When to Plant Raisin Grapes
As a vine plant with both ornamental and medicinal values, raisin grapes have been popular in the home gardening community in recent years. This unique fruit, native to tropical regions, contains knowledge in every step from seeding to harvest, and mastering the correct planting time is the key to a bountiful harvest.
Best Sowing Time under the Differences between North and South
Consideration of Temperature and Region
When the temperature stabilizes between 20-28℃, it is the golden period to awaken the raisin grape seeds. It is recommended to start seedling raising in the first ten days of March in the south of the Yangtze River, and with the help of a small arch shed for insulation, it can be advanced to the last ten days of February. In the Yellow River Basin, sowing should be done around Qingming (April 5-15). In the northeast region, it is recommended to start greenhouse seedling raising in early May.
Scientific Basis of Accumulated Temperature Calculation
Raisin grape seeds need to accumulate effective temperature of ≥10℃ up to 120℃·day to germinate, calculated at an average daily temperature of 25℃, it takes about 5 days to complete germination. Sowing too early will lead to an extended dormancy period of the seeds, and sowing too late will affect the subsequent flowering and fruit-setting cycle.
Full Process Management from Seed to Harvest
Three Steps of Seed Pretreatment
1. Select plump seeds and soak them in 45℃ warm water, let them cool naturally for 8 hours. 2. Wrap them in damp gauze and place them in a constant temperature device such as a router (30±2℃). 3. Sow immediately when the radicle breaks through the seed coat by 1mm.
Golden Formula for Soil Mixture
Use a matrix formula of humus soil: river sand: vermiculite = 5:3:2, add 5kg of decomposed sheep manure and 2kg of bone meal per cubic meter. Keep the pH value between 6.0-6.8, and maintain a sowing depth of 2-3cm.
Key Points Control of Growth Cycle
Seedling Management Tips
After the seedlings emerge, apply a diluted solution of seaweed extract (1000 times) every week, and pinch the top for the first time when the true leaves unfold. When the vines grow to 30cm, build a 2m high mesh shelf and use the figure-eight method to tie the branches.
Flowering and Fruiting Period Control Techniques
During the bud formation stage, spray 0.2% borax solution on the leaves, combined with a day-night temperature difference of 10℃ (28℃ during the day and 18℃ at night) to increase the fruit-setting rate by 40%. During the fruit color transformation stage, maintain soil moisture content at 60%-70% to effectively prevent fruit cracking.
After mastering these planting tips, it takes about 110-130 days from sowing to harvest. Remember to make the last harvest 15 days before the first frost, leave enough seed fruit, and clear the vines in time for the next year's harvest.