs, or made from reclaimed wood for a specific rustic aesthetic. None of these features are available in most mass-market planters at any price.
For herb gardens in particular — where planters often live on kitchen windowsills, counter tops, or porch railings — custom sizing and a finish that integrates with interior design can matter a lot. The indoor herb garden guide covers container requirements for herbs specifically, which informs what a DIY herb planter needs to include.
When to Buy
- You need a single decorative planter quickly and have no workshop space
- You want a specific material (Corten steel, cast iron, concrete) that requires specialized manufacturing
- You are renting and prefer not to invest building time in something you may not take with you
- The planter will live in a visible location where a professional finish matters
When to Build
- You need a specific size that no commercial product offers
- You want to match existing deck or fence wood exactly
- You need multiple identical planters and want to save cost per unit
- You want to add features like casters, built-in irrigation, or integrated trellising
- You are growing food and want to control material choices completely
Frequently Asked Questions
What wood is best for DIY planter boxes?
Cedar is the top choice for most gardeners: naturally rot-resistant, easy to work with, widely available, and appropriate for food growing. Redwood is equivalent or slightly better but harder to find and more expensive. For non-food planters, pine or fir with a good exterior finish works and is cheaper.
How deep should a vegetable planter box be?
Minimum 10 inches for shallow-rooted crops like lettuce and herbs. Twelve to fourteen inches for most vegetables including tomatoes, peppers, beans, and squash. Sixteen to eighteen inches for root vegetables like carrots and beets. Deeper is always better if weight and materials allow.
How do I prevent a wooden planter from rotting?
Use naturally rot-resistant wood (cedar or redwood), pre-drill all screw holes to prevent splitting, use stainless or hot-dipped galvanized hardware, leave a gap between the planter bottom and any surface it sits on, and ensure adequate drainage so water does not pool inside.
Are self-watering planter inserts worth it?
Yes for planters that will be in hot, sunny locations or used for plants with consistent water needs like tomatoes and herbs. The reservoir extends time between watering and reduces drought stress. They add $15–$40 to DIY material cost or $30–$80 to a purchased planter upgrade.
Can I build a planter box without a saw?
Yes. Most hardware stores will make straight crosscuts for a small fee (typically $0.25–$1.00 per cut). Bring your cut list, have them cut the lumber, and assemble at home with only a drill. This approach works well for beginners who do not own a saw.