A Detailed Guide to Gladiolus Cultivation Techniques: Key Points for Planting and Management
GladiolusThe flowers are rich in color and brilliant, and the spike-shaped inflorescence is relatively long, opening gradually from bottom to top, giving it a unique role that other cut flower types cannot provide; moreover, it lasts a long time in the vase and is easy to transport, making it one of the world's four famous cut flowers.
I. Characteristics and Traits
Gladiolus, also known as sword lily and gladiolus, is a perennial bulbous flower of the genus Gladiolus in the family Iridaceae. The plant height is 80-170 cm, and the corm is flat-round or oval, with ring-like nodes. It has 6-9 leaves, which are sword-shaped. The scorpioid umbel bears 8-24 flowers, and the blooms are large. Gladiolus prefers cool conditions, is not cold-tolerant, and fears intense heat. It requires loose, fertile, moist, and well-drained soil. The optimum temperature for growth is 20-25°C during the day and 10-15°C at night. Gladiolus is a long-day plant, and 16 hours of light per day is most suitable.
II. Gladiolus Varieties
Gladiolus is a multi-origin, multi-generation hybrid, and so far there is no universally recognized unified species name. There are many classification methods for gladiolus: by flowering period, it can be divided into spring-flowering types and summer-flowering types; by flower arrangement form, it can be divided into regular types and irregular types; by flower size, it can be divided into giant-flowered types, medium-flowered types, and small-flowered types; by flower shape, it can be divided into trumpet type, lotus type, swallow type, and so on.
III. Cultivation and Management
(1) In production, corms are mainly used for planting. In spring, grade the corms by size, soak them for 30 minutes in a 800-fold dilution of 70% thiophanate-methyl wettable powder or a mixture of a 1000-fold dilution of carbendazim and a 1500-fold dilution of captan, then sprout them at 20-25°C, and they can be planted in about 1 week. For varieties with severe virus infection and obvious degeneration, shoot-tip virus elimination can be used to rejuvenate the plants.
(2) Conventional gladiolus cultivation refers to cultivation under natural conditions, generally selecting seed corms with a diameter of more than 2.5 cm. There are two planting methods: ridge planting and bed planting, with a planting depth of 5-10 cm. When gladiolus produces its 2nd leaf, it is exactly the time of flower bud differentiation, and it is particularly sensitive to environmental factors. If it encounters low temperature and weak light, the number of "blind flowers" increases.
Generally, when preparing the soil, apply 6-9 kg of nitrogen, 6-12 kg of phosphorus, and 7-12 kg of potassium per mu. During the entire growing season, topdressing is needed 3 times, namely when 2-3 leaves have emerged, when the inflorescence emerges from the leaves, and 15 days after flowering.
(3) For forcing cultivation of gladiolus, the dormancy of the corms must first be broken. After the corms are harvested, under natural conditions, dormancy can only be broken after the low-temperature influence from late autumn to early winter. For forcing cultivation, dormancy must be broken artificially, that is, after the corms are harvested, first treat them at a high temperature of 35°C for 15-20 days, then treat them at a low temperature of 2-3°C for 20 days, and then plant them, after which they can germinate and grow normally.
If flowers are required from January to February, plant in October to November; if planted in December, they will bloom from March to May. That is, from planting to flowering takes 100-120 days. For forcing cultivation, the plant and row spacing is 15 cm × 15 cm or 25 cm × 7 cm, with 40-60 corms planted per square meter. After planting, the daytime temperature should be maintained at 20-25°C, and around 15°C at night.
(4) Gladiolus can also be cultivated with delayed cultivation. After harvest, the corms are stored in a dry cold room at 3-5°C, and then planted again in a greenhouse in July to August of the following year. The management work is the same as for forcing cultivation.
(5) The main diseases of gladiolus are:
1. Penicillium rot
During harvest and transport, try not to injure the corms; before planting, soak them in a 2% potassium permanganate solution for 1 hour; during growth, remove diseased plants at any time.
2. Dry rot
When planting, select disease-free mother corms, and during growth, remove diseased plants promptly.
3. "Blind flowers"
This is a physiological disease, mostly occurring in protected cultivation in winter. The preventive method is to ensure suitable temperature and light, and select varieties tolerant to low temperature and short-day conditions.
The main pest is the two-line slug, which can be killed by spraying with lime water or ammonia water; spread lime powder around the garden to prevent them from entering; and manually capture and kill them.
(6) Cut flowers can be harvested 60-100 days after planting, with the specific time depending on the variety. The suitable harvest time is when 1-5 florets on the lower part of the inflorescence show color. Generally, they are harvested together with 2-3 leaves, taking care not to damage the leaves left on the lower stem so that they can continue to supply nutrients to the new corms and cormels. The harvested flower stems should be graded, packaged, stored in a storage room at about 4°C, and delivered to consumers within 3-7 days. If storage or transport time is too long, quality will decline.