May 18, 2021
After more than a year of SIP-ing (sheltering in place) while sipping, there is a sense of joy and relief to finally get out and experience the freedoms that were previously taken for granted. Nothing can stop me during the spring, from from soaking in the sights and smells of the new vintage – not even my allergies. The above picture captures that brief, often overlooked crucial time in the vineyard known as bloom. These understated “fuzzies” are actually hundreds of tiny flowers which will become grapes. Each variety of grape gives off a different scent but being highly allergic to grape pollen, it’s all a sneezy, weezy, odiferous trigger for me. Bloom usually occurs from 6 to 8 weeks after budbreak. The bloom period can be quite a nail-biting time since conditions must be ideal for optimal fruit set with an average daily temperature range of 59-68F. Rain and wind can interfere with germination of the pollen grain which results in shatter. Given all curve balls that Mother Nature can and does throw in this short 3-4 week window it’s remarkable how these resilient vines manage to produce so many viable clusters.
Did you ever wonder what a grape flower really looks like? Do not underestimate this diminutive self-pollinating, self-fertile powerhouse that is highly equipped to survive and thrive. A more detailed look at grape flowers shows the complicated structure of these fascinating plants. Vitis Vinifera, the most widely planted species of wine grapes, is a hermaphrodite – it is a complete flower with both male and female on the same plant. This leads to the curious question about the purpose of the pungent pollen odor since grapevines are mostly self- pollinated. It is believed that the fragrance serves as a deterrent to protect the male reproductive tissues from predatory insects. I am always in awe of nature’s mysterious evolutionary tools but since I am not a predatory insect, I will continue to enjoy the fleeting stage of flowering grape vines along with a lot of sneezing, sniffling and watery eyes.
- The illustration is from the UC Davis online Viticulture Course. Dr. Andrew Walker’s Lesson 2—Plant Materials.