California Beekeeping Calendar: Month-by-Month Hive Tasks
California's mild winters shift the entire beekeeping calendar earlier than cold-climate guides suggest. According to the University of California's Master Beekeeper Program, colonies here begin building up as early as January, swarm season peaks in February through April, the main nectar flow runs spring into early summer, and mite treatment happens in late summer after honey is off. Bees often fly year round, so there is no true dormant season the way there is in the Midwest or Northeast.
That difference is the whole point of a California-specific calendar. If you follow a national or East Coast schedule, you will be checking for swarm cells a month too late and treating mites after the damage is done. The rhythm below is written for Santa Cruz County and similar Central Coast and inland California conditions. Adjust a few weeks earlier in warm inland valleys and a few weeks later in cool, foggy coastal pockets.
What Beekeeping Tasks Happen in January and February?
In much of California, the new season starts in winter. Manzanita blooms as early as January, and early ceanothus and mustard follow, so colonies begin rearing brood and building population while cold-climate hives are still clustered and idle.
January: Keep disturbance minimal but heft the hive to judge stored food. On a warm, calm day above roughly 55 to 60 degrees, you can do a quick check for a laying queen and food stores. Provide emergency feed only if the hive feels dangerously light. This is a good month to clean and repair spare equipment and reserve replacement bees, which sell out early.
February: Buildup accelerates. Do your first real inspection on a warm day, confirm the queen is laying, and assess space. This is when swarm preparations can begin in strong colonies. Start planning your mite management for the year. According to the UC Statewide IPM Program, monitoring should be a monthly habit through the active season.
When Is Swarm Season in California?
Swarm season on the Central Coast runs roughly February through April, earlier than most of the country. A colony swarms when it feels crowded and conditions are good, sending off the old queen with about half the bees to start a new home. It is natural reproduction, but it costs you bees and honey.
March: The colony is expanding fast. Inspect every week to ten days for queen cells (peanut-shaped cells hanging off the comb), and give the bees room by adding a box before they feel packed. This is also prime install time for new package bees and nucs, as covered in the First-Year Beekeeping in California Timeline.
April: Swarm pressure peaks. Keep inspecting for queen cells and add supers ahead of the nectar flow so the colony has somewhere to store incoming nectar. If you find swarm cells, you can split the colony to prevent the swarm and grow your apiary. Do a spring mite check now, before honey supers are full, so you have a treatment window if needed.
How Do You Manage the Spring and Early Summer Nectar Flow?
Late spring into early summer is the main honey flow across most of California, when blackberry, sage, buckwheat, and countless garden and wild plants bloom at once. This is when a strong colony brings in surplus honey.
May: Supering season. Add honey supers ahead of the bees so they are never crowded, which also helps reduce swarming. Keep monitoring for late swarm attempts. The colony should be at or near peak population. If you want a bigger honey crop, giving space now is the lever that matters most.
June: The flow often winds down as the landscape starts to dry. Watch your supers and keep adding space while nectar is still coming. Toward the end of the month, start thinking about harvest timing. Remember that any mite treatment that could contaminate honey has to wait until supers come off. For the plants driving this flow, see The Best Bee-Friendly Plants for California Gardens by Season.
What Do You Do During the Summer Dearth?
By mid to late summer, much of California browns out and natural forage becomes scarce. This summer dearth is a defining feature of our Mediterranean climate and it changes how you manage the hive.
July: Harvest honey once the flow is clearly over and frames are capped. Full harvest details are in Harvesting Honey for the First Time. After supers are off, do a mite count. Populations are climbing now relative to a shrinking bee population. During dearth, reduce entrances to help colonies defend against robbing, and make sure bees have water in the heat.
August: This is the critical mite month. According to the UC Statewide IPM Program, the treatment threshold drops in late summer because the colony is now raising the long-lived winter bees that must be as mite-free as possible. Do an alcohol wash, and if you are over threshold (commonly 2 to 3 mites per 100 bees, lower heading into fall), treat with an appropriate product following label directions. Choose a treatment suited to your temperatures, since summer heat limits some options.
How Do You Prepare California Hives for Fall and Winter?
Fall is preparation season. The colony is contracting, and your job is to send it into winter healthy, low on mites, and adequately provisioned.
September: Confirm your mite treatment worked with a follow-up count. Assess stores and the queen's laying. Combine any weak colonies rather than trying to overwinter a failing one. Keep entrances reduced against robbing, which stays intense during dearth.
October and November: Fall forage like coyote brush and late buckwheat can give a small boost. Make sure each colony has enough stored honey for winter. In California's mild climate, general guidance is to leave roughly 30 to 50 pounds rather than the 60 to 90 pounds cold-climate keepers aim for, because colonies here burn less fuel and often forage on warm days. Do a late oxalic acid treatment during a broodless window if your program calls for it. Winterize by ensuring good ventilation and dry conditions, since damp is a bigger coastal threat than cold.
December: The quiet month. Leave the bees alone, heft hives to monitor weight, and provide emergency feed only if a hive is alarmingly light. Use the downtime to clean equipment, review the year, and order bees or supplies for spring. On warm days you will still see bees flying, a reminder that in California the calendar never fully stops.
How Do Inland and Coastal California Timings Differ?
This calendar is written for Santa Cruz County and the Central Coast, but California is a patchwork of microclimates, and the same month means different things in different places. Shifting the schedule to match your own conditions is the difference between working with your bees and working against them.
Warm inland valleys run the whole calendar earlier. In places like the Central Valley or inland Santa Clara County, manzanita and mustard can push colonies into buildup in December and January, swarm season can start in February, and the main flow may arrive and finish weeks ahead of the coast. Summer dearth also hits harder and hotter, so entrance reduction, water, and robbing control matter more, and heat limits which mite treatments you can safely use.
Cool, foggy coastal pockets run later and gentler. Persistent marine layer slows spring warm-up, so buildup and swarming may lag the inland schedule by two to four weeks. The upside is a longer, cooler bloom and a less severe summer dearth in fog-influenced gardens. The tradeoff is damp, which favors nosema and mold, so ventilation and dry hive conditions become the priority.
Higher elevations in the Santa Cruz Mountains behave more like a traditional cold climate, with a real winter cluster, a later start, and a shorter season. There, the mild-winter shortcuts apply less, and you should lean toward the higher end of winter store recommendations.
The practical takeaway is to treat this calendar as a starting template and adjust by watching your own bees and your own bloom. When your local manzanita and ceanothus flower, buildup is on. When the blackberries bloom, the flow is coming. Phenology (what is actually blooming) beats the calendar date every time.
Frequently Asked Questions
Why is the California beekeeping calendar different from national guides?
California's mild, Mediterranean climate means colonies begin building up in January instead of March or April, swarm earlier, and rarely face a hard winter. Most beekeeping calendars are written for cold climates where winter survival dominates. In California, according to the UC Master Beekeeper Program, the bigger challenges are the summer nectar dearth and mite management, so following a cold-climate schedule leaves you monitoring and treating weeks too late.
When should I check for swarm cells in California?
On the Central Coast, begin weekly or ten-day inspections for queen cells in March and continue through April, when swarm pressure peaks. In warm inland valleys, start in late February. Swarming happens earlier here than in most of the country because colonies build up during our mild winters. Adding space before the bees feel crowded and splitting colonies that show swarm cells are the two most effective prevention tools.
When is the honey flow in California?
The main nectar flow across most of California runs from late spring into early summer, roughly April through June, when blackberry, sage, buckwheat, and garden plants bloom heavily. Exact timing shifts by microclimate and elevation. Coastal areas may flow slightly later, and inland valleys earlier. After the main flow, most of California enters a summer dearth as the landscape dries out, which is when robbing pressure and mite levels rise.
When should I treat for varroa mites in California?
The most important treatment window is late summer, typically August, right after honey supers come off. According to the UC Statewide IPM Program, this timing protects the winter bees the colony is raising, and the treatment threshold drops in late summer and fall. Always monitor first with an alcohol wash, treat only if you are over threshold, and never apply honey-contaminating treatments while supers are on the hive.
Do California bees need to be fed in winter?
Usually not, if the colony is healthy and went into winter with adequate stores. Because California winters are mild and bees often forage on warm days and on early bloomers like manzanita, colonies burn less honey than in cold climates. General guidance is to leave roughly 30 to 50 pounds of honey. Heft your hives through winter and provide emergency feed only if a colony feels dangerously light.
What blooms in a California winter to feed bees?
Several California natives bloom in winter and early spring, giving colonies an early start. Manzanita can bloom as early as January, followed by early ceanothus (California lilac), wild mustard, and willows. These early nectar and pollen sources are why California colonies begin building up while cold-climate hives are still clustered. Planting winter and early-spring bloomers supports both your bees and native pollinators through the leanest months.
A calendar is only useful if it matches your actual climate, and California's does not match the guides most beekeepers learn from. Keep this month-by-month rhythm handy, adjust it a few weeks for your own microclimate, and you will stay ahead of your bees instead of chasing them. For a printable seasonal planner and our full library of local guides, visit your Garden Toolkit, and join our email list for timely Santa Cruz County gardening and beekeeping reminders.
