Propagation Methods and Management Techniques for Cut Roses

Cut roses are one of the world's four major cut flowers, with more than 8,000 varieties bred around the world. Let's take a look at the propagation and management techniques for cut roses!

Cut roses are shrubs of the genus Rosa in the family Rosaceae. The leaves are alternate, odd-pinnately compound, with a flat, glossy surface. The flowers are solitary at the tips of the stems, double, and rich in form and color. They prefer a warm, humid environment with plenty of light. The optimum growing temperature is 15-25°C, and they require loose, fertile, well-drained moist soil.

Propagation is by cuttings, grafting, and tissue culture. For grafting, wild species of the genus Rosa are used as rootstock. Before cultivation, the soil should be improved and deeply tilled, with peat and rice bran added to make the soil loose and well aerated; in addition, sesame paste residue, bone meal, and barnyard manure are added as base fertilizer. During maintenance, excess flower buds and side branches should be pruned away promptly.

Temperature control is very important in greenhouse cultivation of cut roses, generally 20-28°C during the day, so in summer pay attention to ventilation and shading, which both lowers the temperature and reduces light, and the plants are less susceptible to disease in a well-ventilated environment.

During the growing period, keep the soil slightly moist; during dormancy, reduce watering to once a week. To ensure the quantity and quality of flowers, topdress promptly during the growing period, applying liquid nitrogen, phosphorus, and potassium. In winter, in addition to maintaining temperature, supplementary lighting is also needed.

Temperature Management

The most suitable growing and development temperature for cut rose production is 24-26°C during the day and 14-16°C at night. In winter, when the night temperature falls below 8°C, many varieties grow slowly, the branches become shorter, and deformed flowers increase. When the night temperature stays below 5°C for a long time, most rose varieties cannot produce new branches, or the new branches produced are shorter and blind branches increase. Therefore, low winter temperatures seriously affect the branch length, sprouting, and flower bud differentiation of cut roses, thereby affecting yield and quality. In summer, when the night temperature is above 18°C and the daytime temperature is above 28°C, most rose varieties have a shortened growth period, fewer petals per cut flower, smaller flowers, and a shorter vase life, which has a great impact on cut flower quality. The ideal day-night temperature difference is 10-12°C; too large a temperature difference causes black edges on the petals. In actual production in central Yunnan, controlling the daytime temperature inside the greenhouse at 26-28°C in summer and the nighttime temperature inside the greenhouse at 14-16°C in winter can guarantee high-yield, high-quality year-round production of export cut roses.

Soil Moisture Management

Roses are a crop that likes water but fears waterlogging. When soil moisture is insufficient, it affects the yield and quality of cut roses; conversely, too much soil moisture causes insufficient aeration of the root system and affects root development. Therefore, scientific water management is essential. Choose unpolluted river water, spring water, or well water as irrigation water for cut roses, and a drip irrigation system is preferable. The watering time, frequency, and amount for cut roses are affected by season, weather, soil, and plant growth conditions, and producers mainly determine them based on production experience or by continuously observing and testing soil moisture content and plant growth with instruments. A soil tensiometer, which quickly measures soil moisture, can be used to monitor soil moisture and serve as a reference for watering.

Fertilization Management

During the vegetative growth period, the demand of cut roses for the major elements nitrogen, phosphorus, and potassium is an N:P:K ratio of 3:1:2, and during the flowering period 3:1:3; secondary elements and trace elements can be applied regularly each month. The amount of fertilizer should be considered according to factors such as soil fertility, plant growth conditions, and yield; the fertilization method should be based on the facility conditions. In actual production, attention should be paid to increasing the application of organic fertilizer. For soil cultivation, fully decomposed organic fertilizer needs to be added once a year to ensure the soil organic fertilizer needs for cut rose growth. The total annual addition is generally 8-10 tons per mu, to supplement the decomposition of organic matter and bring soil organic matter to above 5%; the best time to add it is autumn and late winter each year. When adding organic fertilizer, dig a shallow trench 30 cm deep and 25-30 cm wide in the middle of the bed (between the rows), then add the organic fertilizer directly, and finally mix it evenly with the soil.

The cultivation period for cut roses generally lasts as long as 5 to 8 years, so sufficient base fertilizer should be applied first at planting, such as decomposed livestock manure and nitrogen, phosphorus, and potassium fertilizers. Small seedlings that have survived grafting or cutting are planted in the cultivation house at a spacing of 45 cm x 30 cm. When planting, spread the roots out in all directions, bury the graft union 3 cm below the soil surface, about 2 cm higher than the surrounding soil layer. After planting, water thoroughly around the roots and strengthen water and fertilizer management. Small seedlings have a relatively high water requirement during the vegetative growth period, so water once every 2-3 days; before the axillary buds break, control water appropriately, and from axillary bud break to new shoot growth, gradually increase the amount of watering to promote branching. From flower bud formation to the flowering period is the peak water demand of the entire growth period, so water once a day if possible. In early August and September-October, appropriate intertillage and fertilization can be carried out, applying oil residue, bone meal, chemical fertilizer, and plant ash between the plants.

In the early stage of vegetative growth of small seedlings, all flower buds should be removed promptly to help cultivate flowering mother branches and allow the branches to grow robustly. Some varieties sometimes grow 2 or 3 flower buds on the shoot tips; at this time, keep the central main bud and remove the side buds beside it, so as to avoid dispersed nutrients that affect flowering quality. Flower buds formed in the hot midsummer climate will be affected by high temperatures, developing poorly and opening prematurely, with no commercial value, so at this time remove any bud seen to promote branch development. Rose pruning can be done twice a year, autumn pruning and winter pruning. During the autumn growing period, before the flower buds have formed, the branches can be heavily pruned to a height of 60-80 cm to renew old branches, control the flowering period, and promote branch development. After entering dormancy and before sprouting the following year, winter pruning can be carried out to control plant height and shape the tree form.

The above is the complete content of the propagation and management of cut roses that I have summarized for everyone. I hope this article can help you. Please also continue to follow us.

about 2 cm higher than the surrounding soil layer. After planting, water thoroughly around the roots and strengthen water and fertilizer management. Small seedlings have a relatively high water requirement during the vegetative growth period, so water once every 2-3 days; before the axillary buds break, control water appropriately, and from axillary bud break to new shoot growth, gradually increase the amount of watering to promote branching. From flower bud formation to the flowering period is the peak water demand of the entire growth period, so water once a day if possible. In early August and September-October, appropriate intertillage and fertilization can be carried out, applying oil residue, bone meal, chemical fertilizer, and plant ash between the plants.

In the early stage of vegetative growth of small seedlings, all flower buds should be removed promptly to help cultivate flowering mother branches and allow the branches to grow robustly. Some varieties sometimes grow 2 or 3 flower buds on the shoot tips; at this time, keep the central main bud and remove the side buds beside it, so as to avoid dispersed nutrients that affect flowering quality. Flower buds formed in the hot midsummer climate will be affected by high temperatures, developing poorly and opening prematurely, with no commercial value, so at this time remove any bud seen to promote branch development. Rose pruning can be done twice a year, autumn pruning and winter pruning. During the autumn growing period, before the flower buds have formed, the branches can be heavily pruned to a height of 60-80 cm to renew old branches, control the flowering period, and promote branch development. After entering dormancy and before sprouting the following year, winter pruning can be carried out to control plant height and shape the tree form.

The above is the complete content of the propagation and management of cut roses that I have summarized for everyone. I hope this article can help you. Please also continue to follow us.