Planting for Bees and Microbes at the Workplace

Continuing to share the progress of my side project at work, I have received a fairly constant flow of compliments from my fellow associates at the cabinet factory. For those just tuning in, I had brought the idea of bringing in pollinator-friendly drought-tolerant plants to the landscaping, formerly a sorry sight with a lot of bare compacted clay. I was allowed to remain on the clock, and they even supplied me some money to purchase plants. Some of the plants came from me, I had an overabundance of some such as Stachys byzantina which is easily divided by division. Also planted here is Yucca filamentosa, various Thymus, Euphorbia × martini, and a few bearded irises. There are more Crocus to come, the ones blooming now are mostly C. sieberi and C. chrysanthus. Honeybees had been interested in these flowers yet I haven't seen any since last week.

Crocus chrysanthus growing out of a rock crevice

I have also been amending the "soil" (or more appropriately dead lifeless compacted clay). By adding sand and organic material, as well as inoculating the roots of the plants before I plant them, I am creating a more hospitable environment for plants to grow in. Mostly, I have been inspired by the book Teaming with Microbes: The Organic Gardener's Guide to the Soil Food Web (Revised Edition) by Jeff Lowenfels and Wayne Lewis (Timber Press, 2010). Get it. By adding beneficial microbes such as bacteria and fungi to the soil, I hope that a soil food web can develop which can benefit the plants in a variety of ways. Plants, in turn, benefit soil life with root exudates (exuded molecules of various substances such as sugars, polysaccharides, and most importantly, carbon) which are a food source for many beneficial microbes that live right around or in the roots (aka the rhizosphere).

Crocus growing out of a corner of a curbed parking island

With a healthy soil food web, good soil structure is formed, and nutrients are continuously made available to the plants without the need for fertilizer (synthetic fertilizers actually harm soil life). As the microbes (bacteria, fungi, protozoa, nematodes, microarthropods, etc.) eat and are eaten themselves (it's a vicious world down there), they are constantly releasing nitrogen and other trace elements that would otherwise be in forms that are useless to plants. A soil which is teaming with a diversity of microbial activity can out compete pathogens, too. Also important in this planting, beneficially parasitic mycorrhizal fungi can reach far beyond the roots extent to supply the plant with out of reach moisture and nutrients.

Rock garden, South side

 On the other side of the office, this is a hotter location which receives radiant heat from the metal walls and direct afternoon sun. Interestingly, the same amount of Crocus were planted here yet there are fewer blooming. Like the other planting, there are a variety of plants here that will be of use to bees, all inoculated with mycorrhizae, other fungi, and beneficial bacteria. In essence, the soil microbes will be benefiting pollinators when they allow the plants to take up more nutrients and moisture, enabling improved nectar production. They are all connected, through plants.

Rocks create microclimates

The soil here was amended by layering organic mulch with sand, sharp decomposed granite, and pea gravel. The rocks create microclimates, offering some shade and perhaps some residual moisture since the rocks block or delay evaporation. Some plants, like the Sedum reflexum barely seen shaded against the large rock in the foreground, do better with some afternoon shade in this climate (USDA zone 7b)

Happiness!