The keel propagation is mostly cuttage propagation. Keel is a succulent plant. When it is cut off, it will flow out of the pulp. It can be sealed with plant ash, stored in the shade for 7 days to 10 days, and then cut after the plant shrinks. One is to cut the keel into sections, and the upper and lower incisions are closed with plant ash, and the cutting length is 20 cm to 25 cm. The other is branches taken from keel branches, which can be cut after drying, but they are too small and tender to take root. This kind of cutting only has a small wound at the root, and the cutting takes root quickly. The matrix for cutting the keel needs vermiculite, pearl powder particles, pure river sand and no soil. Single-plant cutting or multi-plant centralized cutting can be carried out. After cutting, water is poured, only to the cutting place, where there is plenty of sunshine. Water as little as possible during rooting, don't dry it, and wait for 30 to 40 days to take root. Transplanting after rooting, the pot soil needs to be evenly mixed with 1/2 river sand and 1/2 loam soil, then planting, pouring 2% potassium permanganate water, not only disinfecting the soil, but also watering the soil. Tall plants can be tied and fixed with sticks. When cultivated in sunny places, it is still necessary to control the amount of water, which should be dry and not wet. There are many kinds of dragon bone columns, such as cluster, three columns and nine columns. The author thinks that nine columns and twelve columns are spectacular. The specific shaping method is as follows: When the nine-column plant grows to 20 cm to 30 cm, cut off the top with a sharp knife and seal it with plant ash immediately. After the plant grows branches, only the top three branches are left, one at each corner, and the rest are erased. When the second layer grows to 25 cm to 30 cm, the top is cut off again. After the branches are born, choose three branches, three at each corner, that is, 1, 3, 9-shaped keel. The angle selection method of twelve columns is the same as above, except that when the length of nine columns is 20 cm to 30 cm, the top is cut off, and then three branches are cultured, and each angle is selected as 1 or 3. Other twigs are erased with the increase of length, keeping the tree shape consistent. When the tufted columnar plants grow to 40 cm to 50 cm or 30 cm to 40 cm, cut off the top and let them grow naturally to form a multi-headed keel, but the selection should be orderly and not disorderly. When the growth height of the dragon bone column reaches 2 meters to 3 meters, many branches are formed, which is easy to cause top-heavy and unstable, and should be fixed with wooden sticks in time. Dragon bone column needs plenty of sunshine, the branches are blue-green, the leaves are like fish scales, and they will glow under the sunlight, with many bodies and sharp swords. Very spectacular, it is a good potted flower. Longguzhu is not cold-tolerant, but drought-tolerant, and likes dry loam. It should be kept indoors in winter in the north, planted in the open field in the south, or used as a fence, which is not only a green barrier, but also beautifies the courtyard, and flowers and fruits can be seen in summer. Dragon bone column is known as "universal rootstock", which can be grafted with Rosa davurica and Crab claw orchid, and it is colorful. Dragon bone column has few pests and poor indoor ventilation, which is easy to be harmed by red spider. It is found that the top of the branch is reddish brown with mesh, and it can be sprayed with omethoate 1000 ~ 2000 times, and the dosage should not be too large to prevent the head from festering.