What are the common propagation methods for flowers?

There are many varieties of flowers in nature, and if you want to grow more flowers, you need to use certain propagation methods. What are the common propagation methods for flowers?

Common propagation methods for flowers

Flower propagation is divided into sexual propagation and asexual propagation. Sexual propagation is mainly seed propagation, while asexual propagation includes division, cuttings, layering and grafting.

1. Seed propagation

Seed propagation is generally carried out in spring and autumn. It can be done either in open ground or in pots. Generally speaking, the appropriate planting soil should be chosen according to the flower variety, and before sowing, the seeds should be awakened and germinated to increase the germination rate.

2. Division propagation

Division propagation is mostly used for propagating perennial herbaceous plants. Sometimes, in order to renew old plants, the division method is also often used to promote the growth of new plants. Division propagation can be roughly divided into the following categories:

① Tuberous root type: For example, the roots of the dahlia are thick and form tubers, and buds sprout from many places on the root crown. The tuberous roots can be cut apart (must have buds attached) and planted separately, thus propagating into a new plant.

② Corm type: The stem is shortened and thickened, becoming flatly spherical or spherical, such as tulip, gladiolus, freesia, tuberose, etc. The small natural offsets produced on the corms and bulbs are separated and planted to cultivate new plants. Generally, very small daughter corms cannot bloom in the first year and only bloom in the second year.

③ Rhizome type: Thickened underground rhizomes lie horizontally underground, such as canna and bamboo. On each long stem, use a sharp knife to cut apart the portion of the rhizome with 3-4 buds and plant it separately.

④ Perennial plants: Clumping perennial plants, after being planted for three to four years, or after being grown in pots for two to three years, may become too large as clumps and can be propagated by division in spring and autumn. Dig them out or combine this with repotting, and the root system will naturally separate in many places. Generally, they are divided into 2-3 clumps, each with 2-3 main branches, and then planted separately. Examples include daylily, iris, Cymbidium goeringii and other flowers.

⑤ Clumping and suckering shrubs: For clumping shrub flowers, dig them up in early spring or late autumn and generally divide them into 2-3 plants for planting, such as wintersweet, nandina and lilac. Another category is flowering trees and shrubs that readily produce root suckers. The suckers produced from the roots of the parent plant are separated with roots and planted separately, such as asparagus fern, winter jasmine and tree peony.

3. Cutting propagation

① Stem cuttings: Select healthy branches from mature plants as cuttings. Due to differences in material and timing, they are further divided into hardwood cuttings and softwood cuttings.

Hardwood cuttings: After leaf fall or before bud break the following spring, select the middle part of mature, healthy, well-developed, pest-free one- or two-year-old branches, cut them into cuttings about 10 cm long with 3-4 nodes. The cut should be close to the node, and the upper end should be cut at a slant to facilitate drainage, then inserted into the soil.

Softwood cuttings: That is, cuttings from current-year young shoots. Cut branches 7-8 cm long, remove the lower leaves, keep a few upper leaves, and then insert them for rooting. Examples include chrysanthemum, poinsettia, geranium and begonia.

Semi-hardwood cuttings: Mainly cuttings of evergreen flowering trees and shrubs taken during the growing season. Take current-year semi-mature shoot tips about 8 cm long, remove the lower leaves and keep two upper leaves, and insert them into the soil about 1/2-2/3 deep. Examples include osmanthus and Chinese rose.

② Leaf cuttings: That is, using plant leaves as cuttings, generally mostly used for plants with strong regenerative capacity. They can be divided into whole-leaf cuttings and partial-leaf cuttings. When using leaves with petioles for cuttings, they root very easily. The rooting sites of leaf cuttings include leaf margins, veins and petioles. African violet and Haemanthus can be propagated by this method.

③ Leaf-bud cuttings: A cutting method in which a leaf is attached to a leaf bud and a small amount of stem, intermediate between leaf cuttings and stem cuttings. The stem can be cut near above the bud, and a little longer below the bud, so that growth vigor is strong and rooting is robust. Generally, cuttings about 3 cm long are suitable. Rubber tree, dieffenbachia, hydrangea and camellia can all be propagated by this method.

④ Root cuttings: Using roots as cuttings to propagate new seedlings, only suitable for species whose roots can produce new shoots. Generally, when using root cuttings, the larger the root, the stronger the regenerative capacity. The roots can be cut into 5-10 cm lengths and inserted at a slant or buried horizontally to induce adventitious buds and fibrous roots. Plants such as peony, wintersweet, tree peony, African daisy, snow willow and persimmon can all use root cuttings.

4. Layering propagation

Layering is a method of propagation in which a branch of a plant is buried in the soil without being detached from the parent plant. It is mostly used for flowers that are difficult to root from cuttings, such as wintersweet, osmanthus, edgeworthia and Aglaia odorata.

① Simple layering: Take a branch close to the ground as the layering material, bury the branch 15 cm deep in the soil, make cuts or ring-bark the buried part of the branch, leave the tip of the branch exposed above ground, fix it with a bamboo hook, cover with soil and press firmly. Forsythia, Podocarpus macrophyllus, kerria and winter jasmine are commonly propagated by this method.

② Mound layering: This method is mostly used for clumping flowering trees and shrubs. In the first year, cut back the aboveground part to promote the sprouting of side branches; in the second year, wound the bases of the side branches and mound soil over them. After rooting, transplant them separately. Spiraea, winter jasmine and Forsythia viridissima can use this method.

③ Wavy layering: Bend the branch to the ground, make several cuts on the branch, bury the cut parts in the soil, and after rooting, cut and transplant them to form new individuals. It is mostly used for plants with long and easily bent branches.

④ Air layering: Select mature, healthy current-year branches, perform ring-barking or wounding, wrap the ring-barked area with plastic film, tie it tightly with string, and fill it with moss and soil of suitable moisture. After new roots grow, cut it off, remove the film, and plant it as a new individual. Layering does not detach from the parent plant, and all nutrition comes from the parent plant, so attention should be paid to pressing the soil firmly. The time to separate from the parent plant varies with the variety. When planting, bring as much soil as possible to protect the new roots and help survival. This method is usually used for plants with an upright plant shape, hard branches that are not easy to bend, and that do not readily produce root suckers.

5. Grafting propagation

Grafting is a method of propagating new plants by grafting part of one plant onto another plant. The branch used for grafting is called the scion, the bud used is called the graft bud, the plant being grafted onto is called the rootstock, and the successfully grafted seedling is the grafted seedling. Callus tissue forms between the scion and the rootstock. When the scion sprouts new branches and leaves, it indicates that the graft has taken. Cutting off the sprouts of the rootstock then forms a new individual. The rootstock should be selected from the same species or genus closely related to the scion, and should be a plant with strong adaptability and healthy growth; the scion should be selected from plump middle branches.

When growing flowers, everyone needs to choose the appropriate propagation method according to the flower variety.