Diversify garden plantings Different types of pollinators have preferences for the plant type or flower structure that they visit to collect nectar or pollen resources. For example, hummingbirds have long beaks and tongues that can access nectar that other pollinators cannot. Additionally, other pollinators such as bats and moths visit flowers that are primarily open at night. Having a large diversity of plants ensures that pollen and nectar are accessible for a variety of pollinators. Some pollinators, like bees, require both nectar and pollen from flowers to meet their nutritional needs, whereas hummingbirds need a constant supply of nectar. A large variety of flower resource types allows for greater pollinator diversity.Use native plants Many pollinators have tightly interwoven relationships to native flowering plants. Pollinator emergence and life cycles are often synchronized with their preferred plants’ flowering patterns. It has been documented that native bees forage on native plants more frequently than on non-native plants . Native plants are also well adapted to the state or region’s localized climate and soil conditions.
Native California desert plants, such as desert globemallow , black plastic plant pots may be native to hot deserts; however, they thrive in cooler, coastal parts of the state as well, and the mallow attracts native bees wherever it is planted. Consider leaving flowering weeds Many plants that are considered weeds are actually attractive to pollinators. Leave some areas of the garden weedy for use by pollinators. This area can also serve as a bare-soil nesting area for native bees. Remove weeds immediately after flowering begins to decline to discourage them from setting seed or becoming invasive. Some weeds that are regularly used by pollinators include thistles , bristly ox tongue , and dandelions . Provide water Some pollinators, such as honey bees, need water for their survival. Maintain a shallow dish or bird bath with a landing surface to keep pollinators hydrated. Two methods to prevent honey bees from drowning are to place pebbles or stones in the dish or use a piece of floating cork board or wood. Some bee pollinators, including the blue orchard bee , require mud for nest construction . Provide shelter All pollinators need a protected place to either raise their young, lay eggs, or hide from predators. Types of cover include bird houses, bat houses, native bee boards or boxes, trees, shrubs, grasses or weeds .Avoid pesticides Pesticides not only kill the desired pest in your yard, but they can also harm valuable pollinators and beneficial insects that can provide pest control, given the chance.
Using pesticides in your garden may do more harm to your environment, including your pets and you, than what you might gain from using them. Avoid pesticides whenever possible, and use only cultural or biological controls to control the target pest. Also consider removing problematic plants and replacing them with another plant type. Refer to the University of California Integrated Pest Management website for information about controlling home garden pests safely by using the least toxic methods. Another resource is the brochure on pollinator-friendly pest solutions found on the Pollinator Partnership website .Recent news media has attracted public attention to honey bees since they have begun to decline under a series of pressures, including colony collapse disorder . Although native bees are not affected by CCD, they are susceptible to population decline from their own natural enemies and human disturbances. A growing public concern is currently about bee conservation. This new awareness, coupled with education surrounding native bees, has gardeners searching for ways to provide habitat. Honey bees are the most recognized and abundant bee in most gardens. Domesticated honey bees are generalized foragers, meaning that they visit a wide variety of host flowers. Native bees have more specific relationships to plant types and groups; they come in an array of colors, sizes, and shapes, and exhibit a wide range of fascinating foraging and nesting behaviors.
These predictable relationships between native bees and their flowers are the basis for planning a successful bee habitat garden. Select plants from the recommended plant list that attract both honey bees and a variety of native bees. A bee garden has four main components: 1) preferred plants, 2) single-flower types grouped into individual patches, 3) seasonal sequence of nectar and pollen , and 4) at least 20 plant types. A water source is necessary for honey bees but not for native bees. A highly variable habitat garden should start with at least 20 plant types to provide resources for a variety of bee species throughout the year. An ideal bee garden would have at least 20 patches of flowering plants with each plant type in its own patch. To select plants, consult table 1 as well as recommended plant lists from recognized online resources, such as the UC Berkeley Urban Bee Lab website . It is important to select a variety of plants with nectar or pollen, as they are both necessary to meet the nutritional needs of native bees. Native bees have taxonomic groups with distinct emergence times that can be matched with their preferred floral hosts. Native bees have four distinct foraging seasons, while honey bees continue to forage through all four seasons . For example, early spring bees emerge in February to visit plants such as Ceanothus species and Arctostaphylos species . Selecting plants to match multiple bees’ foraging seasons will encourage diverse groups of bees to visit your garden. Through careful placement of plants, one can increase flower foraging for bee visitors. Arranging plants in patches of one plant type, with patches measuring at least 4 by 4 feet, will catch bees’ attention as they search for flowers. Patches encourage bees to forage longer, and they make bees easier for gardeners to observe. Bees are always searching for new plants , which means that once the new habitat is completed they will be quick to appear.Soil-nesting bees Providing nesting resources for native bees transforms a habitat garden that allows bee populations to build up through time. Approximately 70 percent of native bees in California are solitary ground nesters, while 30 percent are cavity nesters. Ground-nesting bees look for patches of bare soil or soil with light leaf litter to construct nest tunnels to build their brood cells. Nesting is the least studied component of native bee ecology, and only general knowledge exists about the best soil type for native bees. Soil preferences vary from species to species, black plastic planting pots with preferences ranging from sandy soils to clay-based soils. The best approach to encourage bee nesting is to leave the entire yard or a sunny area mulch-free. Common gardening practices of heavy mulching create physical barriers that prevent native bees from nesting, so use mulch sparingly. Cavity-nesting bees Cavity-nesting bees include those that use existing holes or spaces in which to construct their nests. One can help these bees by providing artificial nest sites for them, which are easy to construct or purchase from commercial outlets. Most cavity-nesting bees prefer to use dead-end holes 4 to 6 inches deep and 3⁄16to 5⁄16inch in diameter. Hollow sticks, reeds, bamboo sections, and drilled holes in wood blocks meeting these measurements are suitable for use. Normally these are tied into bundles with wire and hung horizontally in a protected and warm, north-facing area. A tiny roof can be added for additional protection from rain. Note that exposure to direct sunlight for extended periods may overheat the nests and kill the brood. We also recommend cleaning or discarding nests after 2 years of use to prevent a buildup of parasites and diseases. On its website, the USDA Agricultural Research Service provides a wealthof information on techniques for constructing artificial nests and managing bees that use them .
One cavity-nesting bee, Osmia lignaria, commonly referred to as the blue orchard bee , has proven effective in pollinating crops such as apples, cherries, and almonds. This bee prefers 5⁄16-inchdiameter holes for its nest sites, but it also requires mud to construct the brood cells and close the entrance of completed nests. Growers and gardeners wishing to attract this bee can assist it by providing a nearby source of clay mud in a tub or trench . Besides the blue orchard bee, many other bees and beneficial predatory wasps may use the nests, providing a fascinating window into the little known world of garden ecology .A butterfly garden provides habitat for adult butterflies and their offspring to thrive . Host plant flowers are critically important to maintaining butterflies’ habitat. Providing preferred nectar-rich plants for adults is the starting point for providing habitat for these magnificent insects . It is important to plant various flowers that provide nectar in bloom from late summer into early fall when butterflies are most abundant. When adults visit a garden, they are not only looking for a sip of sweet nectar—they are also scoping out potential plant hosts upon which to lay their eggs. Butterflies do not feed and raise their offspring; once their eggs hatch, the larvae feed on the plant their mother has chosen for them until they are ready to pupate, transforming into a chrysalis. These eggs will be laid on specific host plants known instinctively by the adult to be a nutritious source of food for her caterpillar offspring. Caterpillars are messy eaters, leaving chewed-up leaves and droppings as evidence of their presence. While their feeding results in less than-picture-perfect plants, these host plants are a necessary food source for the growing caterpillar. If chewed leaves or flowers are undesirable, consider planting host plants in an out-of-the-way part of the garden .Plant attributes associated with hummingbirds include floral characteristics like a long trumpet shape, red color, large amounts of nectar, and little or no scent. Many tropical plants and at least 150 flowering plants in North America have evolved these characteristics to encourage hummingbird visitation . Hummingbirds use their uniquely shaped long bill and tongue to dip deep into flowers to access nectar that is inaccessible to most other pollinators. The flowers in turn have evolved to place pollen on the hummingbird’s head or body when it drinks nectar. Creating a garden with hummingbird plants, nesting habitat , and feeders will ensure visits from these fascinating birds. However, supplying them with a clean, nutritious food source requires weekly maintenance. Begin with a clean feeder and add a sugary solution that is one part sugar to four parts water. Using honey or a stronger sugar concentration could be harmful or even fatal. Adding red dye to the solution is discouraged; most hummingbird feeders have red parts that will catch the hummingbird’s eye. Feeders need to be taken down to be cleaned and refilled weekly. Wash the feeder with hot, soapy water, and rinse with hot, boiling water. Refill it with a fresh supply of solution, which can be made ahead and stored in the refrigerator. It is important to discard the old solution, as it can ferment into alcohol. If you live in a very hot area, the feeder should be cleaned and solution replaced every 2 to 3 days.The world’s population is predicted to reach nearly 11 billion by 2100; thus, sustainable agriculture and food safety are foremost issues . However, environmental pollution, increasing urbanization, and the gradual decrease in fertile soils have complicated these issues . It has become a critical priority to develop safe agricultural products to support environmental and human health. One innovative solution to the challenges presented by infertile soil and the need for water conservation may be soilless agriculture . Soilless agriculture is growing in popularity among commercial farmers because it eliminates soil-borne problems. The global market for hydroponic systems is estimated at $9.5 billion in 2020 and is predicted to reach $16.6 billion by 2025, growing at a five-year compound annual growth rate of 11.9% . The main strategy in soilless agriculture is to keep the system as clean as possible. However, a new trend is the inclusion of beneficial microorganisms to enhance the resistance to biotic and abiotic stress factors in the plants . Although beneficial microorganisms are found throughout the soil, they are most prevalent near plant roots in an area termed the rhizosphere . PGPRs are mostly obtained from the soil.