Introduction to Several Propagation Techniques for Japanese Spindle (Euonymus japonicus)

There are many propagation methods for Japanese spindle (Euonymus japonicus). Several commonly used methods are briefly introduced below:

1. Cutting method: The cutting method is further divided into hardwood and softwood cutting methods. Hardwood cuttings are carried out between October each year and the end of March of the following year. For units with sufficient source material, the cuttings can be cut slightly longer; for units lacking source material, the cuttings can be slightly shorter. The cuttings are 8 to 15 cm long, and the insertion depth is generally 3 to 5 cm. Roots can grow after 1 month. As long as cuttings are made according to the method introduced below, well-grown seedlings can be obtained quickly:

1) Prepare a sand bed with good drainage, and disinfect the sand bed with potassium permanganate or carbendazim two days in advance.

2) Prepare alcohol and plant rooting powder, and mix the solution according to the instructions.

3) When cutting the cuttings, do not choose shoot tips that are too tender; those with a high degree of lignification are easier to root and sprout.

4) When pruning, keep the main stem and cut the side branches, and leave at least one bud at the base to facilitate the next cut.

5) Remove the lower leaves of the cuttings and keep 2 to 3 leaves at the upper part. After the cuttings are trimmed, soak them in rooting water.

6) Use a small shovel to make a furrow in the sand bed, place the cuttings at 5 to 10 cm intervals, and after placing them, cover with soil and press firmly. The row spacing is 10 to 20 cm.

7) The cutting process requires maintaining appropriate temperature and humidity. Watering should be based on temperature and humidity, and the leaves must always be kept moist. Do not overwater, as this prolongs rooting time. After the seedlings root, watering can be appropriately reduced.

8) After cutting, roots generally appear in about 30 days, and they can also be potted at the appropriate time. The potting nutrient soil can be prepared with sand, soil and peat soil each accounting for one third, to facilitate aeration. Do not fill the pots too full.

2. Single-bud cutting method: The single-bud cutting method can quickly propagate Japanese spindle (Euonymus japonicus) seedlings. Cuttings are carried out between May and October. The bud piece is preferably 1 to 2 cm long, one bud with one leaf, and the leaf must be kept intact. The knife used to cut the bud must be very sharp, and the bud piece should be inserted promptly after cutting. Each square meter of cutting bed can hold 500 to 1000 seedlings. Roots form 1 month after cutting, buds begin to sprout after 40 to 45 days, and after 2 months the seedlings can reach 10 to 15 cm in height.

3. Leaf cutting method: Select mature leaves as cuttings. The leaf stalk used for cutting must be complete. When taking the leaves, do not use scissors; it is best to twist the leaf stalk off from the base of the bud by hand, and insert them as they are taken, or place the leaves in a basin of clean water. Storing the leaves for too long will reduce the survival rate of cuttings. The insertion depth is 2 to 3 cm. After 20 days of cutting, callus tissue can form at the base of the leaf stalk; after 30 days, new roots grow from the callus tissue; after 50 to 60 days, young buds form on the root primordium; and after 70 to 80 days, the young buds break through the soil and grow into new plants. One square meter of cutting bed can hold 1000 to 1500 leaves, and the survival rate can reach more than 95%.

4. Seed sowing method: Japanese spindle (Euonymus japonicus) bears fruit early, has a large seed yield, and a high seed germination rate. When the fruit skin cracks, it must be harvested promptly, otherwise the mature seeds are easily eaten by birds. After the seeds are harvested, remove the red aril promptly. When removing the seed coat, use gentle force; too much force can easily crush the seeds. After the seeds are dried in the shade, store them with moist sand. The sand should not be too wet; high humidity makes the seeds prone to mildew and rot. The storage room temperature must not exceed 15 degrees; when the room temperature exceeds 15 degrees, the seeds are prone to germinate early. After the soil thaws, sow as early as possible. Sowing should be early rather than late. If sowing is late, the air temperature and soil temperature rise, the seeds root and sprout quickly, and the seed roots are long; during sowing, the seed roots are easily broken, causing damage to the seeds. Seedlings propagated from seeds show obvious variation, especially in leaf shape, which varies greatly. Among seedling plants, 50% to 60% of seedlings have leaves the same as the mother plant, 20% to 40% of seedlings have leaves that become pointed, and 1% to 10% of seedlings have leaves that become broad and large. Regardless of how the leaf shape changes, the tree-like trait and fast-growth habit of seedlings propagated from seeds are almost the same as those of the mother plant. However, it should be noted that when propagating seedlings, do not easily throw away those pointed-leaf type seedlings.

5. Grafting method: Although Japanese spindle (Euonymus japonicus) shows a tree-like trait and grows 3 to 5 times faster than ordinary large-leaf Euonymus japonicus, for Japanese spindle to grow into large-sized seedlings with a diameter at breast height of 5 to 6 cm, it takes at least 6 to 8 years, or at most 10 to 15 years or longer. To cultivate large-sized, large-quantity seedlings within 5 to 6 years, it is necessary to first cultivate Euonymus bungeanus used as rootstock. Euonymus bungeanus has a well-developed root system, a high transplant survival rate, and fast growth, and can be cultivated into seedlings with a diameter at breast height of 5 to 6 cm within 3 to 4 years. Japanese spindle grafted onto Euonymus bungeanus rootstock forms a crown early, and the grafted seedlings have strong cold resistance.