How to propagate roses by cuttings? A detailed guide to the latest cutting methods
Rose propagation by cuttings is divided into hardwood cuttings and softwood cuttings. Hardwood cuttings are taken in November each year along with winter pruning. Select healthy branches and cut them to about 10 cm, with three to four leaf buds, insert them into sandy soil, water thoroughly, cover with plastic film to keep warm and moist, and generally by April they will root, and by June they can be transplanted. For softwood cuttings, from February to June, take healthy softwood shoots 5 to 7 cm long from plants with dense sprouting and insert them into washed river sand, water thoroughly, cover with plastic film, water two to three times a day, ventilate at noon, and they will root in one month.
Preparation before rose cuttings
1. Weeding and digging. Mix into each mu of cutting bed 200 kg of decomposed farmyard manure (cow dung) and 25 kg of superphosphate as base fertilizer. To reduce disease in the cuttings, disinfect the soil before cutting: spray the soil with a 500 to 800 times dilution of 50% tebuconazole wettable powder or an 800 times dilution of 50% carbendazim wettable powder, then cover with plastic film for 3 to 4 days, and take cuttings 1 week after removing the film.
2. Number of cuttings. There are currently 9 solar greenhouses available, and the specification of each solar greenhouse is: 60*8 (m). With a cutting density of 5*5 (cm), excluding the area taken up by the ridges, each greenhouse can hold 160,000 cuttings.
Rose cutting methods
1. Cutting selection. The quality of the cuttings is the key to ensuring rooting and improving the survival rate of rose cuttings. First, choose superior mother plants of vigorous growth and free from pests and diseases; second, the branches must have a good nutritional foundation, so the cuttings should be selected from thick, vigorous branches, requiring one-year-old branches with a diameter of 5-8 mm, preferably branches whose terminal flowers have just opened in the current year. Old branches of more than one year have a higher degree of lignification in the cortex, making rooting more difficult. Cut the cuttings to have 3-5 buds and a length of about 8-12 cm, make a slanted cut at the base about 2 cm below a node, make a flat cut at the top above a node bud, and seal the wounds with petroleum jelly or wax. Leave 2-3 pairs of leaves at the top of the cutting and trim part of the small leaves, while all the leaves at the base are cut off.
2. Rooting treatment. Before cutting, dip the base of the cuttings in 50-100 ppm ABT rooting powder or indoleacetic acid for 3-5 minutes to stimulate cell division, promote callus formation, achieve fast rooting and more roots, and improve the survival rate of the cuttings.
3. Cutting. As far as possible, cut, treat and insert the branches one after another. When inserting, be very careful not to damage the bark. Generally, first poke a small hole in the cutting bed with a small wooden stick or your finger, then place the cutting into the hole. The insertion depth is 1/2 to 2/3 of the length of the cutting. After inserting, press the soil firm with your hand and water thoroughly once so that the cutting and soil are closely combined. Be sure not to insert the cutting upside down.
4. Post-cutting management
① Build an arched shed and cover with shade net: the plastic shed can regulate the temperature and humidity of the soil and air, and the shade net can prevent direct sunlight and lower the temperature. The light transmittance of the shade net should preferably be 20% to 30%. In addition to covering the top of the seedbed with a shade net, hang curtains on the east and west sides of the seedbed to block light, so as to reduce morning and evening sunlight exposure. The optimal temperature for rose rooting is 20°C to 25°C. If the temperature is too high, in addition to covering with a shade net, you can also water to cool down and ventilate to cool down.
② Watering: In the early stage of cutting, the cuttings have not yet sprouted leaves, so water should not be supplied too much; generally watering once every 7 to 10 days is enough. After one month, the cuttings begin to root and sprout shoots, and water consumption gradually increases, so water once every 3 to 5 days. The amount of watering should be determined by soil moisture and air humidity, keeping the soil moderately dry and moist.
③ Fertilizing: The cuttings do not need much fertilizer. Since base fertilizer was applied when preparing the land, there is no need to fertilize the soil again before the seedlings are transplanted, but foliar fertilization is needed. That is, one month after cutting, apply foliar fertilizer once every half month, alternating 0.3% urea liquid fertilizer and 0.2% monopotassium phosphate liquid fertilizer, to promote rooting.
④ Weeding: Remove weeds in the cutting bed in time, but do not disturb the seedlings.
⑤ Hardening off: Half a year after the seedlings root, appropriately extend their ventilation and light time to improve the seedlings' ability to adapt to the external environment.
Precautions for rose cuttings
1. The shoots selected for cutting should not be too tender, nor should already lignified branches be used; it is suitable to choose thicker branches with a dark green color showing through.
2. Ring-bark a strip of outer bark about 0.2-0.3 cm wide at a point 1 cm below a bud eye, and then cut it off for cutting one week later; the survival rate is the highest this way. To ensure 100% survival, the air layering propagation method can be used. That is, wrap mud around the notch, and roots will definitely appear in about a month. The disadvantage is that air layering is only suitable for strong branches, and the quantity is small and the speed is slow. It is not as fast and simple as the cutting method, because the branches used for cuttings can even be the remaining branches after pruning roses, and dozens of seedlings can be propagated at one time.