Garden Pollinators: Golden Northern Bumble Bee (Bombus fervidus)

 

Golden Northern Bumble Bee (Bombus fervidus): nectaring on garden onion

The third week in June is National Pollinator Week (https://www.pollinator.org/pollinator-week).   The word ‘pollinator’ conjures up images of Honey Bees for many people.  But the world of pollinators is far more complex.  Our Garden Pollinators series features some of the many interesting pollinators seen in Western Colorado gardens.  For more on pollinators in general – and tips for attracting pollinators to your garden – see: https://mothernaturesmontrosegarden.blogspot.com/2020/06/life-friendly-gardening-planning-for.html

Golden Northern Bumble Bee (Bombus fervidus): love native Penstemons

One of the busiest pollinators currently in Mother Nature’s Montrose Garden is the Golden Northern Bumble Bee.  This large, bright yellow bee is hard to miss.  You may have seen it in your own garden – or out in the wild.  Its range covers much of North America, with the exclusion of much of the southern United States, Alaska, and the northern parts of Canada. It can be seen in the wild, particularly in grasslands, as well as in cities and farmland.

The Golden Northern Bumble Bee was first identified by the Danish zoologist Johan Christian Fabricius in 1798. [1]  Bombus fervidus is quite similar to Bombus californicus, which has an overlapping range in the western U.S.    Like all Bumble Bees, the species includes males (drones) and two types of females: queens and worker females.

Golden Northern Bumble Bee (Bombus fervidus): characteristics

The Golden Northern Bumble Bee is a large bee, about ½ inch long for drones and workers and slightly more (over 3/4 inch) for the larger queens.  One’s first impression is of a large, very hairy, yellow Bumble Bee.  As seen above, the first four sections of the abdomen are yellow while the terminal segments are black.  The thorax is also mostly yellow, while the face and legs are black (below).  A black band is present between the base of wings.  The underside of the body is also mostly black in females, but may contain more yellow in males.  For more pictures of this species see reference 2.

Golden Northern Bumble Bee (Bombus fervidus): identification

A new Queen mates once with a male drone in fall; then she overwinters by hibernating in the ground. Queens emerge as the weather warms in spring and forage for pollen and nectar (they need energy) and a place to start their nest.  Nests may be either above- or below-ground (more common). Leaving areas of your yard undisturbed is a great way to encourage nesting in your garden.  Nests are made of grass and dung. The nest site is usually within about 150 ft. of flower resources.  

After creating her nest, a Queen collects pollen, which she uses to create food for her initial brood. The honey she makes is stored in special wax compartments – the ‘honey pots’ – in the nest. The nest is composed of individual cells and the Queen lays an egg in each cell.  This initial brood has up to 10 individuals.  When the eggs hatch, the larvae feed on honey until they metamorphose into adults.  Metamorphosis takes about 15 to 25 days.  The emerging adults are the smaller, female worker bees (below).

Golden Northern Bumble Bee (Bombus fervidus): female worker

Golden Northern Bumble Bee (Bombus fervidus):Queen

The first generation of workers provide all the food needed for the next generation of offspring, as well as for the Queen. From this point on, the Queen just focuses on laying eggs. The workers must work very hard; in fact, some work so tirelessly that their lifespan is shortened to a month or less. [3] Some workers expand the nest and keep it tidy. But the workers primarily gather pollen to feed the developing brood. They also chew pollen and mix it with their saliva to make honey. [1] Each generation will be slightly larger than the preceding generation, due to increasing food resources.

Golden Northern Bumble Bee (Bombus fervidus): Queen

The Queen is the only female that can produce female offspring (which only develop from fertilized eggs).  Later in the season, the Queen also lays unfertilized eggs; these develop into males (drones). Also late in the season, she lays eggs destined to become new Queens. These become larger than other females in the nest. Workers can also can lay unfertilized eggs, but these often don’t develop.  For more on the Bumble Bee life cycle see reference 4.

Golden Northern Bumble Bee (Bombus fervidus): great pollinator

Because they are such hard workers, Golden Northern Bumble Bees are excellent pollinators.  Click on the videos below to see how rapidly they work:

Vimeo

Vimeo

Bombus fervidus can be seen foraging whenever the day is warm. They are busy from early morning until evening in our garden.  And they visit a great many flower species. They have long tongues, allowing them to access nectar in tubular-shaped flowers. And they don’t hesitate to climb right into a Penstemon flower. But they nectar at a wide range of types of flowers (below.  They tend to favor plants with many small flowers in our garden: the milkweeds, lilacs, spiraeas, onions, mints, etc.  But they really love the penstemons!  

Golden Northern Bumble Bee (Bombus fervidus): on Apache Plume

Golden Northern Bumble Bee (Bombus fervidus): on Narrowleaf Coneflower

Golden Northern Bumble Bee (Bombus fervidus): on Garden Lilac

Golden Northern Bumble Bee (Bombus fervidus): on Nettle-leaf Agastache

The Golden Northern Bumble Bee is a wonderful pollinator to have in your garden. It is easy to attract, as long as you have plenty of floral resources from early spring through fall.  The Bumble Bees are fascinating to observe – children of all ages enjoy watching them (including us elders). 

Like many Bumble Bees, Golden Northern numbers appear to be decreasing. Part of this decline is almost certainly due to loss of habitat.  Providing food and a place for Bumble Bees to raise their young is a simple way to be a good citizen. It will also guarantee more garden seeds for next year!  

So, plant some native plants and the Bumbles will come. Then upload your photos to Bumble Bee Watch: Bumble Bee Watch.

Golden Northern Bumble Bee (Bombus fervidus): on Palmer's Penstamon

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1. Bombus fervidus - Wikipedia
2. Bombus fervidus - -- Discover Life
3. ADW: Bombus fervidus: INFORMATION (animaldiversity.org)
4. Life Cycle and Biology – Bumble Bees of Wisconsin – UW–Madison

 

 

 

We welcome your comments (below).  You can also send your questions to: monaturesmontrosegarden@gmail.com

Plant of the Month (June) : Sulphur Buckwheat – Eriogonum umbellatum

 

Sulphur Buckwheat (Eriogonum umbellatum): Mother Nature's Montrose Garden

There’s nothing like a mass of yellow blossoms to brighten a garden. Our native Sulphur Buckwheat provides a welcome yellow-and-rust accent from May through the summer. That’s why it’s one of the perennial favorites in Mother Nature’s Montrose Garden. The scientific name is pronounced air-ee-OG-oh-num   um-bell-LAY-tum.

The Sulphur Buckwheat is one of about forty Colorado native buckwheats, with three-quarters of them native to the drier Western Slope. Only one-quarter of the Colorado buckwheats are annuals; the majority are either perennials, sub-shrubs or shrubs.  Many make attractive additions to the home garden – if you can find them!

Eriogonum umbellatum is native to Western North America from British Columbia to California on the west coast, and east to Wyoming, Western Colorado and New Mexico. It typically grows in dry, open, often rocky places from sea level to alpine (to 13,000 ft). On the Western Slope, the several variants can be seen in sagebrush flats, on dry slopes, in mountain meadows and in pinyon-juniper, conifer and sub-alpine forests from about 5000 to 13,000 ft [1500-4000 m.] elevation. [1]

Sulphur Buckwheat (Eriogonum umbellatum): California variety

The wide elevation range makes this plant suitable for many gardens in the Western U.S.  Local native plant nurseries often sell local varieties, which often are best suited for regional conditions.   Many native buckwheats, including Eriogonum umbellatum, are also drought tolerant - a welcome bonus, as we transition to more water-wise gardens.

Sulphur Buckwheat (Eriogonum umbellatum): growth habit

Sulphur Buckwheat is quite variable across its range and varieties. It grows as a perennial or sub-shrub, with some variants less than 6 inches tall while others reach up to 3 ft.  Plants have a mounded or mat-like growth habit (above). We grow the ‘Kannah Creek’ type (Eriogonum umbellatum v. aureum ‘Kannah Creek’), a natural cultivar from the near us on the Western Slope.  It reaches 12-15" tall by 15-24" wide, with plants increasing in width with age.  This cultivar is available from several on-line vendors, including High Country Gardens and Annie’s Annuals.

Sulphur Buckwheat (Eriogonum umbellatum): foliage in basal rosette

Sulphur Buckwheat (Eriogonum umbellatum): leaf

The leaves of Sulphur Buckwheat grow in a loose basal rosette.  The leaves are simple, oblong-ovate or oblanceolate to elliptic to oval and may be hairy. The leaf margins are entire and may be wavy in some variants. Leaf color is medium green to gray-green (especially when dry). In colder climates, the leaves turn a rich red-brown with the frosts (below). Plants remain dormant during cold winters.  The species itself is quite cold tolerant and Colorado varieties can be grown in USDA Zones 4-8.

Sulphur Buckwheat (Eriogonum umbellatum): winter color

Growth rate for Eriogonum umbellatum is slow to moderate, with plants expanding to their mature size over several years (below). Plants have a long taproot, which makes them both drought tolerant and difficult to move when mature.  Plants can live to 20 years (perhaps slightly more) in the garden setting.

Sulphur Buckwheat (Eriogonum umbellatum): young plant

Sulphur Buckwheat (Eriogonum umbellatum): maturing plant

The flowers of Sulphur Buckwheat are spectacular.  The tiny flowers grow in umbels or compound umbels, on flowering stalks above the leaves (below). The flowers are small, sulphur-yellow when fresh, fading to rust orange after pollination (below). The flowers are perfect (both male and female parts in each flower) and the anthers (male, pollen-producing part) extend beyond the petals (this is common in the buckwheats).

Sulphur Buckwheat (Eriogonum umbellatum): flower color

Sulphur Buckwheat (Eriogonum umbellatum): close-up of flowers

The flowers are insect-pollinated, mostly by smaller native bees and flower flies in our garden.  But many other insects may visit this great habitat plant (below). The species is host (caterpillar) plant for the Acmon Blue (Icaricia acmon), Melissa Blue (Plebejus melissa), Blue Copper (Lycaena heteronea), Mormon Metalmark (Apodemia mormo), Square-spotted Blue (Euphilotes battoides), Dotted Blue (Euphilotes enoptes), and Lupine Blue (Icaricia lupini) butterflies. [2]   Birds eat the seeds, so resist the temptation to deadhead the flowering stalks.  They provide an attractive dark brown element to the summer/fall garden as well as providing bird habitat.

Sulphur Buckwheat (Eriogonum umbellatum): small native bee

Sulphur Buckwheat (Eriogonum umbellatum): insect habitat

Sulphur Buckwheat is easy to grow if you choose a variety native to your area and choose a suitable place in your garden. The best strategy is to try to mimic the  growing conditions for your local variety as much as possible. For example, ‘Kannath Creek’ grows in hot, sunny and rocky conditions. We’ve tried to provide those in Mother Nature’s Montrose Garden by planting our plants in the hot, rocky areas around our pond. 

Sulphur Buckwheat (Eriogonum umbellatum): warm, sunny placement

Full sun to part-shade and well-drained soils are a must. Buckwheat plants like a lean soil, so no fertilizer needed (except if grown in a container; even then, a light yearly dose is all). Sulphur Buckwheat tolerates alkali soils (to pH 9.0) and saline soils, both of which are common in some parts of the West.

Don’t over-water this water-efficient plant.  Let the soil dry out between waterings. And don’t plant in an area that gets boggy in the spring.  If your conditions are not suitable, you can even grow Sulphur Buckwheat in a container. Just give it plenty of growing room for its taproot.

Sulphur Buckwheat (Eriogonum umbellatum):
does well in deep containers

Given the right conditions, Eriogonum umbellatum is easy to grow. No pruning or other fussing required - just let the plant do its thing.  And that’s just one reason to include this plant in your garden.

Sulphur Buckwheat (Eriogonum umbellatum):
in Western Colorado garden

Then there’s the distinctive flower hue that adds a pop of color to any spring-summer garden. If you like wildlife, this is a great habitat plant for many insects, including the native spring pollinators.  The neat growth habit makes it a nice accent plant.  We particularly like the low-growing varieties for bordering paths in a water-wise garden. Some gardeners use the shorter varieties as a water-wise ground cover.  It’s a perfect accent in a rock garden.  And an excellent choice for those dry, hard-to-water areas of the garden.

Sulphur Buckwheat (Eriogonum umbellatum): looks nice
 with other native flowers and grasses

So, look around your garden and see if you have the right spot for some Sulphur Buckwheat.  It adds a sense of place to any Western garden. You won’t regret selecting this well-behaved and lovely plant.

 

Sagebrush Checkerspot on Sulphur Buckwheat (Eriogonum umbellatum):

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1. Ackerfield, Jennifer: Flora of Colorado.  Brit Press, 2015
2. Sulphur Buckwheat, Eriogonum umbellatum (calscape.org)

 

 

For a gardening information sheet see: Gardening Sheet - Eriogonum umbellatum.pdf (slideshare.net)

For more pictures of this plant see:

For plant information sheets on other Western native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html

 

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We welcome your comments (below).  You can also send your questions to: monaturesmontrosegarden@gmail.com