What should be the main pole of Hundred Days Red?

Zinnia is one and a half meters high and its trunk is about 5 cm.

Centipede, also known as begonia, prurigo and so on. , belonging to Lagerstroemia of Lysimachiaceae. Beautiful tree shape and smooth bark. Rich and gorgeous colors, dense and elegant flowers, crape myrtle in summer and autumn, blooming for several months. It has certain cold resistance and drought resistance, and neutral to slightly alkaline sandy loam is the best, which is more drought-resistant and afraid of waterlogging. The flower bud is formed after the new shoots stop growing, which is beneficial to the flower bud differentiation under the condition of high temperature and little rain.