How Many Times a Year Does a Grapevine Flower and Bear Fruit, and How to Plant for Flowering and Fruiting
Grapes are a fruit tree widely grown in China. Because of their sweet taste, rich nutrition, and simple growing techniques, they are favored by many growers. However, since there are many grape varieties and the growing techniques differ, to grow grapes well you need to master the characteristics of grapes. So how many times a year does a grapevine flower? How many times does it bear fruit? How should you plant it so it flowers and fruits?
How many times a year do grapes flower? How many times do they bear fruit?
Grapes flower at least twice or more every year, and each time they can bear fruit. If the flowers open too late, the fruit they set cannot ripen. As for fruiting, it is generally 1 to 3 times, but this is related to the grape variety and the length of the growing period. Generally, mid-to-late-maturing varieties bear fruit only once a year, such as Richard Mathat, Milk, Klingbamak, Longyan, Beauty's Finger, Red Globe, and so on.
Many mid-to-early-maturing varieties can bear fruit multiple times a year, such as Jingxiu, 87-1, Pannonia, Shifurosa, Pearl of Csaba, Queen of the Vineyard, Jingya, Kangtai, Jingyou, Kyoho, Longbao, White Banana, Jixiang, Tianfeng, Fujiminori, Red Fuji, Dabao, Sunset Red, 8611, 8612, Jingzijing, Venus Seedless, Seedless White Chicken Heart, and so on. How many times a multiple-fruiting variety can bear fruit is related to the length of the growing period. In places such as Gongzhuling and Shenyang, the second crop of mid-to-early-maturing varieties can ripen, while late-maturing varieties cannot ripen; in the south, the second and third crops can ripen. It is also related to management techniques: with good management and strong tree vigor, the second and third crops grow quickly and can ripen. In a greenhouse, with proper management and strong tree vigor, varieties such as Seedless White Chicken Heart, White Banana, Tianfeng, and Venus Seedless can bear 4 to 5 crops a year, and can even achieve year-round fruiting.
Planting techniques:
1. Planting time: Open-field autumn planting of grapes tends to freeze to death, and greenhouse autumn planting is unfavorable for dormancy, so for both open field and greenhouse, spring planting is best, from January to May, after the soil thaws until after germination, but the later it is, the weaker the growth. In addition, in a greenhouse you can also plant the vines first and build the greenhouse afterward.
2. Land preparation and ridging: For both open field and greenhouse, rows run north-south, with a row spacing of 1.8-2 m, and ridges are raised along the rows. In areas where soil is mounded in winter for cold protection, make large ridges; in areas where soil is not mounded in winter for cold protection, make small ridges. Before ridging, there are two ways to prepare the land.
3. Deep plowing of the whole orchard: Spread fermented manure on the ground, usually about 5 cubic m per mu, and more than 10 cubic m per mu for a new greenhouse; old greenhouses have higher organic matter content, so manure may be omitted. Then plow deeply about 40 cm over the whole area.
4. Digging trenches along the rows: 60-80 cm deep and 80-100 cm wide. Fill the lower half with about 500 kg of weeds mixed with topsoil, and fill the upper half with about 5 cubic m per mu of organic fertilizer mixed with topsoil until full. If there is not enough topsoil, it can be dug from between the rows, and the subsoil can be spread between the rows, then settled with a heavy watering.
5. Sapling treatment: If it is a grafted seedling, cut off all the rootstock buds, keep only the grafted buds, and remove the binding film.
6. Pollinator trees: Grapes are cleistogamous, so there is no need to plant pollinator trees. Different varieties should be planted in blocks to make management easier.
7. Planting method: Along the rows, at a plant spacing of 0.7 m, plant on one side of the ridge. The planting method is as follows.
(1) In areas where soil is mounded in winter for cold protection, plant on one side of the large ridge: ① Plant grafted seedlings slanting northward, with the graft union about 10 cm above the ground, so that in the future nothing roots above the graft union and it is also easy to mound soil for cold protection. After planting, water heavily; when the soil surface looks dry, continue mounding soil over 10 cm above the graft union, and after germination remove the soil mound. ② Plant cuttings slanting northward, with the original yin-yang line about 10 cm below the ground level, so that even if the aboveground part freezes to death in the future, the underground part can still sprout. After planting, water heavily; when the soil surface looks dry, continue mounding soil over 10 cm, and after germination remove the soil mound. ③ Plant green seedlings from nutrient cups straight, but do not bury the green vine, otherwise the seedlings will rot. After planting, water heavily.
(2) In areas where soil is not mounded in winter for cold protection, plant on one side of the small ridge: ① Plant grafted seedlings slanting northward, with the graft union about 25 cm above the ground. After planting, water heavily; when the soil surface looks dry, continue mounding soil up to 10 cm above the graft union, so that the seedlings are on the large ridge, and after germination remove the soil to expose the graft union. ② Plant cuttings slanting northward, with the original yin-yang line slightly above the ground level. After planting, water heavily; when the soil surface looks dry, continue mounding soil about 25 cm, so that the seedlings are on the large ridge. ③ Plant green seedlings from nutrient cups straight, but do not bury the green vine, otherwise the seedlings will rot; gradually mound soil during the growing season, and the seedlings will also be on the large ridge.
8. Fertilizer management
Apply base fertilizer in autumn after harvesting the fruit. Along the outer edge of the original planting hole, dig 40×40cm deep holes outward and apply organic fertilizer in multiple layers, with one layer of soil and one layer of fertilizer, mainly human and livestock manure, barnyard manure, composted manure, etc. For grapes in full fruit stage, apply more than 2 kg of organic fertilizer per 1 kg of fruit produced. Topdressing is mainly in 2 periods: apply 1 time of quick-acting fertilizer such as decomposed human manure and urine more than ten days before flowering. During the fruit expansion period, apply 1 time of fertilizer mainly based on potassium fertilizer, such as plant ash or decomposed chicken manure, etc.