The Holy Spirit is the pruner. We need to be willing to be in God's hands. There must be a dormant or unfruitful stage. All plants have a dormant stage when the roots are getting deeper. This dormant period is a time of preparation.
Fruit only comes when it's the right season.
Sometimes we may feel we're not fruitful. God is busy watering us, and pruning us, and making sure we have plenty of nutrients and sunlight so that when the harvest season comes, we will have an abundance of fruit. The branches must abide in the vine. There are some grape varieties where they have actually grafted in branches into the vine. As long as we abide in the vine we will bear fruit.