Bee gardeners are good stewards of the environment, which includes making the most of our precious water supplies in the garden. But are you getting the most Bees Per Gallon? We've recently completed a five-year study to evaluate the bee-attractiveness of common northern California landscape plants. Funded by the USDA-NIFA-SCRI, this work was part of a US-wide project to investigate how the horticulture industry can support bees. At UC Davis, we evaluated low- and medium-water plants that do well in northern California.

While all the plants we tested were bee-attractive to varying degrees, here are the ten most-attractive plants with WUCOLS ratings of L or VL in the Central Valley region. These are the plants that will help your garden support the most bees with the least water -- the most Bees Per Gallon!

This list is not intended to be a comprehensive recommendation. There are other great low-water bee plants (here's a list on the Haven's website); the most detailed recommendation for California bee plants of all water needs is in California Bees and Blooms by Heyday Press.

 

Yarrow (Achillea millefolium 'Moonshine' and 'Island Pink')

Full sun

WUCOLS rating for the Central Valley = L

Blooms summer and fall

Grows approximately 2ft h x 2ft w

Sunset zones 1-24

 

 

 

Cape balsam (Bulbine frutescens)

Full sun

WUCOLS rating for the Central Valley = L

Blooms nearly year-round

Grows approximately 2ft h x 3ft w

Sunset zones 8, 9, 12-24

 

 

 

 

California lilac (Ceanothus maritimus 'Valley Violet'). All California lilacs are attractive to bees, but this variety grows well in the Sacramento region.

Full sun

WUCOLS rating for the Central Valley = L

Blooms late winter

Grows approximately 1ft h x 4ft w

Sunset zones 5-9,14-24

 

 

 

Santa Barbara daisy, Mexican fleabane (Erigeron karvinskianus)

Full sun

WUCOLS rating for the Central Valley = L

Blooms nearly year-round

Grows approximately 3ft h x 3ft w

Sunset zones 8, 9, 12-24

 

 

 

 

California buckwheat (Eriogonum fasciculatum)

Full sun

WUCOLS rating for the Central Valley = VL

Blooms summer and fall

Grows approximately 3ft h x 3ft w

Sunset zones 7, 9, 12-24

 

 

 

 

Gaura (Gaura lindheimerii)

Full sun

WUCOLS rating for the Central Valley = L

Blooms summer

Grows approximately 2ft h x 2ft w

Sunset zones 2B-24

 

 

 

 

Texas ranger, Texas sage (Leucophyllum frutescens)

Full sun

WUCOLS rating for the Central Valley = L

Blooms late summer

Grows approximately 4ft h x 4ft w to 8ft h x 8ft w depending on variety

Sunset zones 7-24

 

 

 

 

Catmint (Nepeta x faasenii 'Walker's Low'). We tested this cultivar, but others are also bee-attractive.

Full sun

WUCOLS rating for the Central Valley = L

Blooms summer and fall

Grows approximately 2ft h x 2ft w

Sunset zones 1-24

 

 

 

 

Russian sage (Salvia yangii (Perovskia atriplicifolia))

Full sun

WUCOLS rating for the Central Valley = L

Blooms summer and fall

Grows approximately 2ft h x 2ft w to 6ft h x 6ft w depending on variety

Sunset zones 2-24

 

 

 

 

Wall germander (Teucrium x lucidrys (Teucrium chamaedrys))

Full sun

WUCOLS rating for the Central Valley = L

Blooms summer

Grows approximately 1ft h x 2ft w

Sunset zones 2-24

Conserving water and helping bees are goals shared by many gardeners. Given California's current extreme to exceptional drought status, it's time to re-visit the best low water plants for bees. Haven scientists are nearing the end of a long-term project examining bee preference for commonly used landscape plants. We've focused on low-water plants for northern California, while our San Diego-based colleagues have focused on southern California plants.

One of the consistently most-preferred plants has been Russian sage, Salvia yangii, formerly Perovskia atriplicifolia (read about its reclassification here). It's been either the first, second, or third most attractive plants to honey bees, and second, third, and sixth most attractive plant to native bees over the course of our observations.

Native to central Asia, this plant copes well with hot, dry conditions as well as extreme cold. It blooms from late spring to frost, providing a season-long bee resource. Like most members of the Lamiaceae, it serves only as a nectar source. Pair it with a complimentary colored pollen-providing plant in pink or red, like the coneflowers shown here, for both garden interest and bee nutrition.

 

Russian sage (Salvia yangii) and prairie coneflower (Ratibida columnifera)

It's that time of year: hurricane-force winds one day and beautiful spring weather the next. Here's what's happening in the Haven in March:

Garden maintenance

We've finished our winter pruning and are eagerly awaiting the flowers that will follow. Our winter-blooming plants are going strong, providing vital food for the honey bees at the Laidlaw Honey Bee Research Facility next to the Haven. Some top winter-blooming plants for bees include rosemary (Salvia rosmarinus -- yes, rosemary is now a salvia!), germander (Teucrium fruticans),

many Ceanothus cultivars,

Chaparral currant, Ribes malvaceum 'Dancing Tassels'

chaparral currant (Ribes malvaceum) and

Golden currant, Ribes aureum

golden currant (Ribes aureum). The last three are California natives. Native wildflowers like California poppy (Eschscholzia californica) are also valuable in the bee garden

California native annual wildflowers, such as golden lupine (Lupinus microcarpus densiflorus) and California poppy (Eschscholzia californica) are great March blooming plants for the bee garden. The purple flower is the non-native perennial, tall verbena (Verbena bonariensis).

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Garden irrigation

Our irrigation system is always given a going-over in the winter to ensure there are no leaks and that the precious water is being used as efficiently as our system will permit. We'll be working on this throughout March.

Garden plantings

This is the start of the time when the Haven changes almost weekly. If you're planning a visit, things really get going in late March, and the garden remains at its best through the end of May. Thanks to a generous donor, we had the funds to replant one of our display beds this winter. We'll be using additional support from our Crowdfund campaign to refresh our demonstration orchard.

If you'd like to plan your own bee garden, you'll find a searchable plant list on our website. The list includes bloom time, bee resources provided, Sunset growing zones, and water and light requirements. In addition to our full plant list, you'll find several targeted (e.g. low-water, shade, etc.) bee plant lists here.

 Garden education

Yolo County has moved into a lower COVID tier, and we hope to resume guided tours by the last week of March. Pending approval by the University and COVID restrictions on group size, we look forward to welcoming tours back to the Haven. The garden remains open for individual visitors.

In the meantime, we've loaded more videos to our YouTube channel; look for more throughout March.

Fundraising February

Thanks to everyone who donated, shared, or otherwise supported our February fundraising effort through Crowdfund UC Davis. We've nearly reached our goal of $2500. Contributions may be made here through February 28.  Thank you!

One of the top-performing plants in the Haven's bee attractiveness studies is Russian sage. Garden books describe this plant along the lines of "...even though it's called Russian sage, it's not a sage. That name is for plants in the genus Salvia...." To quote from the Sunset Western Garden Book, "This popular plant is neither a sage nor from Russia."

Well, the plant taxonomists have been at it again. So Russian sage, previously known as Perovskia atriplicifolia, has been reclassified and is now Salvia yangii. Just when we learned to pronounce per-ROVE-ski-uh! And to shake things up even more, rosemary is also now a salvia. It's understood to be a close relative of Russian sage and has been reclassified as Salvia rosmarinus. The correct way to write these is new name (old name). So Russian sage is Salvia yangii (Perovskia atriplicifolia) and rosemary is Salvia rosmarinus (Rosmarinus officinalis). 

Our understanding of Russian sage's native habitat remains unchanged. It's still not from Russia, but is native to grassland areas in western China, Pakistan, and Afghanistan. These hot, dry, sunny areas have summer weather similar to California's Central Valley so it does well in our gardens.

 

 

 

A close view of a bee on its flower shows the characters that we often associate with the genus Salvia. 

 

 

 

 

 

 

 

 

Here are links to some of the scientific papers describing these changes for those who wish to learn more:

Salvia yangii. National Center for Biotechnology Information. Link here. 

Taxon. 2017. Salvia united: The greatest good for the greatest number. Read here.

American Journal of Botany. 2012. Phylogenetics, biogeography, and staminal evolution in the tribe Mentheae (Lamiaceae). Read here. 

 

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