Build a Deck-Top Pond: Weekend DIY Aquatic Haven

If you can hammer a few boards together, you can build a charming deck-top pond in one weekend. Here's how.

What You Need

• Two 8-foot lengths of 1x8 cedar (or 1x10/1x12 for deeper pond)
• Waterproof polyurethane glue
• Table saw or circular saw with guide
• Stainless-steel siding nails, galvanized 6d finishing nails, or deck screws
• Plastic liner or rubberized paint-on sealant (e.g., Elasto-Seal)
• Ruler, pencil

Instructions

Step 1: Gather materials. Cedar is rot-resistant and ages gracefully. Cut 30-inch side panels, 15-inch end panels, and glue a 15 x 28¼-inch floorboard. Use waterproof polyurethane glue for all wood joints.

Steps 2–6: Glue and nail one side panel to floorboard with ⅞-inch overhang for ends. Attach remaining ends and side. Cut a 15-inch divider for a planting bed, glue and nail in place. Mark guidelines with ruler.

Step 7: Cut four 1x2 cedar corner cleats, coat with glue, and nail inside corners for strength and sealing.

Step 8: Line interior with plastic liner or apply rubberized sealant (safe for fish if adding). Coat both water and garden sections; add an extra coat. Drill 2–3 drainage holes in garden side base. Elevate box on bricks.

Step 9: Choose miniature plants varying in form, texture, color, and size. Combine submerged, marginal, and edge plants. Fill garden section with soil; select plants with similar light/water needs.

Choosing Miniature Plants

Miniature water lilies (need only 1½ feet spread) are perfect. Here are plant categories for a small water garden:

Submerged Plants (Oxygenators)

• Water hawthorn (Aponogeton distachyos)
• Water fern (Ceratopteris pteridioides)
• Water hyacinth (Eichhornia crassipes)
• Duckweed (Lemna minor)
• Indian pond lily (Nuphar polysepala)
• Miniature water lily (Nymphaea x helvola)
• Water snowflake (Nymphoides indica 'Variegata')
• Water fringe (Nymphoides peltata)
• Water lettuce (Pistia stratiotes)

Marginal Plants

• Japanese sweet flag (Acorus gramineus 'Ogon')
• Southern swamp lily (Crinum americanum)
• Dwarf papyrus (Cyperus haspans)
• Chameleon plant (Houttuynia cordata 'Chameleon')
• Water pennywort (Hydrocotyle ranunculoides)
• Four-leaf water clover (Marsilea mutica)
• Parrot feather (Myriophyllum aquaticum)
• Arrowhead (Sagittaria latifolia)
• Dwarf cattail (Typha minima)

Edge Plants

• Deer fern (Blechnum spicant)
• Maranta (Maranta bicolor)
• Watercress (Nasturtium officinale)
• Houseleek (Sempervivum tectorum)
• Blue-eyed grass (Sisyrinchium angustifolium)

Deck-Top Pond Maintenance

Not a permanent structure. In fall, empty, dry, and store in a shed. In temperate zones, overwinter in garage or leave out. Move fish indoors if freezing.

1. Layer pot bottoms with pea gravel or plastic mulch to contain soil.
2. Use heavy topsoil (not potting soil) mixed with slow-release fertilizer.
3. Plant root balls, fan roots, cover crowns with 1 inch soil, tamp firmly, top with pea gravel.