Understanding the distinct seasonal needs of jasmine plants is crucial for their health and prolific blooming. From a botanical perspective, the care regimen shifts dramatically between the active growing season and the dormant period to align with the plant's natural physiological cycles.
During the summer, jasmine is in its peak growth and flowering phase. Its metabolic rate is high, and transpiration through the leaves is rapid, especially in warm, sunny conditions. The plant requires consistently moist soil to support this vigorous activity. Allowing the soil to dry out completely can lead to bud drop, wilted leaves, and stunted growth. In contrast, winter marks a period of dormancy for most jasmine varieties. The plant's growth nearly halts, and its water requirements diminish significantly. The goal shifts from supporting growth to preventing root rot in cool, damp soil. The top few inches of soil should be allowed to dry out thoroughly between waterings. Overwatering in winter is a far greater threat than underwatering, as the roots are not actively taking up moisture and are susceptible to fungal diseases.
Summer light is intense, and jasmine plants are sun-worshippers during this time. They require several hours of direct sunlight daily to produce the energy needed for flowering. A south or west-facing location is ideal. However, in extremely hot climates, some protection from the scorching afternoon sun can prevent leaf scorch. In winter, the sun's angle is lower, and the light is less intense. While the plant is dormant, it still requires bright, indirect light to maintain its health. A sunny windowsill is perfect. This light exposure helps to harden off the new growth from the previous season and provides the minimal energy required to sustain the plant until spring, even if it drops some leaves, which is a normal conservation strategy.
Jasmine thrives in the warmth of summer. Most common varieties, like Jasminum officinale, prefer temperatures between 60-75°F (15-24°C). They are actively photosynthesizing and respiring, using the warmth to fuel their processes. The primary summer concern is sudden heatwaves, which can cause stress. Winter care is dominated by temperature management. Many jasmines are not frost-hardy. Exposure to freezing temperatures can cause cell damage, as the water within the plant's tissues freezes and expands, rupturing cell walls. For outdoor plants in marginal climates, this means providing mulch for root protection. For potted plants, it means moving them to a cool but frost-free location, ideally between 40-50°F (5-10°C). This cool period is essential for initiating dormancy and setting buds for the next season's bloom.
The summer is the jasmine's "feasting" season. It is a heavy feeder when in active growth. A balanced, water-soluble fertilizer or one high in potassium (to promote blooming) should be applied every two to four weeks. This provides the essential macronutrients (Nitrogen, Phosphorus, Potassium) and micronutrients needed to produce its fragrant flowers and lush foliage. In winter, fertilization must cease completely. The plant is not growing and cannot utilize the nutrients. Applying fertilizer during dormancy leads to a toxic buildup of salts in the soil, which can damage the delicate root system and potentially "burn" the roots, causing severe stress or death to the plant.
