This is the second of two columns on how to make your garden bee friendly. Last week's column discussed the absolute necessity of eliminating the use of broad spectrum insecticides that are highly toxic to bees. Especially targeted are neonicitinoids or "neonics" (imidacloprid, clothianidin, etc.) that are applied both as sprays and systemics and that are identified as one major cause of colony collapse disorder in honeybees.
This column will describe what bees need to find in your garden in order to stay healthy and active there.
I've seen several types of bees (honeybees, carpenter bees, bumblebees) gather at the slightly leaky hose bib to get a drink while I'm watering the potted plants. Clear, clean water that moves or trickles and that is in the shade will attract bees.
UC Davis apiculturists have been working with orchard owners to design such a water source for the honeybees that are brought in to pollinate.
The system they've put together won't work in our gardens but a small shallow bowl with a solid edge that they can sit on while drinking will do just fine.
Most bees, about 70% of the species, are soil dwellers. If you can leave some bare dirt (no mulch) in your garden for bees to nest in, they will come.
There are many types of bee condos available now that attract and shelter bees as well. Most have an arrangement of hollow tubes that act as nests for the bees. If you've seen perfect half circles cut out of the edges of your plant leaves, it's the work of leaf cutter bees that line their tubular nests and swaddle their larvae with the leaf pieces.
Providing sources of clean pollen and nectar throughout the growing season is paramount in bringing bees into your garden. Different species of bees forage during different seasons.
Planting groupings of varieties of nectar and pollen-bearing garden flowers that bloom from early spring to late fall will guarantee a continuous food supply for bees.
The Bay Area Urban Bee Gardens website, http://nature.berkeley.edu/urbanbeegardens, provides a good list of bee types, their seasons and the flowers that they prefer. Some of the recommended trees and flowers though are not suitable for planting in our zones: zones 8 and 9 in the Central Valley, zone 7 in the foothills.
Many growers use neonic systemics to coat seeds and to treat greenhouse plants. Organic seeds and organic growers do not use pesticides to treat their seeds or plants. Buying organic seeds and plants will ensure that the pollen and nectar sources in your garden are safe for bees.