Evie Smith, UCCE Staff Research Associate, Southern Sacramento Valley
Katherine Jarvis-Shean, UCCE Orchard Advisor, Sacramento, Solano and Yolo Counties
Franz Niederholzer, UCCE Farm Advisor, Colusa and Sutter/Yuba Counties

Please note that the following are general recommendations intended to help you keep track of regular practices in a busy time; the optimal timing for management practices may vary based on specific location and conditions.

• Weed survey: After the first rain, scout for weeds in your orchard to inform your weed management strategy for next season. For more information about best practices for weed scouting, see our article on post-harvest weed scouting. The Weed Research and Information Center Weed Identification Tool can help you ID the weeds in your orchard. If we have another dry fall, consider watering in your pre-emergent herbicide with irrigation to ensure efficacy.
• Fall Nutrient Spray: If your July leaf samples indicated that your trees are low on Zn or hull samples show them low on B, apply these nutrients through a foliar spray in the fall. Fall spray timing ensures these nutrients will be available to the trees when they wake up in February. See our article on postharvest nutrition for more information.
• Irrigation Water Quality: If your irrigation water was of lower quality this season, take soil samples to assess the build-up of salinity and toxic element(s) such as chloride, boron and sodium. See video series on soil sampling from the UC Davis Fruit and Nut Center. Consult with your CCA regarding fall irrigation practices to help manage rootzone salinity if elevated levels are found.
• Shot Hole: If shot hole fruiting structures are present in leaf lesions in the fall, the likelihood that shot hole will develop in the orchard the following spring is higher. Keep an eye out for shot hole fruiting structures in your orchard after fall rains begin. If fruiting structures are present, apply a foliar zinc sulfate nutritional spray in early November; this will speed up fall leaf drop and reduce inoculum.
• Rust: If rust was a problem in your orchard this year, consider a foliar zinc sulfate fertilizer spray in late October or early November to hasten fall leaf drop and reduce rust carry over to next season.
• Cover Crops: Cover crops can improve the soil in your orchard, reduce runoff, and provide additional pollen to bees in the spring. If you’re planning on growing a cover crop this winter, get your seed in the ground by the end of October. Supplemental irrigation may be required for germination and optimal growth if we have another dry fall and winter, so make sure you have an available water source to meet this possible need before seeding. For more information about using cover crops in almond orchards, see the Cover Crops Best Management Practices guide featured in this publication.
• Mummy Nuts: Survey for mummy nuts before or on January 15 by counting mummies in 20 trees in each orchard. Make sure all varieties in the orchard are included in the 20 trees. If there are more than 2 mummy nuts per tree, on average across the orchard, plan on sanitizing your orchard by shaking or poling nuts to the ground by February 1 and destroying the nuts before March 1st. This will reduce navel orangeworm pressure in your orchard next season.
  • If a significant number of your mummy nuts are caused by hull rot, plan on reevaluating your irrigation and nitrogen management practices in the spring of next year to help manage hull rot. For more information about how to identify hull rot in your orchard, see UC IPM.
• Pruning: This fall and winter as you are pruning out damaged branches in your orchard, make sure to avoid pruning immediately before a rainfall event. Pruning just before rain spreads diseases more rapidly in the orchard. Consider applying Topsin-M to pruning wounds to protect against canker pathogens such as Cytospora and Botryosphaeriaceae (“Bot”).