Photo: Annie Klodd In Season 3, episode 7 of What's Killing My Kale, Annie talked to Dr. Amaya Atucha, an assistant professor and Fruit Crop Extension Specialist at University of Wisconsin-Madison, about what apple growers should do in the next few weeks to maintain good fertility and fruit set on their apple trees. We also discussed the best ways to add organic matter to an orchard, and when those nutrients will become available. Topics: Applying boron and zinc, and N-P-K Why boron and zinc are important for fruit set When to start applying foliar calcium How to decide between foliar and soil application of various nutrients How best to use compost and bark mulch in the orchard Preventing herbicide injury to fruit tree trunks Click here to download and listen to the episode directly. You can also listen to all of our episodes on Apple Podcasts.