Dig a hole in the potting soil deep enough to accommodate the roots of the rosemary cutting. The depth will depend on the size of the cutting. Put the rosemary cutting into the hole and cover the roots with soil. Pack the soil around the plant gently so that the plant stands on its own.
Stand a wooden or bamboo stake in the soil firmly next to the rosemary cutting. Using ties, stake the plant to it. Use twist ties to secure the plant to the stake at 2-inch intervals. Be careful not to cut into the plant when securing.
Water thoroughly, until water runs out of the drainage holes in the bottom of the pot. Put the plant where it can receive six to eight hours of sun daily.
Feed the plant using 15-30-15 liquid fertilizer weekly. Remember to water the plant when the top 1 inch of the soil becomes dry, usually every one to two days.
Adjust the ties as the plant grows to make sure it remains secured to the stake. Allow the plant to grow to the desired size, usually 12 to 36 inches. This usually takes six to eight weeks.
Strip the leaves from the bottom one-third of the stem and begin to prune the top into the desired shape.
Continue to pinch out new shoots from the stem and to prune the top as it grows.
Feed the topiary monthly with the liquid fertilizer, once established, and continue to water it as the top 1 inch of the soil becomes dry.