UC Berkeley Urban Bee Lab - Seasonal Bee Gardening
At numerous talks to
Provide Food
One of the best ways to initially attract wildlife to your garden is to provide food. In the case of bees it’s with flowers that provide nectar and pollen. Hummingbirds are attracted to gardens that have nectar rich flowers like CA fuschia, salvias, and columbines. Feeders are also a good way to supplement their nectar needs, especially in months when there might not be much flowering. Hummingbirds also feed on small insects and you can often observe them eating them from spider webs in shrubs or trees. Birds are also common garden visitors and providing them with food can be easily done by putting up a bird feeder and planting flowers that provide seeds for them, such as sunflowers. Sunflowers also feed bees by providing them with nectar and pollen, and when the seeds form many different birds can eat them.
When we talk with gardeners about attracting native bees to their garden we stress the fact that bees need floral resources (pollen and nectar) all year long. Adult bees feed on sugary nectar for energy. The pollen they collect is a protein and vitamin rich source which they will feed to their young. Nectar and pollen are combined to form a “bee loaf” that females provide for their larvae to feed on. Bees have seasonal emergence patterns, which means that different species emerge from their nests at different times of the year. Some species emerge in very early spring, February and March, whereas others come out later in spring as well as in summer and early fall. Bees have timed their emergence with the bloom of native flowers they prefer to forage on, but will also visit non-native ornamental flowers that may be in bloom at the same time. Some early flowering plants that provide food for bees includes: CA Lilac (Ceanothus sp.), Manzanita (Arctostaphylos sp.), Wisteria (Wisteria sp.), and Pride of Madeira (Echium candicans).
Provide Cover and Places to Raise Young
Another key aspect to habitat gardening is providing cover and places to raise young. Most native bees are solitary nest makers and build their nests in the ground or in pre-existing cavities. This can be provided through nesting blocks or by leaving bare patches of soil or sand in your garden. In the Oxford Tract bee garden we have done a combination of things. We have bee blocks hanging under the umbrellas as well as bundles of hollow dried out sunflower stems to attract cavity-nesting bees (sunflowers have multiple uses in the garden!). Be careful when choosing places to hang nests. They must be out of the direct sun and protected from rain so they don’t get moldy. We also have oak barrels filled with both sand and soil for ground nesting bees. Bees have also been seen nesting in soil banks where they can easily dig through the dirt. If you are a “mulcher” make sure to leave some bare dirt areas because bees will not dig through a thick layer of mulch.
Other garden visitors need places to raise young as well. Bird and bat houses are easy to build and can provide protected areas for nests and roosting. Bat houses should be mounted 12-15 ft. above the ground and protected from the wind and are most successfully colonized if you live close to water. Birdhouses can be mounted anywhere from 5-30 ft. above ground. Not all birds have the same nesting preferences so set up many houses in different parts of the garden to have the best success. Plants can also provide places to raise young for insects like butterflies. Butterflies need larval host plants for caterpillars to feed on, like milkweed (Asclepias spp.), if you want to attract Monarch butterflies to your garden. Research the wildlife you see in your garden in order to pick the right plants and provide the best nesting requirements. Cover can be provided in the form of thickets and brambles, as well as with log or rock piles.
Provide Water
Water is also a key resource for wildlife and there are many ways to provide this. Birdbaths are easy to make and can provide many species with a place to clean off. Not only will birds bathe in these baths, but they (and other animals) will also drink from them. Place them near windows so you can watch them as they fluff up and take a dip. Creating a pond can also be a great way to provide water to the wildlife in your garden. Be sure to monitor ponds as they provide habitat for mosquito populations. Puddles can also attract butterflies, honey bees, and bumble bees that will sip water and extract minerals and salts from the soil.
Garden design is also important when planning your habitat garden, especially with the goal of attracting native bees. We have found that large patches of one single plant type are the most attractive to bees as well as butterflies. If you have the space, a patch size of at least one meter by one meter should be designated for each plant species. The patches provide more resources (nectar and pollen rewards) and allow bees to forage in one spot for a long period of time. If plants are scattered it means bees have to spend a lot of energy flying from one plant to the next making them less efficient pollinators and harder to observe at work in the flowers.