The propagation methods of tree peony can be divided into sexual propagation (sowing) and asexual propagation (grafting, Ramet) .

1. Sow

Because of the large propagation coefficient, sowing is used to breed rootstock and breed new varieties. The cultivation of medicinal peony is mainly propagated by seed.

In the wild state, tree peony mainly propagates its offspring by seeds. After long-term artificial cultivation, peony stamens and pistils degeneration, change into petals, most of the loss of fruit-bearing capacity. Therefore, asexual propagation has become the main propagation method to keep the fine characters of tree peony. According to the observation, the higher the evolution degree of Peony Flower Type (that is, more flower layers, Rise) , the more serious the degeneration of pistil and stamen, the smaller the possibility of fruiting. Only single and semidouble varieties and Fengdan can bear seeds.

Peony seeds are usually collected in late July to early August. The seed coat inside the pod changes from white to blue. Peony species like tender does not like old. Not fully mature peony seeds of its many characteristics are not fixed, not only after planting is easy to germinate, but also easy to produce variation, the formation of new varieties. The mature peony seeds had a low germination rate when they were sown, and some of them did not germinate until next year.

The peony seeds take root after 15-20 days after sowing, then germinate and burrow from late February to early March of the following year, remove the mulch in advance, and water them once every 10-15 days with little rain in some dry areas, thin manure may be applied after April with watering. According to this method, the seedlings can be used for grafting or transplanting after two years of sowing, and after 3-5 years they can blossom successively. However, most of the non-grafted seedlings had white single-layer flowers and few had pink multi-layer flowers.

2. grafting

Grafting is the best method to propagate peony varieties and keep the good varieties and genetic characters. It can propagate quickly and increase the propagation coefficient. The ornamental quality and application value of peony were improved by grafting.

(1) selection of rootstocks

The root of 2-3-year-old seedlings of Paeonia lactiflora or paeonia lactiflora was used as the grafting rootstock, and the seedling with the diameter of 1cm or more was used as the rootstock.

(2) Scion selection

The Scions should be selected from the healthy plants, which are the first-year-old branches with strong sprouting shoots and pith and solid, and the second-year-old branches with strong sprouts and full sprouts, which contain more nutrients, and the second-year-old branches with strong sprouts, good for wound healing and survival. The scions are generally about 6 ~ 10 cm long with robust terminal buds and one or several small lateral buds. The scions should be clipped or jointed and not put in for long.

(3) grafting method

1 grafting: the grafting time of peony is usually from the first ten days of September to the first ten days of October, and the suitable temperature is 15 ~ 28 °C. By:

Dig out the rootstock to clean the soil on the root, put in 500 times isofenphos-methyl and topsin mixture soaked in 15 to 20 minutes, remove and dry the liquid medicine. Cut off the rootstock above the rootstock with the eye of the bud, split it with a sharp blade from the middle, and insert the cut Scion, aligning the cambium (that is, the cortex) ; if the rootstock and scion are not of the same thickness, just align it on one side. Tie with bast from top to bottom, then apply evenly with a thick and moderate paste on the incision, be sure to completely paste the wound. According to the provisions of deep planting, planting depth to the wound and natural ground is appropriate. Then the soil for the ridge, Ridge High to be able to completely bury the degree of Scion, too deep impact on the survival rate, too shallow scion easy to dry. Can not be watered within 20 days, so as not to affect the healing; first ten days of the following March unearthed alive, the general survival rate of more than 80% . After the survival of a number of drought in mid-march after half-monthly watering, watering twice in the water ploughing and weeding once; Phosphate and potassium fertilizers (5 ~ 7 kg per mu) can be applied once in late June, and can be sold or transplanted out of the garden after two years.

2 Bud Grafting: the bud grafting of tree peony is mainly used for changing varieties or cultivating a multi-colored plant. Bud grafting time should be from early May to late June, the operation time should be in 10 ~ 17 hours, at this time the cortex should be separated, adhesive. The axillary buds on the grafted part of the rootstock were removed together with cambium to retain the intact woody bud base, and the buds on the scion were peeled off in the same way and quickly sheathed on the rootstock bud base. Note that the two should coincide with each other, and finally with graft tape tight. The next month, when the bud is considered to have survived, remove the rootstock with tape to remove vegetations. The leaves on the rootstock should be retained to concentrate nutrients on the bud, which is conducive to the formation of full flower buds in the current year, flowering the following year.

3 subcutaneous: the time must be in early September to early October. The wound heals easily when the temperature is 20 ~ 25 °C. The length of the scion is 4 ~ 8 cm, and the flower bud is usually selected, and the two sides of the scion should be cut at 2 ~ 3 cm below the Scion, the long and short sides should be about 3 cm and 1 cm respectively, and the cut should be smooth. The thick lateral branches were selected as rootstock, and a 2-3cm long interface was cut on the side of the smooth upper branches. The scion is inserted into the base of the rootstock notch slightly obliquely, so that the two layers are closely connected and compact; if the thickness is not the same, one side can be aligned. Tie the joint from top to bottom with grafting tape, hemp rope and other materials, then cover the joint and the joint with a plastic bag, tie the plastic bag mouth tightly at a distance of 1 cm from the joint, so as to keep the temperature and moisture, and avoid the infiltration of rain water, improve the survival rate.

3. Ramets

Ramets are also called ramets. Tree peony is a cluster shrub, most varieties of roots often produce adventitious buds and germination branches. There are more than ten branches in a cluster of peony peonies, and there are 3 ~ 5 roots under each branch to supply nutrient and water, and the branches are connected with each other, therefore, in the Ramet reproduction must be aware of the root of the relationship between the interconnection, along its”Texture” natural potential for ramet, must not be arbitrary pull hard cent. In Luoyang, Ramet breeding is usually carried out in early October and not later than the end of November. If the time ramets, peony new root many, the next year vigorous growth, late ramets, its new root less and short, next year germination because of new root less, poor absorption of water and nutrients, seedling growth weakness or even death.