Garlic Sprout Greenhouse Cultivation Methods and Technical Key Points

Garlic sprouts, also called green garlic (when not exposed to light, they are garlic yellow). The flower scape of garlic consists of two parts: the flower stalk (scape stem) and the spathe (scape bract). The spathe is the bract at the top of the garlic flower stalk, containing an underdeveloped inflorescence. Good-quality garlic sprouts should be tender, with a plant height of about 35 cm, fresh green leaves that are neither yellow nor rotting, white fibrous roots that are not withered, and a relatively strong pungent flavor.

Morphology of Garlic Sprouts

Garlic is a perennial herb with a strong garlic odor. The bulb is large, with 6-10 cloves, covered with a grayish-white or light purple membranous tunic. The leaves are basal, solid, flat, linear-lanceolate, about 2.5 cm wide, with a sheath-like base. The flower stalk is erect, about 60 cm tall; the spathe has a long beak, 7-10 cm long; the umbel is small and dense, with 1-3 bracts, 8-10 cm long, membranous, light green; the flowers are small, often mixed with pale red bulbils about 4 mm long, or completely without bulbils; the pedicels are slender, longer than the flowers; the perianth has 6 segments, pink, elliptic-lanceolate; there are 6 stamens, white, with protruding anthers; there is 1 pistil, with a protruding style, white, and a superior ovary that is long elliptic-ovate, concave at the tip, and 3-locular. The capsule dehisces in 1 locule. The seeds are black. The flowering period is summer.

How are garlic sprouts cultivated in a greenhouse?

1. Environmental Selection:

The greenhouse should be built in a place with no pollution sources within 3 km and good environmental conditions, and the air, irrigation water, and soil must meet the quality standards for pollution-free agricultural product production.

2. Variety Selection:

For seed garlic, it is best to choose varieties with large bulbs and many cloves. You can choose Shandong white-skinned garlic and Acheng, Heilongjiang purple-skinned garlic. These two varieties have high yield, good quality, and relatively strong disease resistance.

3. Land Preparation, Fertilization, and Cultivation Time:

Prepare the land before planting garlic. Apply 10-15 kg of decomposed organic fertilizer per sq m, with a thickness of about 15 cm, and rake the bed soil level. For convenient management, make beds 150-200 cm wide and leave paths 15-20 cm wide. Greenhouse garlic sprouts can be cultivated throughout autumn and winter, but generally garlic is planted starting in late November, and the first cutting of garlic sprouts is made before New Year's Day, with the second cutting before the Spring Festival, or the first cutting of garlic sprouts is made before the Spring Festival. Garlic can also be planted in stages, focusing on supplying the market demand for New Year's Day and the Spring Festival.

4. Garlic Planting Techniques:

1) Garlic selection. Choose garlic bulbs with dry cloves, normal stem plate growth, no frost damage and no softening or yellowing, a diameter of 4-5 cm, uniform size, and white and firm texture as seed garlic. The garlic bulbs should be selected and graded by size; plant small garlic bulbs first, and plant storage-tolerant large garlic bulbs later. If planting garlic at the same time, after grading, plant them separately in different beds or different parts of the cultivation bed so that seedlings emerge uniformly.

2) Seed garlic treatment.

1. Soaking garlic. Place the selected garlic bulbs in a vat of clean water and soak for 12-14 hours. After soaking, the garlic skin should feel soft to the touch. Remove the soaked garlic bulbs and place them on a screen to drain for 7 hours before hollowing out the garlic.

2. Hollowing out the garlic. Remove the root plate from the garlic bulbs and pull out the garlic scape stem from inside the bulbs. When hollowing out the garlic, you can use a flat awl or a long nail with a flattened head, insert it into the garlic roots and pry forcefully, and the root plate and scape stem will come out, and the garlic bulb will not fall apart. Hollowing out the garlic can make the garlic sprout earlier.

3. Planting garlic. Plant the treated garlic bulbs tightly on the greenhouse cultivation bed. Before arranging the garlic, level the bed soil and press it flat with a wooden board. Before arranging the garlic, the soil should be sunned to raise the soil temperature, so it is best to arrange the garlic in the afternoon. When arranging the garlic, place the seed garlic one by one in order, as tightly as possible, and keep the tops of the garlic cloves level. The gaps between the garlic bulbs can be filled with garlic cloves. Use 15-17.5 kg of seed garlic per sq m. If the cultivation bed soil is relatively dry, water thoroughly after planting; if the bed soil is relatively moist, sun it for 1 day, water the next day, and then cover with yellow sandy soil 3-5 cm deep. The garlic sprouts grown this way are tender green, have long white stems, and are of good quality. To make full use of the greenhouse, two cultivation beds can be built.

4. Watering and applying sandy soil. Watering should be flexibly controlled according to the soil moisture content and the growth of the garlic sprouts. Because garlic sprout growth mainly consumes its own nutrients, the amount of water should not be too large, to prevent root rot. Generally, water 3 times: the first time after planting garlic, water heavily; the second time when the garlic sprouts have emerged uniformly and grown to 10 cm, water moderately; the third time 3-4 days before harvest. Note that the amount of water each time should decrease in turn, with an appropriate amount. If the tips of the garlic sprouts are found to be curling and the leaves yellowing, it indicates a lack of water, and local supplemental watering is needed, but the amount of water should not be too large. For garlic sprouts cultivated on the second layer, because the space temperature causes faster water evaporation, the number of waterings can be slightly more. In order to increase the length of the white portion of the garlic sprouts, improve quality, and reduce water evaporation, after watering, soil can be banked 2-3 times, 3-7 cm thick, and the soil used for banking should be sieved and sun-dried fine sandy soil.

5. Temperature management. After planting, maintain a slightly higher indoor temperature to facilitate garlic sprouting and garlic sprout growth. On sunny days, maintain the temperature at 25°C-27°C; on cloudy days, maintain it at 14°C-15°C; before harvesting the garlic sprouts, lower the temperature to 10°C-20°C. If the temperature is too high, the garlic sprouts grow quickly, the leaf fibers are fine and yellow-green, and in severe cases the leaves lose water and wilt, resulting in poor quality, low yield, and an impact on the second-cutting yield; if the greenhouse temperature is lower than 15°C-18°C, the garlic sprouts grow slowly, affecting yield. In winter greenhouse cultivation of garlic sprouts, the main focus is heat preservation.

6. Cutting garlic sprouts. Under suitable temperature management, greenhouse garlic sprouts can be harvested for the first cutting after 20-30 days, when they reach 30-35 cm tall. After the first cutting, after more than 20 days, when the garlic sprouts reach 30 cm tall, cut the second time. For each kg of seed garlic, two cuttings can produce 1-1.2 kg of garlic sprouts. When cutting the first time, cut at 0.5 cm above the top of the garlic bulbs to avoid affecting the growth of the next batch of garlic sprouts. After the first cutting of garlic sprouts, wait 1-2 days for new shoots to emerge before watering, so that the wound heals and rot is prevented. It is best to cut garlic sprouts in the morning; cutting in the morning gives higher yield and better quality, and facilitates timely supply to the market.