After a seemingly never ending winter, spring is finally in the air. Hopefully, your vines are all pruned and ready to go for the season. This time of year, the vines are patiently waiting between two important stages: winter pruning and shoot thinning. But don’t let that keep you out of the vineyard! Here are a few things you can do to get ready for the upcoming season:
By Diana Cochran
Cluster thinning. A balance between plant vigor and fruit production. Many of the grape cultivars grown in Iowa tend to overproduce fruit, which can reduce berry size and cause non-uniform ripening. If you have noticed smaller berries, non-uniform ripening, or an unbalanced sugar:acid ratio, you should consider cluster thinning. Cluster thinning should begin after fruit set (berry diameter between 1/16 and 1/8 inch) and before veraison.