A Detailed Guide to the Latest Cultivation Methods for Freesia

Freesia is also known as xiaocanglan, xiaochanglan, jiandaolan, and other names. It is a perennial bulbous herbaceous flower of the genus Freesia in the iris family (Iridaceae). It gets its name because its flowers are pure white as snow and its fragrance is as delicate as that of an orchid. It is cultivated mainly for ornamental purposes. In southern regions it is mostly grown in the open air, while in northern regions it is mostly grown in pots. It is commonly used as a potted plant or its flowering stems are cut and placed in vases to decorate interiors. Now let us take a look at the cultivation methods for freesia!

Growth Habits of Freesia

Freesia prefers a cool, moist environment with ample light. It has poor cold tolerance. The suitable temperature for growth is 15-20°C, and the minimum overwintering temperature is 3-5°C. A large temperature difference between day and night is beneficial for growth and development. The nighttime temperature should ideally be 10-15°C, and the daytime temperature should not exceed 20°C, otherwise growth will be poor. It prefers loose, well-drained soil rich in humus. Under short-day conditions, freesia is favorably promoted in flower bud differentiation, and after flower bud differentiation, long-day conditions can advance flowering. Typically, corms are planted in September, flower bud differentiation begins in early November and is completed by late November, and after May of the following year the leaves gradually wither and the corms enter a natural dormant period.

Propagation Methods of Freesia

1. Seed sowing: Freesia seeds are usually collected promptly after they mature in May-June, otherwise the capsules split open and the seeds are lost. The seeds have no dormancy habit and can be sown immediately after collection. The optimal temperature for seed germination is 15-20°C, and germination is uniform under dark conditions, taking about 21 days. When the seedlings have 5-7 leaves, the aboveground part turns yellow and withered, and the underground corm enters a high-temperature dormant period. After dormancy, they are planted again and cultivated for 1 year to produce daughter corms, which can then serve as flowering mother corms.

2. Division of corms: Freesia generally produces 4-6 daughter corms around the mother corm. They are dug up during the summer dormant period, and the daughter corms are separated from the mother corm and stored, then planted in autumn. For cut flower cultivation, the corms are required to have a stem circumference of over 8 cm to ensure cut flower quality. The method for cultivating daughter corms is to dig up and store the daughter corms during the summer dormant period, and by early August the daughter corms can be planted separately in flower pots.

Cultivation Methods of Freesia

1. Soil: Freesia prefers well-drained, loose and fertile sandy loam or culture soil mixed with 20%-50% humus soil. Before planting, the soil should be sterilized, which can be done with 50-70 grams per sq m of methyl bromide. After application, the soil should be turned and raked level, and planting can be done after 5-7 days. For potted culture soil, leaf mold, garden soil, fine river sand, and decomposed organic fertilizer can be mixed in equal parts of 1 part each.

2. Planting: The planting time of freesia varies depending on the production type and the market requirements for fresh flowers. The normal planting period is September-October, with the main flowering period in March-April. For forcing cultivation, it is from early to mid-September to mid to late November; for retarding cultivation, it is from January to March. The general plant and row spacing is 8*12 cm, and the planting density is 80-110 plants per sq m. The planting depth should be such that the top of the corm is 1-2 cm from the soil surface, covered with 2-3 cm of soil.

3. Fertilization: Freesia corms are relatively small and have limited stored nutrients, so phosphorus and potassium liquid fertilizer should be applied when there are 2-4 leaves. Before planting, organic compost or coarse granular organic fertilizer should be applied early to improve soil fertility, soil looseness, and aeration. The base fertilizer should be mainly organic fertilizer, and some chemical fertilizer may also be appropriately applied, but the amount should not be too much to prevent an increase in salt concentration in the soil that could cause physiological disorders. Topdressing should be mainly liquid fertilizer.

4. Watering: In the early stage after potting, freesia does not need much water. The potting soil should be kept alternately dry and moist, and watering thoroughly once a week is sufficient. By early February, when buds appear and stems are bolting, the plants grow rapidly and consume more water, so the pot should be kept constantly moist. One month after flowering, water supply should be gradually reduced, and watering once every 2 days can prevent corm rot. By late February when the leaves turn yellow and withered, watering can be stopped.

5. Temperature: Both root formation and flower bud differentiation in freesia require a relatively cool environment. Roots grow best at 15-18°C, flower bud differentiation is optimal at 12-15°C, and inflorescence growth is fastest at 18-20°C. Therefore, in the early planting stage, maintain a room temperature of 15-18°C. During the 5-7 leaf stage, induce flower primordia at 12-15°C, and maintaining this temperature for 4-6 weeks will prevent the inflorescence development from reversing. Then raise the temperature to 16-17°C to quickly extend the inflorescence and enter the flowering period.

6. Light: During freesia cultivation, appropriate shading is beneficial during the seedling stage and flowering stage. During the first leaf growth period, appropriate shading can lower soil temperature and promote root development. Before flower bud differentiation, giving a short-day treatment of about 10 hours favorably promotes flower bud differentiation and increases flower stem length as well as the number of flowers and lateral spikes on the inflorescence. After flower bud differentiation is complete, appropriately extending the photoperiod favorably promotes good inflorescence development and earlier flowering.

7. Pests and diseases: Freesia is susceptible to mosaic disease, corm rot, and other diseases. During planting, the soil and corms must be thoroughly sterilized, and the potting soil must be completely replaced every year. At the same time, attention should be paid to controlling aphids. In the early stage of aphid occurrence, 40% omethoate 1500-fold solution or 90% trichlorfon solution can be sprayed for control.