How to graft roses? A detailed explanation of three grafting techniques

The survival rate of rose grafting is greatly affected by the grafting period. The best grafting period is from early September to mid-October, when the survival rate is highest. The temperature at the time of grafting is best between 18—25°C, and grafting should be done on a sunny day without rain. For rose grafting, different grafting methods show great differences in survival rate. Chip budding gives the highest survival rate; for this grafting method, mature and plump branches should be selected as budwood. The bud opening made at the time of grafting should be slightly larger than the bud plate. After inserting the bud plate, note that the upper end of the bud plate must expose a thin sliver of the rootstock cortex, to prevent the newly grown callus tissue from pushing the bud plate out. The film should be tied with moderate tightness, both to prevent the bud plate from moving inside and to avoid tying too tightly, which would affect the upward movement of water and thus affect survival. Four weeks after grafting, if the bud plate is green, the leaf stalk falls off at a touch, and the callus tissue has filled the bud opening, then it has survived, and the binding should be removed and the rootstock cut back. Unbinding is best done on a cloudy day without rain, preferably in the afternoon. If the bud plate is still green one week after unbinding, the rootstock can be cut back. The rootstock should be cut at a point 15 cm above the bud opening. After the bud plate sprouts, a second cutting back of the rootstock should be carried out, this time at a point 1 cm above the bud plate. After cutting back the rootstock, the leaf buds on the rootstock will successively sprout and should be removed promptly, so as to avoid consuming nutrients and affecting the growth of the grafted bud.

After the grafted bud sprouts, attention should be paid to fertilizer and water management and to the prevention and control of pests and diseases, especially downy mildew and aphids, and reasonable shaping and pruning should be carried out according to need.

According to current production practice and the mainstream methods of rose grafting, rose grafting methods can be divided into three types: woody chip budding, T-shaped budding, and large open-door budding.

1. Woody chip budding

Woody chip budding: On the sunny side of the rootstock 4 to 6 cm above the ground, use a single-edge safety razor blade to cut a shield-shaped incision 1 to 2 cm long at an oblique angle of 30° to 40°

Then, using the same method and the same size, select a plump and well-filled grafted bud on the scion stick.

Insert it into the already cut rootstock incision, and use a white plastic strip of moderate elasticity and width to bind it firmly from bottom to top, pressing the edge ring by ring, with moderate tightness.

2. T-shaped budding

T-shaped budding is likewise a popular method in current rose grafting production.

Use a short-bladed vertical knife to make a horizontal cut on the branchless sunny side of the rootstock 4 to 6 cm above the ground, about 5 to 8 mm wide, just reaching the xylem, then make a vertical cut downward from the middle of the horizontal cut, about 1.5 to 2 cm long, so that the cortex forms a T-shaped opening.

Cut the scion stick from the mother plant, remove the leaves but keep the leaf stalks, select a plump and well-filled grafted bud, use a sharp knife to make a horizontal cut about 0.5 cm above it, going about 3 mm deep into the xylem, then use the knife to push and cut upward from about 0.5 cm below the grafted bud, just reaching the xylem, up to the incision above the grafted bud. Use the knife to lift open the cortex of the T-shaped incision on the rootstock, insert the grafted bud into the incision, and after insertion make fine adjustments so that the horizontal cut of the grafted bud aligns with the horizontal cut of the rootstock without exposing the rootstock cambium; positioning it correctly in one go is ideal.

Once the grafted bud is properly placed, bind it with a plastic strip; when binding, the grafted bud must be left exposed. Although this method seems cumbersome and time-consuming, once proficient, one plant can be grafted within one minute, and the grafting survival rate is extremely high and the quality of survival excellent.

3. Large open-door budding

On the smooth, branchless sunny side of the rootstock 4 to 6 cm above the ground, use a short-bladed vertical knife to make a horizontal cut, just reaching the xylem, then aim at one end of the horizontal cut and make a vertical cut downward 1.5 to 2 cm, then at the other end of the horizontal cut make another cut in the same way. Both cuts should just reach the xylem, then make another horizontal cut about 0.5 cm below the horizontal cut, and use the knife to remove the cut-off small square piece of cortex to expose the xylem, then lift it open with the knife.

Remove the leaves from the scion stick but keep the leaf stalks, select a plump and well-filled grafted bud, use the knife to make a horizontal cut about 0.3 cm above the grafted bud, then aim at one end of the horizontal cut and make a vertical cut downward 1.5 to 2 cm, then at the other end of the horizontal cut make another vertical cut in the same way, then aim at the two vertical cuts and make a horizontal cut to form a rectangular bud plate with the grafted bud; all four cuts should reach the xylem.

Use a knife or your hands to lift open the rootstock cortex and quickly insert the grafted bud with fine adjustments. Align the two horizontal cuts of rootstock and scion and bind with a plastic strip, with moderate tightness. With this grafting method, the contact area between the cambium of rootstock and scion is large, and supply is rapid, which can greatly increase the survival rate and quality of survival. Whether grafting is carried out in summer or in winter with rootless rootstock, after grafting the cuttings are planted at a sparser density than ordinary rose cuttings. When planting cuttings, all cuttings should lean north at 70°, with the grafted bud side facing the sunny direction. Plant spacing and row spacing 5 cm×5 cm, planting depth about 3 cm.

Explanation of rose grafting techniques

Rose grafting is one of the most widely used methods for propagating roses. Grafting belongs to the category of asexual reproduction; it combines parts of two plants into one whole, which continues to grow as a single plant. In a grafting combination, the upper part is called the scion, and the part bearing the scion is called the rootstock. Some rose varieties are few in number and have striking flower colors, while own-root seedlings have weak root systems and grow extremely slowly; using vigorous rootstocks for grafting makes these rose varieties grow vigorously and enhances their disease resistance.

Grafting can also faithfully reflect the various traits of the original variety, with extremely strong heredity and stability. Through practical observation, for plants formed by growth and development after grafting, from the date of grafting to the opening of the first flower, the fastest takes only 23 days, and individual plants can even flower 1 to 2 days earlier; most grafted plants usually take about 40 to 45 days to flower. It can thus be seen that compared with cuttings, grafting can advance the flowering time.

Taking the Beijing area as an example: on June 15, grafting and cutting were done on the same day; around July 25, about 20% of the grafted plants could flower, while only about 10% of the cutting seedlings flowered around September 20 or even later. It can thus be seen that the advantages of grafting are very strong. Of course, grafting propagation is complex to operate and has relatively high technical requirements. The specific issues of grafting propagation are explained one by one below.

I. Factors affecting grafting survival

1. Selection of rootstock:

For rose grafting, first of all, a suitable grafting rootstock must be selected. The rootstock not only bears the roles of mechanical support and absorption and conduction of water and nutrients, it also controls the plant's function of absorbing organic matter and is responsible for the manufacture of various enzymes and the storage of nutrients, and it has a great influence on the various characteristics of the upper part of the plant, including stems, leaves, flowers, and fruits. Of course, the scion in turn also plays an important role in the growth and development of the rootstock root system. Various experiments have proved that the quality of the rootstock is one of the important factors related to whether ideal grafted rose seedlings can be produced. The rootstocks commonly used now are roses and their varieties, such as 'Fentuan' rose, 'Manniti' rose, Dutch rose, and Japanese thornless rose. These rose species have well-developed root systems and resistance to cold and drought, and have strong compatibility with the grafted varieties and stable heredity.

2. Grafting compatibility between rootstock and scion:

Grafting compatibility refers to the similarity of internal tissue structure, hereditary and physiological characteristics between rootstock and scion. Through grafting, it can promote the plant to heal and survive and to be physiologically compatible after survival. The manifestations of weak compatibility and strong compatibility are relatively complex. Generally speaking, the closer the kinship, the stronger the compatibility. Compatibility is strongest between the same variety or the same species. Grafting compatibility between different species of the same genus varies by species.

3. The cambium of both rootstock and scion:

The cambium parts of both rootstock and scion must be in close contact over a fairly large area; this is one of the factors for grafting survival. In theory, completely matching the cambium of both rootstock and scion is the ideal grafting result, but in actual operation it is very difficult to achieve, and one can only seek to achieve the largest possible area of contact.

4. Temperature, moisture, and oxygen conditions at the time of grafting:

Temperature is a necessary condition for cell activity; only cell activity, including cell division, can promote the growth of the scion.

Usually, different rose varieties can have rapid cell growth within a temperature range of 13°C to 32°C. When grafting outdoors, one should choose the period of the year with the above temperature and with the cambium in vigorous activity. Such conditions generally appear in spring, early summer, and September and October. The callus tissue grown from the cambium is composed of thin-walled and plump cells, which easily lose water and dry out, causing the scion to dry up and die. Therefore, the union must be tightly bound to maintain the moisture of the tissue. The rapid division of callus tissue cells is often accompanied by respiration, and at this time oxygen is indispensable. Therefore, using a plastic strip to bind the union has the dual effect of retaining water and promoting respiration.

5. Quality of rootstock and scion:

According to the growth law of the rootstock and the comparison between its cutting seedlings and seedling-grown plants, selecting one-year-old seedling-grown plants as rootstock for rose grafting is relatively ideal, because they have well-developed root systems, strong disease resistance, smooth main stems, and moderate thickness. Of course, using cutting seedlings for grafting also has its advantages, such as a short cutting time and easy rooting.

II. Grafting techniques

1. Disinfection of knives before grafting: When grafting, while ensuring the alignment of the cambium of rootstock and scion, it is also necessary to ensure that the cut surfaces of rootstock and scion are flat. The binding action should be nimble and quick, to avoid the cut surface oxidizing and changing color.

2. Selection and storage of scions: The selection of rose scions is directly related to the survival quality of the grafted seedlings and whether vigorous grafted plants can be formed. Stored scions can be taken out for grafting at any time, eliminating the trouble of collecting them just before grafting, saving a great deal of time, and allowing grafting at any time. The selection and storage of scions should pay attention to the following points:

(1) The scion stick must be healthy and free of pests and diseases; if it has powdery mildew, black spot, or red spider, etc., it must not be used.

(2) Usually, one-year-old or less-than-one-year-old scion sticks after flowering can be selected; from the second axillary bud below the bract, the entire flower-bearing branch can be used as a scion stick. Flower-bearing branches vary in length, from 150 cm long to about 10 cm short, and contain varying numbers of grafted buds; sometimes on the same scion stick the plumpness and fullness of the grafted buds differ, so buds should be selected individually. Generally speaking, the grafted buds taken from the middle part of the scion branch are most suitable for grafting, with the best survival rate.

(3) As long as the scion has plump grafted buds, it can be stored for later use at any time of the year; of course, in summer it should be refrigerated, and in winter it can be stored in sand. The time for refrigeration and sand storage must not be too long. Usually, the number of scions refrigerated and stored in sand should be roughly equal to the number of rootstock plants. Or the number to be refrigerated or stored in sand can be determined by the grafting speed. The prerequisite for refrigeration and sand storage is that moisture and temperature must be properly maintained; only with proper moisture and temperature maintenance can the normal physiological activity of the scion stick be maintained. Practice has proved that scientific refrigeration and sand storage are beneficial to the survival rate and quality of grafting.

III. Grafting period

According to the growth habits and growth laws of roses, grafting can be carried out at any time of the year, but specific situations must be analyzed specifically. When the temperature reaches above 33°C, the survival rate of grafting is relatively reduced; below 5°C, the grafted plant is in a dormant state, so using the winter dormant period for grafting is suitable.

IV. Grafting methods

According to current production practice and the mainstream methods of rose grafting, rose grafting methods can be divided into woody chip budding, T-shaped budding, large open-door budding, and rootless rootstock grafting.

1. Woody chip budding:

(1) On the sunny side of the rootstock 4 to 6 cm above the ground, use a single-edge safety razor blade to cut a shield-shaped incision 1 to 2 cm long at an oblique angle of 30° to 40°. Then, using the same method and the same size, select a plump and well-filled grafted bud on the scion stick and insert it into the already cut rootstock incision, and use a white plastic strip of moderate elasticity and width to bind it firmly from bottom to top, pressing the edge ring by ring, with moderate tightness.

(2) When inserting the grafted bud into the incision, the cambium should be aligned over as large an area as possible, without exposing the rootstock xylem. This method is simple and quick to operate and has a relatively high survival rate, but it has high technical requirements, and one must master the technique of matching rootstock and scion in one go.

2. T-shaped budding: T-shaped budding is likewise a popular method in current rose grafting production.

(1) Use a short-bladed vertical knife to make a horizontal cut on the branchless sunny side of the rootstock 4 to 6 cm above the ground, about 5 to 8 mm wide, just reaching the xylem, then make a vertical cut downward from the middle of the horizontal cut, about 1.5 to 2 cm long, so that the cortex forms a T-shaped opening.

(2) Cut the scion stick from the mother plant, remove the leaves but keep the leaf stalks, select a plump and well-filled grafted bud, use a sharp knife to make a horizontal cut about 0.5 cm above it, going about 3 mm deep into the xylem, then use the knife to push and cut upward from about 0.5 cm below the grafted bud, just reaching the xylem, up to the incision above the grafted bud.

(3) Use the knife to lift open the cortex of the T-shaped incision on the rootstock, insert the grafted bud into the incision, and after insertion make fine adjustments so that the horizontal cut of the grafted bud aligns with the horizontal cut of the rootstock without exposing the rootstock cambium; positioning it correctly in one go is ideal. Once the grafted bud is properly placed, bind it with a plastic strip; when binding, the grafted bud must be left exposed. Although this method seems cumbersome and time-consuming, once proficient, one plant can be grafted within one minute, and the grafting survival rate is extremely high and the quality of survival excellent.

Rose grafting time, tutorial on rose grafting propagation techniques

Grafting is a method often used to propagate roses, but for beginners who start propagating roses by grafting, improper operation will lead to a low survival rate of the grafted roses. Of course, when the grafting operation is done properly, the survival rate of roses is also good. The following is a detailed analysis of the steps of rose grafting, hoping it will be helpful to flower lovers who have newly become fans of roses.

Rose grafting time is generally better in mid-March, early to mid-July, and mid-to-late September

Grafting knife, pruning shears, gloves, tape, pencil, labels, scion, rootstock (generally the rootstock can be wild seedling-grown roses, or roses). There are quite a lot of tools; in fact, a simple razor blade and a utility knife are enough.

a. According to experience, if the rootstock needs to be dug from the wild, the rootstock can generally be stored for 2-3 days; if the rootstock root system is very well developed, it can be divided into two parts. The position pointed to by the hand is where it can be divided.

b. Once you unfortunately encounter crown gall, you should give it up completely; you cannot merely cut off the crown gall part and continue to use it.

c. Cut off 2-3 cm above the root system. Even if new buds appear on the branch, be merciless.

a. Use scissors to cut off the thorns.

b. According to the bud points and leaf scars, determine the up-down direction of the scion. The bud point is on top, and the leaf scar is below; this is an important way to distinguish whether the scion is upside down or right side up.

c. Cut the scion in the following way: cut vertically 1-1.3 cm, just enough to expose the white wood, and do not cut too deep. After cutting, place the spare scion in a dish of water to prevent it from drying out.

Cut the rootstock vertically; when cutting, be sure to be careful not to cut your hand, and also control the force well; do not use too much force and cut all the way through.

The scion and rootstock must be perfectly combined, otherwise grafting will fail due to nutrient supply; the scion may be allowed to deviate from the rootstock by at most 3 mm.

a. It is best to use grafting tape rather than adhesive tape. Wrap firmly from bottom to top, avoiding slipping and misalignment, and wrap well with tape.

b. If it cannot be transplanted immediately, it should be stored together with wet newspaper to prevent drying out. Chemical fertilizers must not be used, and the soil around the roots should be kept clean.

After planting out, it can be kept in a greenhouse, or a simple greenhouse can be made using plastic bags and kept in a sunny place. Keep the temperature above 10°C.

After about 7-10 days, we will see the buds gradually swell. If kept in a place at 5-6°C, it takes about 1 month for the bud points to grow. If beyond this time the scion branch wrinkles and turns black, it indicates that the grafting has failed. When the leaves extend, be careful that there is not too much moisture in the insulation bag. The greenhouse should maintain a certain humidity and temperature. After March, as the temperature rises, the bag can be completely opened, but frost in the morning and evening should be prevented; after the seedlings are stable, a certain amount of liquid fertilizer can be applied.