Summarize:

Prepare to transplant gaura seedlings to an outdoor location after the threat of frost has passed in the spring. If you choose to purchase an established gaura seedling or plant from a garden nursery instead of growing one from seed, the same transplanting guidelines still apply. Note that many perennial varieties of gaura can be planted after the threat of frost passes in the spring or at the very beginning of autumn, before frost becomes an issue. Annual varieties must be planted in the spring, however. Gaura does best when planted in areas receiving full sun, but it can also tolerate spots that receive partial sun and light shade. You must choose a spot with well-draining soil. If your garden is filled with heavy soil, you must amend it before transplanting the gaura seedlings. Gaura shrubs develop a long taproot, so you will need to amend the soil to a depth between 1 and 2 feet (30.5 and 61 cm). Spread 6 inches (15.24 cm) of light organic matterpeat moss, compost, or sandover the top of the planting area. Use a shovel to dig the additive down into the soil to the appropriate depth. Make sure that the soil and organic material are evenly mixed. The soil should look notably looser when finished. Also note that the soil does not need to be especially nutrient-dense, but it should be fairly neutral with a pH between 5.5 and 7.2. Use a shovel or a trowel to dig a planting hole for the seedling. The planting hole for each seedling should be twice as wide as the seedling's current container. The depth of the planting hole should only be about as deep as the current container, though. Avoid planting seedlings too deep. The top of the root mass should be just beneath the surface of the soil. Before you remove the seedling from its current container, give the soil a thorough watering. Watering the soil makes it more compact and easier to move. Carefully remove the seedling from its container and center it in the planting hole. Hold the plant securely at the base of the main stem, just above the surface of the soil and the root mass. Slowly invert the container until it is tipped diagonally downward. Squeeze the sides of the container with your other hand or tap on the container with the handle of your trowel or shovel. This should loosen the plant and free it from its container. Grab the bottom or side of the removed mass. Carefully place the plant right-side-up in the planting hole. Continue to hold it steady above the root mass with one hand. Use your free hand to fill the rest of the planting hole with soil. Once the plant is stable, let go of it and use both hands to gently pat the soil down. The soil around the plant should be fairly loose but still packed well enough to hold the plant in place. Give the entire planting site a thorough watering to help settle the soil. Gaura does well when planted in nearby clusters or planted around other perennial shrubs. Small varieties should be spaced 8 to 12 inches (20 to 30 cm) apart. Large varieties should be spaced 20 to 36 inches (50 to 90 cm) apart. Planting the gaura close together can prevent the roots and stems from becoming too leggy.
Transplant in the spring. Choose a sunny spot. Provide plenty of drainage. Dig a hole twice as wide as the container. Water the seedling well. Transfer the seedling from the container to the planting hole. Pack the soil around it. Plant separate gaura seedlings close together.