Habitat Gardens for Pollinators

Habitat Gardens for Pollinators
by Kathleen McCollum
July 2019

The majority of all ecosystems on earth depend on the services of pollinators for their existence (Ponder et al 2013). Pollinators are in decline and supporting the pollinators starts with awareness. The following text is intended to raise awareness and inspiration for the things we can do to support pollinators. So, let’s talk pollinators. We are going to describe who they are, why they’re important, what factors threaten them, and the relationship native pollinator have to native plants. Then, we will discuss California native pollinator plants for the Santa Ynez Valley and will describe their growing pattern, flowering time and growth requirements.

The Importance of Pollinators
Pollinators are fundamental to the health of the earth. Bees, butterflies, hummingbirds, moths, flies, beetles, bats and mammals transfer pollen from flower to flower which enables plants to produce seeds and fruits (Ponder et al 2013). Pollinators are responsible for the reproduction of 80% of the world’s flowering plants and more than one third of the world’s agricultural crops (ucdavis.edu 2019). Pollinators play an essential role in agricultural production, habitat and food for wildlife and the preservation of biological diversity on earth (Adamson et al 2017). Pollinators have experienced marked decline and are threatened by various factors such as habitat loss and pesticides. It is vitally important that habitat for pollinators are preserved and restored.

About the pollinators

Bees
Bees are a major group of pollinators for both crop and non-crop plants (Kremen et al 2002). There are 4,000 native bee species in the United States and 1,500 of them are native to California. Three quarters of the native bee population are solitary and do not form colonies or hives. These solitary bees typically nest underground or at the grounds surface using twigs, dead wood, and bare soil (Kremen et al 2002; Marks et al 2005; xerces.org 2016). The non-native European honey bee has received widespread attention regarding its importance to agricultural pollination and the colony collapse disorder (Marks et al 2005). Much less publicized is the native bee populations however they too are experiencing significant population decline (Kremen et al 2002). The role of native bees in the pollination for agricultural crops is largely undocumented, however, research shows that native bees have evolved to pollinate certain plants. When these plants are pollinated by native pollinators, they produce larger and more abundant fruits and seeds (xerces.org 2016; Kremen et al 2002).

Butterflies.  
There are over 700 species of butterflies in the United States and 200 are native to California (Adamson et al 2017). Butterflies have four life stages (egg, caterpillar, pupa, adult) Each life stage has different habitat requirements for example the caterpillars are very specific for their food source whereas adult butterflies require a diversity of plants (Ponder et al 2013). Butterflies lay their eggs on leaves and branches of shrubs and trees, grasses and wildflowers. And therefore, host plants are essential for supporting butterfly populations (Hoffman et al 2009) Some species of butterflies die before winter begins, some overwinter in coastal woodlands, while others hibernate underground in leaf litter and garden debri (Marks et al 2005).  

Hummingbirds
Hummingbirds are the most effective pollinating birds in North America. They have long beaks and tongues which allows them to reach into deep flowers and harvest nectar (Ponder et al 2013). Hummingbirds need trees, shrubs and vines for shelter, shade and nesting. Their nests are made out of plant fibers and are typically 5 feet from the ground in dense shrubs (Marks et al 2005; nwf.org).

Moths
Moths typically pollinate flowers in early morning, late afternoon or evening time.  Moths are harrier and typically less colorful than butterflies (Ponder et al 2013; Marks et al 2005).

Bats:
Bats are important pollinators for night-blooming flowers (Marks et al 2005). Nocturnal pollinators that play an important role in night flowering plants, especially in the desert regions (Ponder et al 2013). 40% of American bats are either endangered or suffering significant decline (Marks et al 2005).

Flies and beetles
There are hundreds of thousands of species of flies and beetles and they are important pollinators. 

Research shows there are some species of flies that are generalist pollinators and visit a wide variety of plants in search of nectar (Ponder et al 2013). In addition to their pollinating services, many flies and beetles are beneficial insects, and feed on aphids and therefore are also important for sustainable pest management approaches (Hoffman et al 2009). 

Native plants and Native Pollinators
Native plants have evolved together with native pollinators over thousands of years, have synchronized relationships and rely on each other for survival (Ponder et al 2013; ucdavis.edu 2019; nwf.org). It is often seen that flowering time of plants coincides with a particular pollinators active foraging time. For example, the southern hummingbird migration is synchronized with the flowering time of chaparral currant and California fuchsia(cnps.org; Bornstein et al 2005) These are not mere coincidences, this is proof of coevolution of plants and wildlife (nwf.org). Native plants are invaluable to native pollinators and vice versa. Native plants provide warmth, shelter, habitat and are a refuge for innumerous wildlife species (Bauer 2017). Native plants provide pollen (protein rich) and nectar (sugar rich) sources of food for pollinators. In exchange for this energy source the pollinators assist with the reproduction of plants.  

Threats to the Pollinators
The most significant threat to pollinators is the loss of habitat. The loss of habitat is caused by a variety of factors such as population growth, intensive agriculture, pesticides, invasive plants and climate change. Population growth increases the development of roads, resource extraction, suburban development and nature recreation (greatpollinatorproject.org, 2014). This leads to the shrinking, fragmentation and degradation of native habitats. Consequently, the quantity and quality of food sources for pollinators is decreased which increases the flight time between food sources. These factors weaken pollinators and make them susceptible to disease (Arathi et al 2018; ucdavis.edu 2019; Ponder 2013).

Agricultural intensification is a major threat to pollinators by reducing native habitats and the increased use of pesticides. Pesticides kill pollinators and sub-lethal doses can impact the ability to navigate and forage for food (Hoffman et al 2009). Furthermore, herbicides effectively remove much of the biodiversity that pollinators rely on for food and habitat (greatpollinatorproject.org 2014). Invasive plants are also a threat to pollinators by outcompeting native plants and non-native plants often don’t have as much pollen (Marks et al 2005).

Climate change is linked to decline in pollination services by disturbing the symbiotic plant-pollinator relationship. Plants may flower at different times for shorter durations, while pollinators may migrate at different times. Climatic fluctuations can shorten the reproductive season of pollinators, reduce flowering time and impact overwintering pollinators with unreliable weather conditions (Marks et al 2005; greatpollinatorproject.org 2014;Hoffman et al 2009).

Understanding the threats to pollinators is essential when taking action to support them. They need native habitat to survive and many human induced factors are degrading these habitats. We can assist the pollinators by integrating native plants that attract pollinators into the landscape and into our gardens, decrease pesticide use, promote sustainable use of the land and natural resources.  

Advice for Starting a Habitat Garden

We have researched the essential criteria for starting a habitat garden. To attract pollinators to your garden is it important to have adequate sources of food, shelter, water and nesting sites (Marks et al 2005). Integrating native plants into your landscape is a key strategy for supporting pollinators (Adamson et al 2017).

Select Native Plants
Choosing native plants ensures that the plants are adapted to the local soil and climate. Native plants provide the most substantial source of food for native pollinators (xerces.org 2016).

Plant a diversity of plant types
A diversity of plants can support various pollinators and their required food sources, overwintering and nesting sites (cnps.org; Ponder et al 2013). A habitat garden should include shrubs, trees, perennials and wildflowers. However, focus more on the longer living plant types(shrubs, perennials, trees)  as they provide a more stable source of nectar as opposed to annuals or wildflowers (Adamson et al 2017; Marks et al 2005).

Select plants for overlapping bloom periods
Ideally there is three species of plants in bloom during each season from spring through fall (xerces.org 2016). Different pollinators have various active times, so it is important that there is a food source for the pollinators throughout the seasons (Adamson et al, 2017; Kumar 2010). 

Plant a diversity of flower color and shapes
Choose a variety of different colors and shapes because different pollinators prefer different flowers (Ponder et al 2013). Bees are most attracted to white, blue, purple and yellow flowers. Butterflies prefer bright and fragrant flowers with surfaces that are flat and broad so that they can land on them. Hummingbirds are adapted to drink nectar from tubular, trumpet and bell-shaped flowers and love red, orange and yellow colored blossoms (Marks et al 2005).

Plant in patches
Plant 10-20 species for a diversity of nectar and pollen rich plants. Plant multiples of same species in patches because pollinators have an easier time recognizing the plants when the same species are in patches (Adamson et al 2017). 

Avoid pesticides
Avoid the use of pesticides or plants which have been pre-treated because these chemical substances are toxic to pollinators (Adamson et al 2017; Kumar, A, 2010). By planting a diversity of plants, you actually attract beneficial insects which aid in keeping pest populations in balance and can avoid spraying with chemicals. If you have to use something to control a pest start with use natural pest deterrents such as soap, garlic and chili pepper.  Spray only at night when flowers are not blooming, and bees are not foraging (ucdavis.edu 2019). 

Let the garden be
A habitat garden is a place that pollinators can raise their young, nest, overwinter and feed. Therefore, it is important to avoid manicuring the plants and instead allow dead plant material like branches, twigs, grass to collect on the ground for nesting sites, places to lay eggs, raising young and hide from predators (Ponder et al 2013). As many native bees nest underground it is important to not disturb the soil with tilling or shovels and wait until spring to tidy up the garden (Kumar 2010). 

Provide larval host plants 
Provide larval host plants for butterflies and other pollinators. Butterflies need host plants to lay their eggs on. Plant natives that are host plants to butterflies in the region (xerces.org 2016). Milkweeds are host plants to the monarch butterfly caterpillar. Many other native plants are host plants for butterfly or moth larva such as California rose, California aster, coyote mint, California Fuchsia, California Buckwheat, ceanothus and much more (xerces.org; Smith, N 2006).

Provide habitat structures
Understanding lifecycle and overwintering patterns helps to create a pollinator habitat that is supportive of the whole lifecycle of pollinators. Bee boxes, bat houses, and bird houses or even bundles of hollow stems can all serve as useful overwintering sites for pollinators (ucdavis.edu 2019; Xerces.org 2016).

Provide water
Pollinators need clean water for their survival and a shallow bird bath or dish helps them to receive adequate amounts of water. If you place pebbles in the water this can help them from drowning or use floating cork or wood (Ponder et al 2013). 

Top California native plants for the Santa Ynez Valley
Now that we have described the essential principles in cultivating a habitat garden we can talk about some of the best California native plants for the Santa Ynez Valley. We have researched some of the plants that will do great in this region and have described their plant description, growing requirements, and the pollinators that they attract.

Yarrow 
Achillea millefolium

California Lilac
Ceanothus thyrsiflorus ‘Skylark’

California Buckwheat
Eriogonum fasciculatum

Coyote Mint
Monardella villosa

Chaparral Currant
Ribes malvaceum

California Wild Rose
Rosa californica

Cleveland Sage
Salvia clevelandii

California Goldenrod
Soldagio californica 

California Aster
Symphotrichum chilense

California Fuchsia
Epilobium canum

Howard McMinn Manzanita
Arctostaphylos ‘Howard McMinn’

Winter-Spring Flowers

Chaparral Currant
Ribes malvaceum

Chaparral currant is a deciduous shrub that will grow to be 4-10 feet tall and has gorgeous clusters of dusty pink to rose red blossoms from December through March (Bornstein 2005). In late summer and fall it often will go dormant and will revive with cooler temperatures and the onset of rain (Smith 2006). It is a tough and reliable shrub that is easy to grow and can tolerate a variety of soil conditions. Provide the plant with dappled shade and light summer irrigation (Bornstein et al 2005). Chaparral currant is one of the earlier flowering natives which makes them a very valuable source of nectar for hummingbirds, and the berries in the summer are important food source for birds (Bornstein et al 2005; cnps.org).

Spring-Summer Flowers

Cleveland Sage
Salvia clevelandii

This semi-evergreen shrub grows to be about 3-5 feet tall. In late spring flower stalks begin to bloom with immensely fragrant violet and blue flowers. Establish this sage on a sunny site with well-drained soil. Provide the plant with water as it becomes established, but a mature sage will need very little additional watering (Bornstein et al, 2005; Smith, 2006). Pruning will maintain plant vigor, however avoid cutting into mature hardwood, as these often do not re-generate new growth (Bornstein et al 2005). Make sure you provide this plant with enough space to spread out. Sages are a very important component of a habitat garden and are frequented by hummingbirds, butterflies, moths, bees and bumblebees and the seeds are valuable to birds (Ritter 2018).

California Wild Rose
Rosa californica

California wild rose is a deciduous shrub which grows to be about 3-7 feet tall. Their fragrant pink-white-magenta blossoms have five petals and appear from spring to early summer. Rosa californica is easy to grow and is adaptable to a variety of soil conditions and thrives in many landscapes. Establish these plants in partial shade with occasional summer watering in a semi-moist position in the garden (Bornstein et al 2005). This is an important species in a habitat garden. The blooms are pollinated by native bees and bumblebees and once pollinated, these flowers will form into a rose hip which provides food for birds and mammals and a lovely fall and winter color to the landscape. There dense thickets provide cover for birds, insects, and animals and also can be used as a living barrier or hedge (Ritter 2018; Calscape.org).

California Lilac
Ceonothus thyrsiflorus ‘Skylark’

Skylark is valuable for its compact size reaching about 4-6 feet tall. In late spring through early summer the shrub is covered with abundant brilliant cerulean blue blossoms. Skylark is actually one of the later blooming ceanothus varieties. This plant prefers full sun to part shade and well-drained soil and needs very little to no fertilization. Plant in fall when there is rainy season for it to become established. Once established you can limit to infrequent supplemental watering (Bornstein et al 2005). This plant is an essential plant for a habitat garden, as the bees, butterflies and hummingbirds love it. Some species of moths and butterflies use ceanothus as larval food, and it provides food and cover for many wildlife species (Smith, 2006; Ritter, 2018).

Yarrow
Achilliea millefolium

This semi-evergreen herbaceous perennial grows to be about 3 feet tall and blooms in spring through summer. Their flowers are cream to pink and clustered in an umbrella shape. Their leaves are aromatic, soft, narrow and feather like. They prefer a sunny or partly shaded place, occasional summer watering and are adaptable to many soil conditions. Yarrow is a tough and robust plant and needs little maintenance (Bornstein et al 2005; Ritter 2018). Yarrow blossoms are important for butterflies and bees, and the leaf foliage provides winter foliage for birds and mammals. Yarrow is also a larval food for some species of butterflies and moths (calscape.org; cnps.org; xerces.org).

Coyote Mint
Monardella villosa

Coyote mint is an evergreen sub shrub that will grow to be about 2 feet high.  They can blossom any time from spring into fall with dense lavender-pink-purple blossoms which have a minty fragrance.  Monardella villosa prefers full sun or part shade with well-drained soil. This plant is easy to grow but does not like to be overwatered. However, occasional summer irrigation will maintain a fresh appearance. Prune back lightly after flowering for fuller growth. Its compact size makes for a great walkway or border. Coyote mint are very attractive to butterflies and other insects (Bornstein et al 2005; Smith, N 2006).

Howard McMinn Manzanita
Arctostaphylos ‘Howard McMinn’

‘Howard McMinn’ manzanita is an evergreen shrub and will grow to be between 5-8 feet tall. Manzanitas are a main component to California chaparral and there are 48 species of manzanita in California. It is known for its smooth dark red bark and bright shiny green leaves. In spring, clusters of white-pink flowers turn into reddish-brown berries. This shrub prefers full sun but can tolerate partial shade and can be cultivated successfully on light or heavy soils. Can be used as an informal hedge and is very attractive to pollinators such as bees and hummingbirds (Bornstein et al 2005, Smith, N 2006).

Summer-Fall Flowers

California Fuchsia
Epilobium canum

California fuchsia is a sub shrub perennial herb and known for its glorious scarlet flowers in summer and fall. This plant is easily grown and will flower most abundantly if placed in a sunny site and will tolerate variety of soil conditions but needs well drained soil. Mature plants are drought tolerant however they will have more lush growth if given some supplemental summer water. Prune back for to make room for spring growth. The flowering period of California fuchsia coincides with the southern hummingbird migration and is a very important source of nectar to hummingbirds and butterflies (Bornstein et al 2005; Smith,N 2006; Calscape.org).

California Goldenrod
Solidago californica

This semi-evergreen herbaceous perennial will reach between 1 and 4 feet tall and is in full bloom and covered with golden yellow blossoms during the summer and fall. This plant needs sun or part shade and can tolerate a variety of soil conditions. Provide the plant with occasional deep watering for spectacular bloom. This plant is an essential to a habitat garden as it provides late summer and fall nectar and it is loved by butterflies, bees, birds and other beneficial insects (Bornstein et al 2005; calscape.org).

California Aster
Symphyotrichum chilense

This Evergreen herbaceous perennial grows to be 1-4 feet tall and blooms in the fall with colorful daisy-like flowers of blue lavender with yellow centers. Place these plants in the sun or part shade with moist and well-drained soil. Deadheading throughout the flowering season will improve appearance. Occasional watering is preferable, but these plants are drought tolerant. Aster is an important late season pollinator plant and serves as a host plant for butterflies and moths, as well as a source of nectar for butterflies, bumblebees, bees, and other beneficial insects (Bornstein et al 2005; Calscape.org).

California Buckwheat
Eriogonum fasciculatum

This plant is an evergreen shrub rarely reaching 4 feet in height. It needs a mostly sunny site in the garden but will tolerate part shade and requires well-drained soil. This plant produces long-lasting cream-colored flower heads and blooms in late spring into summer and sometimes extends into fall. As the flower heads mature in the autumn, seeds develop and provide the landscape with a coppery-rust brown color. The branches are very brittle and can break easily, so it is important to plant it where it won’t be bumped by foot traffic. California Buckwheat is a fantastic addition to the habitat garden, as this plant is a host plant and nectar source for butterflies and moths and is adored by bees as a source for nectar. As the plant matures, it produces seeds, which are an important food source for birds and other mammals and the evergreen shrub provides shelter for wildlife (Bornstein et al 2005; Smith,N 2006; Ritter 2018)

Want to learn more? Here are some helpful resources!

Xerces Society for invertebrate Conservation

California Native Plant Society 

UC Davis Arboretum and Public Garden

UC Master Gardeners

Calscape

Bornstein, B., Fross, D., O’Brien, B. (2005) California Native Plants for the Garden

Ritter, M. (2018) California Plants

Smith, N.M. (2006) Native Treasures. 

References:

Adamson, N., Borders, B., Cruz, J., Folz, S., Gill, K., Hopwood, J., Lee-Mader, E. Minnerath, A., Vaughan, M. (2017) Pollinator Plants California, Xerces Society for Invertebrate Conservation,

Accessed April 22, 2019 from https://xerces.org/pollinator-conservation/plant-lists/pollinator-plants-california/

Arathi, H.S. (2018) Creating Pollinator Habitat, Colorado State University Extension, Accessed July 15, 2019 from https://extension.colostate.edu/docs/pubs/insect/05616.pdf

Bauer, N. (2017), Habitat Value of our Gardens, California Native Plant Society, https://www.cnps.org/gardening/habitat-value-gardens-5261

Bornstein, B., Fross, D., O’Brien, B. (2005) California Native Plants for the Garden, Los 

Olivos, California, Cachuma Press

Hoffman, S., Shepard, M., Vaughan, M., LaBar, C., Hodges, N. (2009) Pollinator Conservation Strategy, Accessed July 19, 2019 from, https://www.xerces.org/wp-content/uploads/2010/01/yolo-nhp_pollinator-strategy_xerces.pdf

Kremen, C., Bugg, R., Nicola, N., Smith, S., Thorp, R., Williams, N., (2002) Native Bees, Native Plants and crop pollination in California, Fremontia, Volume 30:3-4

Kumar, A. (2010) Bee-friendly gardening, Accessed April 22, 2019 from  https://www.cnps.org/gardening/bee-friendly-gardening-2892,

Marks, R., Pauline, R., Maslinek, M., Rewa, C., Winter, K., Shepard, M., Holy, D., Buchmann, S. (2005)Native Pollinators, Wildlife Habitat Management Institute, Natural Resource Conservation Service, Number 34

UC DAVIS Gardening for Pollinators, 2019, Accessed April 24, from

https://arboretum.ucdavis.edu/pollinator-gardening

Ritter, M. (2018) California Plants, San Luis Obispo, California, Pacific Street Publishing

Smith, N.M. (2006) Native Treasures. Berkeley and Los Angeles, California, University of California Press

Ponder, M., Frankie, G., Elkins, R., Frey, K. Coville R., Schindler, M., Guerrero, S., Pawelek J., Shaffer, C. (2013) How to Attract and Maintain Pollinators in Your Garden, http://anrcatalog.ucanr.edu

Calscape, California Native Plant Society

https://calscape.org

Xerces.org, 2016, Four Principles to help bees and butterflies, pollinator Conservation, Xerces society for Invertebrate conservation, Accessed July 22, 2019 from, https://www.xerces.org/wp-content/uploads/2016/10/4Principles-PollinatorConservation_Feb2016_print.pdf

Reel S, Accessed July 15, 2019 from, https://www.fs.fed.us/wildflowers/pollinators/documents/AttractingPollinatorsV5.pdf

Nwf.org. Plant and Create pollinator habitat Gardens, National Wildlife Federation, Accessed July 15, 2019 from, https://www.nwf.org/garden-for-wildlife/about/national-initiatives/plant-for-pollinators

Great pollinator project (2014) Major threats to pollinators, Accessed July 22, 2019 from,

http://greatpollinatorproject.org/conservation/major-threats-to-pollinators