How to grow carnations best? A detailed guide to cultivation methods

Carnations belong to the genus Dianthus in the family Caryophyllaceae. Carnations include many varieties and hybrids, and in a greenhouse they can bloom almost continuously. They usually bear double flowers, with diverse and vivid colors and a fragrant scent. Carnations are one of the most popular cut flowers, representing health and good wishes, and can be used for flower arrangements, corsages, and more. Below, the editor will introduce how to grow carnations.

Growth habits of carnations

1. Light conditions: Carnations are long-day plants that prefer abundant sunlight. Apart from the seedling stage and full bloom stage, there is no need to worry about damage from strong light, and supplementary light can increase flower diameter and color vividness. Light intensity has a clear positive correlation with cut flower yield per unit area.

2. Temperature conditions: Carnations prefer cool conditions, are not tolerant of heat, and can endure a certain degree of low temperature. If the summer temperature is above 35°C or the winter temperature is below 9°C, growth becomes very slow or even stops. During high-temperature summer periods, corresponding cooling measures should be taken, while in winter plastic film cover or a greenhouse is needed to maintain appropriate temperature.

3. Moisture conditions: The carnation root system is fibrous. Long-term waterlogging in the soil or medium, excessively high humidity, or prolonged high temperatures on the leaf surface are all unfavorable to its normal growth and development. Therefore, drip irrigation is recommended, and attention should also be paid to water quality and water salinity.

4. Soil conditions: Carnations prefer soil with good fertilizer retention, aeration, and drainage, with heavy loam being the best. The suitable soil pH for their growth is 5.6-6.4. Some soil analysis experiments show that within a pH range of 5.95-7.9, soil organic matter content has no obvious effect on flowering; soil texture is the main determining factor.

Propagation methods for carnations

Carnations are mainly propagated by seeds and cuttings. The optimum germination temperature for seed sowing is 20°C, and seeds take a relatively long time to germinate, requiring 10-15 days. After sowing, it takes 140-160 days to bloom. The optimum temperature for plant growth is 5-20°C. When the temperature is above 30°C, the plants stop growing or even die. Therefore, in South China, cultivation is suitable in winter and spring. When production is intended for blooming at Spring Festival, sowing and cultivation should be carried out from August to early September in cool regions (high mountains). The potting medium for carnations requires good drainage and rich organic matter, and the cultivation environment requires abundant sunlight. If the temperature is too high or light is insufficient, plants tend to grow leggy, with slender branches, poor plant shape, and difficulty flowering.

Seedling-raising techniques for carnations

For a long time, most flower growers relied on self-propagation and self-cultivation, consistently using the method of taking middle side shoots from mother plants in flower-harvesting fields for propagation. Seedlings were reused for many generations, causing seedling quality to decline. The quality of the seedlings directly affects the growth vigor of field plants after planting and the subsequent yield and quality of fresh flowers. Therefore, during cultivation, a mother plant nursery and a cutting nursery should be established. The techniques are as follows:

1. Seedbed preparation: Carnations are fibrous-rooted plants and require loose, breathable soil conditions with good water retention and fertilizer retention for growth. The seedbed soil should preferably be peat or other media mainly composed of peat. Sufficient fertilizer should be applied into the medium, including nitrogen, phosphorus, potassium, and some trace elements. Three days before planting, water heavily to make the soil fully moist. The medium thickness should be at least 20 cm to ensure that the carnation mother plants have enough soil layer to grow roots, absorb nutrients, and grow and develop normally. Seedbeds or raised beds should be built according to the specifications of the greenhouse or plastic tunnel. The suitable height of the seedbed is 80-100 cm, and the suitable depth is 25-30 cm, not less than 20 cm.

2. Introducing mother plants: Select varieties according to market demands and the local cultivation ecological environment, introduce excellent varieties with high yield, superior quality, vigorous growth, strong disease resistance, and good stress resistance, and carefully tend them according to the characteristics of each variety. Then take healthy cuttings, root them by cutting to obtain high-quality strong seedlings, establish a cutting nursery, and produce commercial seedlings.

3. Mother plant nursery cultivation

① Rain sheltering: To ensure vigorous seedling growth, using plastic tunnels for rain-sheltered cultivation of the carnation mother plant nursery and cutting nursery is a very good measure.

② Density: Planting density has a great relationship with cutting yield. Choosing a reasonable cultivation density is beneficial both for plant ventilation and light penetration and for forming a high-yield population structure and increasing effective branching. A density of about 50 plants per sq m is generally used. When planting carnations, the principle of planting as shallowly as possible without lodging should be followed. After planting, water well and thoroughly to settle the roots, so that the root system is in full contact with the soil. If planted too deeply, stem rot is more likely to occur.

③ Field management: A large number of white roots growing from the root area indicates that the mother plants have survived. At this point, moisture should gradually be controlled to ensure a well-developed root system. Every 7-10 days, apply fertilizer once according to seedling condition, and spray an insecticide and fungicide once. When plants grow to 7 leaves and 1 heart, pinching can begin. Depending on the branching ability of different varieties, retain 5-7 pairs of leaves to allow side branches to develop later for cutting collection. Normally this is not used for seedling raising, but can be used as tissue culture material for rejuvenation and seed preservation. When side branches grow to 7 leaves and 1 heart, cutting collection can begin. Generally, retain 3-4 pairs of leaves on the mother plant, and bind cuttings in bundles of 25-30 stems with rubber bands, place them in cardboard boxes or plastic boxes, and store them in a 1-2°C cold storage for later use.