Choose Size

Decide on the size of your triangular planter and write down the measurements.

Step 1

Cut Lumber

Cut three pieces of 4x4 pressure-treated lumber the same length. Using a miter saw, cut each end at a 60-degree angle. The angles should face each other and fit together to make a triangle.

Step 2



Add Layers

Repeat Step 2, adding additional layers to the height of the triangle. Three to five layers work well.

Step 3



Drill to Secure

Drill holes through the layers of pressure-treated lumber and hammer in large nails to secure the form.

Step 4

Line Planter Box With Landscape Fabric

When the planter is secure, line the sides with landscaping fabric and staple the fabric into place. This protects the lumber from weeds and moisture.

Step 5

Fill With Soil

Fill the planter with soil.

Step 6

Plant Your Plantings

Add greenery of your choice using normal planting methods.