A Detailed Guide to the Latest Method for Grafting Camellias onto Oil Tea Trees

There are many methods for using oil tea trees as rootstock to graft camellias. Currently the most widely used are the cut-trunk bark-peeling graft and the uncut-trunk subcutaneous branch graft. When using the cut-trunk bark-peeling graft, a portion of the original canopy's nutrient branches must be retained, and depending on the size of the rootstock, 24 scions should be grafted symmetrically on each rootstock. Let's take a look together below!

Camellia uncut-trunk subcutaneous branch graft

1. Scion preparation: Cut the scion into short pieces 23 cm long, with both ends shaped like a horse's ear, each bearing one leaf and one bud. Then on the side opposite the leaf stalk, shave flat with a knife, cutting slightly into the xylem, and cut off one-third or one-half of the leaf blade.

2. Rootstock preparation: At a point 50-80 cm above the ground on the trunk, wash the grafting site with clean water, then use the tip of a knife to carve an “n” or “H” shape, deep enough to reach the xylem, with a length matching the scion and a width determined by the thickness of the scion. Tear the bark open from top to bottom.

3. Inserting the scion and wrapping: Insert the prepared scion into the bark slot of the rootstock, cover the scion with the bark strip of the rootstock, and wrap with elastic plastic film tape.

Camellia cut-trunk bark-peeling graft

1. Trunk cutting: For each tree, select 24 main branches of the rootstock with appropriate branching angles, straight and smooth trunks, and no pest or disease damage. Saw them off 50-80 cm above the ground, keeping 2-3 as nutrient branches and clearing away all remaining branches.

2. Washing the rootstock: Wipe the graft interface and the bark 5-7 cm below the interface with clean water.

3. Smoothing the rootstock: Use a grafting knife to smooth the saw cut, with the cut surface higher on the inside and lower on the outside.

4. Scion preparation: On the opposite side or side of the bud, make a flat cut at the interface, cutting slightly into the xylem, with the cut surface 1.52 cm long. On the opposite side, make a short slanted cut at a 30° angle, forming a horse's ear shape. Generally the scion has one leaf and one bud, with one-third or one-half of the leaf blade cut off.

5. Cutting the rootstock: Depending on the size and length of the scion, use a grafting knife to make two straight cuts on the rootstock, cutting only to the surface of the xylem, then pry the bark open.

6. Insertion: Place the long cut surface of the scion against the xylem of the rootstock cut, align the straight edges, leaving a slight white edge exposed, and use the rootstock bark strip to wrap and seal the short cut surface of the scion.

7. Wrapping: Use plastic film tape with a certain degree of elasticity to wrap the interface from bottom to top, taking care to prevent the scion from shifting.

8. Moisture retention and shading: Put a suitably sized plastic bag over the rootstock to retain moisture, and tie bamboo sheath or waste kraft paper in an east-west direction on the outer layer of the moisture-retaining bag for shade.

Method for grafting camellias onto oil tea trees

1. Grafting time: The grafting time is best between June and July, when the new shoot leaves of the camellia scion have already unfolded and the temperature is relatively high, so the graft wound heals quickly and the survival rate is high.

2. Grafting method: Use the cut grafting method within the branch grafting techniques. Because the grafting site is relatively high, we often call it “high grafting to change the head”.

① Rootstock treatment: There are two methods for treating the rootstock. One is to graft between June and July, selecting 3 to 5 main branches evenly distributed and 2 to 5 cm in diameter on the oil tea tree as grafting branches, cutting them off with a hand saw, then using a sharp grafting knife to smooth the saw cuts before grafting. Thicker branches can have several scions grafted around their perimeter. The second is to cut back 3 to 5 evenly distributed main branches on the oil tea tree in the previous winter to stimulate adventitious shoots, then select and keep 3 to 5 adventitious shoots on each branch and tend them carefully. After the adventitious shoots have become semi-lignified between June and July, grafting is carried out. This is also called the green branch grafting method or softwood grafting method.

② Scion selection: From the mother tree of the selected ornamental camellia variety, select one-year-old branches from the upper outer part of the canopy that are robust, free of pests and diseases, and have plump buds as scions.

③ Grafting tools and auxiliary materials: Prepare packing cord, plastic film strips, white plastic cover bags, a cut grafting knife, pruning shears, a hand saw, etc.

3. Cut grafting operation method

① Cut the scion into small sections 5 to 6 cm long, each ensuring 2 to 3 lateral buds. To reduce evaporation, cut off half of the leaf blade. At 1 cm below the lower bud of the scion, cut a long slanted surface about 2 to 3 cm long, and on the opposite side of the long surface cut a short surface within 1 cm in length. Smooth the cut end of the rootstock, choose a smooth spot at the edge of the xylem on the rootstock cross-section and cut straight down with one stroke. The length and width of the rootstock cut should correspond to the long surface of the scion. Then insert the long slanted surface of the scion into the rootstock, align the cambium on one side, and wrap the bark of the rootstock cut around the outside of the scion. If the rootstock is thick, several scions can be grafted around its perimeter and tied together after grafting. Use plastic film strips about 1 cm wide (with a certain degree of elasticity) for tying, and the film strips must be pulled tight when tying.

② After tying the rootstock, cover it with a white transparent plastic cover bag and tie the mouth of the bag securely with packing cord, which helps retain moisture. In places with too strong sunlight, the grafted plants should be shaded during care. During the care period, the sprouts on the rootstock should be wiped off at any time to reduce nutrient consumption.

③ When changing the head by high grafting on oil tea trees, we can graft camellia varieties with similar flowering periods onto one oil tea tree, producing a “Shiyangjin” camellia tree with two flowers on one tree or multiple flowers on one tree, to improve the ornamental value of the camellia.

4. Post-grafting management: Within 1 month after grafting, take care to protect the moisture-retaining bag, prevent damage by people and livestock and prevent pests from biting through the moisture-retaining bag. When the new shoots touch the moisture-retaining bag, the bag can be removed (best done in the evening or on cloudy and rainy days). Keep the shading material in place, seal the cuts with wax, remove sprouts promptly, and when new shoots are found to be growing excessively, pinch out the terminal buds. Set up supports promptly to prevent wind breakage and damage to new shoots by pests and diseases.