Growing food crops requires a multitude of things to be successful: water, nutrients, sunlight, and pollination are just a few examples. In the Pacific Northwest, gardeners can be challenged by some of those, especially the number of warm, sunny days we receive.

Climate change is slowly increasing the number and timing of warm days we receive. That is good for our food crops, right?

Well, maybe not.

Three of the 10 largest food crops in Washington — apples, cherries, and pears — require pollination from honeybees to be successful. The Washington State Department of Agriculture estimates that, annually, over $3 billion worth of crops can be directly attributed to honeybees. Clearly, honeybees are critical to not only the state’s economy but also to its food supply.

While a longer growing season with more warm days may be good for the crops it is not as good for the state’s honeybee population. Honeybees are incredibly hard workers and are dependent on weather conditions to leave the hive and forage.

When temperatures are below 55°F, bees will remain in the hive, resting and huddling together to keep the hive warm. But when temperatures hit 65°F bees will leave the hive and forage for food and water. Unfortunately, bees are programmed to fly and forage during these warmer times, regardless of how much food and honey is currently in the hive. In other words, worker bees (the bees who leave the nest to forage) can work too much.

Climate change in the Pacific Northwest is resulting in more warm days during both spring and fall. And as noted above, this is resulting in bees working longer and harder than they need to. Instead of preparing for the winter, bees are out foraging. As temperatures drop in the autumn and the bees return to the hive for the winter, they are smaller and have less energy reserves from the additional time they are out flying and foraging.

While they may be able to survive the cold winter, in the spring, these smaller adult worker bees start flying again and because of the smaller size and decreased energy reserves when they exit the colony, they are dying at an increased rate. If too many adult bees die before their replacements emerge ready to forage, the whole colony can collapse.

Losing these vital farming partners would not only be devastating to the state’s economy but also to the supply of key crops across the country. Researchers at Washington State University (WSU) and other organizations are researching ways to help reduce the risk of colony collapse. For example, these researchers are exploring moving human-managed hives into cold storage to simulate what was traditionally a shorter flying season for the bees.

Minimizing impact

While they continue to explore alternatives, how can we help minimize this impact?

First, gardeners can learn about the principles of Integrated Pest Management (IPM). Briefly, IPM is an eco-friendly approach to pest control that combines biological, cultural, physical, and chemical methods to minimize risks to humans and the environment. This approach greatly reduces, and often eliminates, the need for chemical applications.

Bees are opportunistic foragers, and they go where the food is. Even a small amount of chemical can be deadly to the bee. If chemicals are considered they should never be used when plants are flowering and bees are active: always read and follow directions on the pesticide label.

Second, plant a pollinator garden. Include some flowering native plants. Even if you do not have fruits or plants that require pollination, planting a pollinator garden will attract and feed bees and other pollinators. Having more local food sources throughout the year will reduce the amount of time and distance bees will be flying, thus helping preserve mass and energy stores.

Third, provide water. Bees drink too! Use a shallow bowl or place rocks in a deeper dish so they can rest while drinking. Keep the water no deeper than one-half inch, and ensure rocks are not fully submerged to prevent drowning.

Last, delay spring garden cleanup. Bees and other pollinators often over-winter in the leaves and other yard debris. By raking the yard early (before April or May), bees may become disturbed before they are ready to emerge and fly away. If the garden must be tidied, it is recommended that you maintain a debris pile to allow time for the bees to emerge. Once the pollinators leave, generally after a consistent week of 65°F or higher, it is safe to dispose of the debris.

While WSU and other organizations continue their work, please remember to “bee happy.” Every one of us can help this situation by being bee friendly and encouraging and welcoming these wonderful insects into our home yards and gardens.

For further information on IPM, bees, pollinator gardens, or other ways to help, investigate the WSU extension website at https://mastergardener.wsu.edu/resources/gardening-in-washington-state/.

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Dale Dallman is a Clallam County Master Gardener intern.