Cultivation and Cut Flower Production of Freesia
A comprehensive guide to the experience of growing Freesia at home, including its cultivation and cut flower production. Detailed introduction is as follows:
Freesia (Fressia hybrida Klatt.) also known as Little Freesia, Little Iris, Scissors Orchid, Plain Fragrant Orchid, Fragrant Iris, and Foreign Night Fragrant Narcissus, belongs to the genus Freesia in the family Iridaceae. It is a perennial bulbous herbaceous flower native to the Cape of Good Hope in southern Africa. There are currently about 20 species, which are commonly cultivated into red, yellow, white, blue, and other color series based on flower color. Due to its early blooming period, bright color, fragrant flowers, and long vase life, it can be sold in early spring and during the Spring Festival (G-Y). It can be cultivated as a cut flower or potted plant in a greenhouse, and is highly favored by flower enthusiasts.
1 Morphological Characteristics and Habits
It is an autumn planted bulbous flower that blooms in winter and spring and enters dormancy in summer. After planting the bulbs, the terminal buds of the underground corms sprout into plants, and some varieties can also sprout into plants from the first lateral buds below the terminal bud. Each plant has 6 to 10 basal leaves arranged in two rows. The leaves are linear and sword-shaped, entire, 15 to 30 cm long, and 0.5 to 0.7 cm wide. The flower stems are usually single or branched, 30 to 45 cm tall, with short stem leaves. The flower stems are erect, with terminal spikes, and the floral axis is nearly perpendicular. The flowers are funnel-shaped, with 2 to 10 flowers per inflorescence, flowers are borne on the upper side, upright, and bloom from bottom to top. The flowers come in white, yellow, pink, peach, rose, purple, snow blue, blue-violet, and other colors, as well as bicolors, rich in color, fragrant, and there are large-flowered tetraploid varieties and double-flowered varieties. The natural blooming period is from February to May, after which it produces capsules, with fruit maturity in June to July and seeds that are brown and black. The underground corm is a modified short stem, conical or oval in shape, with the outer part of the leaf sheath drying into a brown fibrous skin, and the diameter of the corm is 1 to 5 cm. Generally, mature corms have 4 nodes, each with an axillary bud. There are two types of root systems, the fibrous roots from the bulb base are the main absorbing roots, and when the new bulbs form, the new roots from the base of the new bulbs have a牵引 effect on the new bulbs, hence called traction roots.
Freesia prefers a cool and humid environment with sufficient light, has poor cold resistance, and the optimal growth temperature is 15 to 20°C, with the minimum winter temperature being 3 to 5°C. A temperature of 13.5 to 15°C can promote root and bud formation. Flower bud differentiation requires a low temperature of 8 to 13°C, and the development period requires a suitable temperature of 13 to 18°C. Temperatures below 18°C will delay flowering and shorten the flower stem. Higher temperatures can promote early flowering but may weaken plant growth. Short-day conditions are favorable for flower bud differentiation, while after differentiation, long-day conditions can promote early flowering. Corms are usually planted in September, with flower bud differentiation starting around the first ten days of November and completion by the end of November. The plants enter a natural dormancy period after May of the following year.
2 Cultivation Management Essentials
Conventional cultivation mainly involves dividing small bulbs in autumn for flowering in early spring (G-Y) the following year. Freesia is not cold-resistant and mainly relies on protected cultivation facilities.
2.1 Soil Preparation Freesia prefers a sandy loam soil rich in organic matter, with good water retention and drainage, and a pH of 6 to 7.2. Soil disinfection can be done before planting using pentachloronitrobenzene at 6 to 10g per square meter, methyl bromide at 50 to 70g, and carbaryl at 8 to 12g. After applying the chemicals, turn and level the soil, and planting can begin after 5 to 7 days. The ridge height of the planting bed is about 5cm in dry areas and 20 to 25cm in areas with high soil moisture and poor drainage.
2.2 Corm Preparation Freesia corms have a long natural dormancy period of about 50 to 60 days. After digging up the corms, they are stored at 28 to 31°C for 2 to 3 months to germinate, while at a low temperature of 13°C, dormancy can last up to 8 months. Therefore, breaking dormancy through high-temperature followed by low-temperature treatment is required before planting Freesia.
(1) Corm Selection Cultivation corms should be selected with a diameter of 1cm or more. To reduce virus infection, it is necessary to choose virus-free tissue culture corms or new corms grown from seeds or daughter bulbs. Generally, tissue culture seedlings or seed sowing are used, and the small bulbs can be cultivated into high-quality corms after 1 to 2 years.
(2) Corm Pre-treatment Before planting, corms need to undergo pre-treatments such as disinfection, breaking dormancy, and promoting root growth. Corm disinfection can be done by soaking the corms in a 500 to 800-fold solution of fungicides such as carbendazim or thiophanate-methyl for 1 to 2 hours, then drying in the shade. Root promotion should be done when roots start to grow, and the roots should not be too long to avoid damaging them during planting.
2.3 Planting The general planting period is from September to October, with protected facilities for overwintering and the main flowering period in March to April. By properly spacing the planting and adopting early and delayed cultivation methods, Freesia can be supplied throughout the year. The planting distance varies with the variety, size of the corm, and cultivation season. Generally, the plant spacing is 8cm x (10 to 14)cm, with a planting density of 80 to 110 plants per square meter. Narrow-leafed varieties are planted denser than broad-leafed ones, winter cultivation is denser than summer, and small bulbs are planted denser than large ones. When planting, usually cover the soil with 2 to 3cm, avoid too thick, and after planting, cover the soil surface with a thin layer of peat, pine needles, straw, or sawdust to keep the soil moist.
2.4 Fertilization and Water Management The soil must be kept moist from planting to emergence. After the buds appear, reduce the watering gradually to keep the soil surface dry, which helps to lower the humidity and prevent diseases. Since the time from planting to flowering is short, the organic and compound fertilizers applied before planting can basically meet the growth needs. However, if the plants grow weakly, a top dressing of ammonium nitrate, urea, and potassium sulfate can be applied when 2 to 4 leaves are present. Apply a 0.2% phosphorus acid potassium spray at the initial flowering stage, but avoid top dressing before and after bud formation.
2.5 Temperature Management Temperature management is very important for Freesia cut flower production. About 6 weeks after planting, the inflorescence is fully differentiated, while smaller corms may be delayed by 2 to 3 weeks. During the flower bud differentiation period, avoid high temperatures above 25°C and low temperatures below 10°C. Ensure that there are more than 4 weeks of temperatures between 13 to 14°C from the 4-leaf stage to promote the differentiation of flower primordia during the 4 to 6-leaf stage, which is beneficial for increasing cut flower yield and quality. After the flower buds appear, slightly increase the environmental temperature to promote flowering; however, to extend the flowering period, after the first flower opens, the temperature can be lowered to about 15°C to extend the harvest period. Greenhouse and greenhouse management should ensure ventilation when the room temperature exceeds 25°C and cover insulation or heating when the temperature is below 10°C.
2.6 Light Management During the seedling stage and flowering stage, it is appropriate to provide some shading. In the first leaf growth stage, shading can reduce ground temperature and promote root development. Short-day treatment of about 10 hours before flower bud differentiation can promote bud differentiation, increase flower stem length, and the number of flowers and side spikes on the inflorescence. After flower bud differentiation, extending the day length can promote good development of the inflorescence and early flowering. Although Freesia prefers light, it should be protected from strong sunlight. In strong light and high temperatures, a shading net with a light transmission rate of 70% can be used.
2.7 Netting Freesia flower branches are soft, and the inflorescence grows bendingly, making it prone to drooping and falling when there are many flowers. When the plants have 3 to 4 leaves, start setting up支架 and netting, with the first layer of netting about 25cm from the ground, and add 2 to 3 more layers as the plants grow. The grid of the netting is usually 10cm x 10cm or 10cm x 15cm.
2.8 Cut Flower Harvesting The appropriate time for harvesting is when the first small flower on the main flower branch opens. For long-distance transportation or storage, cut when the first small flower shows color or is half-open. The cutting tool should be disinfected with alcohol to prevent the spread of diseases. The cutting position is usually at the base of the main flower branch to allow the side flowers below to continue for the second or third harvest. The commercial cut flower stem length should be over 55cm. If the inflorescence is small and the stem is too short, affecting the quality of the product, the main stem and side branches can be cut together and then the side branches removed. After cutting, the flowers are bundled by variety and quality, with 10 or 20 stems per bundle, the flower parts wrapped in paper, and placed in preservative solution or water. They can be stored fresh for 7 days at 1 to 2°C and 90% relative humidity, and packaged in cartons for transportation, with 300 to 500 stems per carton. For the last cut, leave at least 2 leaves to promote the development of the underground corm, usually after the leaves turn yellow.
The above introduction to the cultivation and cut flower production of Freesia is for reference by netizens.