How to Build a Petunia Trellis in a Pot

Grown for its trumpet shaped blooms, the petunia (Petunia ? hybrida) adds continuous color to a landscape throughout the growing season. Specific varieties of this herbaceous annual, such as the "Wave" petunia (Petunia x hybrida "Wave"), produce trailing stems that may reach lengths of up to 4 feet, making them excellent candidates for container plantings. To create a better display of your potted petunia's blooms, install a trellis in the pot to lift the stems upward into a vertical mat of lush green foliage and color. Making your own trellis ensures that it fits your pot perfectly.

Tape measure

1/2-inch balsa wood sticks

Hand saw

Sandpaper

3/4-inch brad nails

Hammer

Twine string

Scissors

Cyanoacrylate glue

Turn the pot upside down and measure the distance across the bottom at its widest point. Record the measurement. Divide this measurement by 4 inches to determine the number of sticks you will need. For example, if the bottom measurement equals 12 inches, you will need 3 sticks. The reason for this is that each of the sticks will stand vertically, four inches apart.

Measure the height of the pot. Multiply the height by three to determine the correct length for the balsa wood sticks. For example, if the pot's height equals 12 inches, each stick should be 36 inches. Record the calculated measurement.

Cut each of the balsa sticks needed, using a handsaw, to the height you calculated.

Rub a piece of sandpaper along the sides and ends of the sticks, moving it in the same direction as the wood's grain to smooth any rough patches of wood and removing any splinters.

Lay two of the sticks vertically parallel on a flat surface. Position the two sticks so that the space between them equals the width of the pot's bottom. Place each additional vertical stick in between these two sticks, spacing them so there is 4 inches of space between every two sticks.

Cut a balsa wood stick into sections that will act as rungs. Make each rung equal in length to the width measurement you took from the bottom of the pot. Each rung will be placed horizontally across the top two-thirds of the trellis. Each rung should have about 4 to 6 inches below it before the next rung is placed. Cut as many rungs needed to accomplish this, and smooth each rung with sandpaper until it feels smooth to the touch.

Position the first rung across the tops of the vertical sticks, with its left end sitting on top of the leftmost vertical stick and its right end sitting on top of the rightmost vertical stick.

Hammer a 3/4-inch brad nail through the end of the run and into a vertical stick underneath it. Repeat this process, driving one nail into each point on the rung that sits over a vertical stick, so that the sticks are secured together.

Place a second rung horizontally across the vertical sticks, positioning it 4 to 6 inches below the first rung. Nail the rung in place in the same manner as before. Repeat this process to attach all the rungs to the top two-thirds of the vertical sticks.

Cut a 12- to 18-inch long piece of twine string. Center the string behind one of the points where a rung crosses a vertical stick. Wrap both ends of the string tightly around the rung and the vertical stick repeatedly, in a crisscrossing manner. Tie the ends of the string in a square knot. Trim any excess string with scissors. Repeat this process to tight each of the trellis' joints together, further stabilizing its construction. Apply one to two drops of cyanoacrylate glue to each knot to prevent it from coming loose.

Hold the trellis upright over the pot with the open ends of the vertical sticks facing downward. Position the trellis one-third of the way inward from one of the pot's sides. Push the trellis downward, inserting the ends of the vertical stick into the soil as far as they will go.

Plant the petunias in the pot, positioning them in front of the trellis. Select one of the petunia's stems, lifting it up against the trellis' surface. Wrap a plant tie around the trellis and stem. Tie its ends together in a knot, making the tie tight enough to hold the stem in place but loose enough to not cut into the stem or restrict its growth. Tie each stem to the trellis in this same manner, attaching one tie every 4 to 6 inches along the stem's length.

Spray paint the trellis with a color that matches or compliments the pot, petunia vines or petunia flowers.

Place your pot of petunias in an area that receives full sunlight with the trellis' front faced toward the sun to meet the petunias' light requirement.

Petunias, also grown as tender perennials, are winter-hardy in U.S. Department of Agriculture plant hardiness zones 10 and 11.

Do not touch the cyanoacrylate glue while it remains wet or you could blue your fingers to the twine.

Wear safety glasses and a dust mask to protect your eyes and lungs from airborne sawdust.

Wear gloves when working with wood to protect your hands from scratches or slivers.

Use a pot with holes in its bottom to provide the petunias with proper drainage.