How to Build an Octagonal Framed Flower Bed

Choose the site for your flower bed and note its growing conditions. Most flowers need full sun to thrive during the growing season. Amaryllis, impatiens and begonias are a few examples of flowers that grow well in partial sun. If the soil has too much clay or sand, mixing compost, top soil or fertilizer into the soil add oxygen, good bacteria and nutrients.

Create a design plan for an octagonal flower bed. If you plan to add a central focal point, like a birdbath, consider arranging the plants so they increase in height from the outside in, without exceeding the height of the birdbath. Consider choosing plants that will blossom at different times so the flower garden looks fresh throughout the growing season. For instance, coneflowers are a hardy perennial that grows well in USDA zones 3 through 8 and produce flowers from later spring until the first frost. Verbena is a perennial that grows well in zones 6 through 10, develops flowers in early spring and attracts butterflies.

Use a tape measure and eight wooden stakes to mark the eight corners of the octagon in the ground. Each wooden stake should be an equal distance apart from the stakes on either side of it. For instance, the eight points of a small octagonal flower bed may measure 2 feet apart. Tie a length of string around the wooden stakes to create a clear outline of the flower bed.

Use a second set of eight wooden stakes to mark the outer corners of the flower bed frame. The frame will be as wide as your material. Figure 6 inches of width if you are using landscaping timbers, as timbers measure 6 by 6 inches. Measure the stones, bricks or pavers if you plan to lay them as your frame. Use flour or landscaping paint to draw straight lines connecting the outer stakes.

Clear the site where the flower bed and frame will be, removing grass, debris, rocks and root systems. Continue to dig a 4-inch trench along the outline of the frame.

Use a hoe to spread a 2-inch layer of sand over the octagonal trench. Press the bricks into the sand 1/4-inch apart. Tap them with a rubber mallet and use a level to ensure they are even. When the trench is filled, pack sand between the gaps and brush off any excess. Moisten the sand so it hardens to the bricks when it dries, keeping them firmly in place.

Mix a 2-inch layer of top soil into the flower bed soil to add the nutrients and oxygen many flowers need to thrive. Add a 1-inch layer of compost on top of the mixed soil to add good bacteria.

Use a hand shovel to dig a hole for each seedling and plant. The hole should be 1 inch deeper than the size of the rootball. Refer to the instructions on the back of the seed package or on the planting stick to find out how far to space each plant. Hold the seedling at the base of the stem and gently remove it from the container. Loosen the roots with your fingers and place the seedling in the hole. Fill around the hole with the soil you removed. Spread a two- to 3-inch layer of mulch over the flower bed to add moisture and prevent weeds from popping up.