Planting for Pollinators

Planting for Pollinators

Butterflies, bees, and more!

Written for the Davis Enterprise, June 19 2014

Bees and monarchs in the news

    I'm always happy to see stories about particular pollinator species in the news. Curious, perhaps, that the non-native European honeybee sparks so much

    concern, while the status of the 4,000 or so species of native bees gets very little attention.

    But what's good for one pollinator can help others, and gardeners are taking an interest. So that's great. And there are lots of other types of

    pollinators, including butterflies and hummingbirds, that will happily visit your garden if you provide the right plants and conditions.

    First principle is to have lots of different plants flowering over all seasons. A bunch of mixed perennial and annual flowers will be more effective than,

    say, a garden solely of rose bushes.

    Second principle is to retain some dense, kind of overgrown areas, include some grass species, and have some open uncultivated soil to provide for the

    different stages of the life cycles of pollinator species.

    Finally, provide some simple water sources, and reduce your use of pesticides.

    What you want to provide is at least three or four types of plants blooming at all times, some nearby shrubs and larger plants where wildlife can rest,

    nest, and feed.

    Grasses help to provide habitat and hiding places for beneficial insects. Soil that you leave undisturbed can provide nesting sites; many of our native

    pollinators live in burrows in the ground. This all can be very low water. Deep, infrequent soakings are best for most of the plants listed.

   

Here are some garden plants for pollinators, by season of bloom.

 All of these are easy to grow and drought tolerant. Note that a number of common kitchen

    herbs draw pollinators. (CN) = California native plant.

    Early bloom season:

    Borage (Borago)

    Golden bush daisy (Euryops)

    Pride of Madeira (Echium)

    Early to mid season:

    Cape mallow (Anisodontea)

    Lavender (Lavandula)

    Lupine (Lupinus)

(CN)

    Penstemon (CN)

    Poppy, California (Eschscholzia)

(CN)

    Sage (Salvia)

(CN)

    Mid season:

    Anise hyssop (Agastache)

    Basil (Ocimum)

    Buckwheat (Eriogonum)

(CN)

    Catmint (Nepeta)

    Cosmos

    Mint (Mentha)

    Oregano (Origanum)

    Penstemon

    Pincushion flower (Scabiosa)

    Russian sage (Perovskia)

    Sage (Salvia)

    Thyme (Thymus)

    Yarrow (Achillea)

    Late season:

    Aster (Aster

species) (CN)

    Blue mist (Caryopteris)

    California fuchsia (Epilobium)

(CN)

    Goldenrod (Solidago)

(CN)

    Rosemary (Rosmarinus)

    Sunflower (Helianthus)

    Many landscape shrubs have flowers that attract pollinators. Examples include native shrubs such as toyon (Heteromeles)

and wild lilac (Ceanothus), as well

    as tough non-natives such as Xylosma

, butterfly bush (Buddleia), and even the lowly privet. All will draw and sustain native bees, honeybees, and other

    pollinators into your landscape.

   

Food for butterflies?

    The precipitous decline of the beautiful Monarch butterfly in its Mexico overwintering sites has received a great deal of media attention. Most media

    sources are attributing that sudden drop in population to loss of habitat and food sources in the midwest. The populations that overwinter in coastal

    California appear to be more stable, though at a low ebb.

    Various publications and organizations are urging you to plant milkweed (Asclepias

species), because that plant is the sole food source for Monarch

    caterpillars. Consequently, wholesale nurseries are selling out of Asclepias as fast as they can grow it. Good news: Asclepias is very, very easy to grow.

    Some types have very showy flowers which attract butterflies of various species in addition to the Monarch. You can easily grow milkweed to draw adult

    butteflies, but it may become a larval food source, which means that you will need to tolerate caterpillars eating your plants.

    There are several dozen species of milkweed, all of which appear to be possible food sources, but only a handful are actually common in the trade. A few

    examples:

   Asclepias speciosa,

Showy milkweed, is a California native with soft pink flowers and grey foliage, so the whole effect is subtle and elegant. It can get to about four feet

tall and is rather robust and perennial.

Asclepias fascicularis,

Narrowleaf milkweed, is a California native with narrow green leaves and white (very, very pale pink) flowers. It is very adaptable as to soil and

watering, but less showy than other species.

Asclepias curassavica,

Tropical milkweed, is a species from South America with very bright red-and-yellow flowers against a dark red-green foliage, so it is is one of the most

attractive of the garden milkweeds. Being tropical, it doesn't overwinter here. There are some solid-color forms available. This species has become common

in the nursery industry because it is very attractive, blooms at an early age, and has a compact habit.

Asclepias tuberosa,

Butterfly weed, is native to moist areas of the eastern U.S., and is often sold for planting near ponds. The species has bright orange flowers; and there

are varieties with mixed colors. Long-lived but slow to begin flowering.

    There is a common misperception from various online sources that native species of Asclepias are preferred as food sources. The issue is that the milkweed,

    which contains cardiac glycosides, renders the caterpillars poisonous and repellent to birds, which then avoid them.

    So does a larval food source from a non-native species make the caterpillar more subject to predation? I asked our resident butterfly expert, Dr. Art

    Shapiro, who replied that “native species are neither necessary nor preferred. As it happens, curassavica is quite potent--more so than any of our common

    natives. Tropical and subtropical species are generally quite potent, as are species from desert environments and on harsh soils.”

    There is a species of orange aphid that always seems to show up on milkweeds. It also just seems to disappear, prey to various beneficial insects and

    birds. So you can just leave it alone, or wash it off with water if it bothers you.

   

Some other plants to feed butterfly larvae.

    There are two other plant/caterpillar relationships that gardeners may try to cultivate (pun intended). The caterpillar of the Gulf fritillary butterfly

    feeds on the foliage of some species of passionflower (Passiflora

). Passifloras are vigorous vines that range in hardiness and degree of

    garden-invasiveness (ask!), and the occurrence of the caterpillars is pretty haphazard. But the blooms are incredible, some having a spicy scent, and they

    draw various native bees for pollination.

    Pipevine swallowtail, a native butterfly species, is attracted to many different flowers for pollination. But its larvae exclusively feed on native

    pipevine (Aristolochia californica

). The relationship is similar to the monarch butterfly: the pipevine contains toxins that make the caterpillar

    unpalatable to predators. Most nurseries grow hybrid pipevines, as they are easier to propagate and have showier flowers. But they won't act as food

    sources.

    Another oddity about pollination: Aristolochia californica

, like many other pipevine species, is pollinated by insects that feed on carrion. How

    does a flower draw carrion flies and gnats? By smelling like rotten meat. I have found this limits the sales appeal of this species. The last time we had

    one in stock, we spent a couple of days looking for the dead animal before we realized where the odor was coming from.

    One of the great pleasures of my job is being greeted each morning by a panoply of interesting and unusual flowers, and watching the insects and birds that

    visit them. We provide a mix of blooming plants, simple water sources, and we manage pests naturally. Even in a limited space you can do the same, and

    watch bees, butterflies, and hummingbirds visit your garden daily, year-around.

The showy flowers of Asclepias curassavica

, the tropical milkweed, and its compact growth habit have made it popular with gardeners and wholesale growers. This species is tender, so is replanted each year. The flowers draw butterflies and bees; the foliage can feed Monarch caterpillars.  

Asclepias speciosa

, Showy milkweed, is a California native with soft pink flowers and grey foliage, so the whole effect is subtle and elegant. It can get to about four feet all and is rather robust and perennial. Excellent addition to a drought-tolerant landscape. Photo courtesy of Nevin Smith, Suncrest Nurseries

 Butterfly bushes are aptly named. These very popular garden shrubs have, until recently, been large and somewhat rangy things for the back of the border. New dwarf hybrids are now available that stay under five feet tall, and are also sterile so they don't reseed. 

A recent morning's visitor, this pipevine swallowtail spent much of the morning visiting buddlieas, salvias, cosmos, and other flowers. A diversity of colorful blossoms over a long season keeps butterflies coming to your garden. 

The origin of the common name of pipevines is obvious. This hybrid is readily available, but unfortunately is not fed upon by the native pipevine swallowtail. And the strange flowers are quite malodorous. 

Passiflora

 blossoms are very showy, some are almost unearthly. This variety called Purple Tiger has a spicy fragrance and looks, as one boy put it, like a space alien jellyfish. Our native carpenter bees love the flowers. 

Passion flower vines are vigorous and bloom abundantly. Some types act as food sources for the Gulf fritillary caterpillar (which means you will have to tolerate watching them eat your vine). All passionflowers attract various of our native bee species. This carpenter bee was so intoxicated that she stayed basically immobile for about three hours. Sugar high, I guess. 

Closeup of this Salvia flower (variety: Dark Dancer) shows the unique pollination mechanism. A nectar reward at the base of the flower tube draws butterflies, bees, and hummingbirds. Inside the flower, following the curve of the petal, is an anther bearing pollen, which is deposits on the back of the unsuspecting bee. The part poking down from above is the stigma (female part) which receives the pollen that the bee picked up at the last flower. 

Age Appropriate Gardening Activities

Gardening with kids

    I want to thank my Facebook-friend Christine for inspiring this column. She posted a great list of Age-Appropriate Chores for Children, and the thing I

noticed was how few of them were gardening activities. Other than 'weed garden, rake leaves, mow lawns, trim hedges', there wasn't much to get kids outside

and active in the yard. And none of those sounded like much fun. So I thought I'd add to the list she found.

First, a couple of pet peeves of mine.

    One: if it's in the garden, please don't call it a chore.

    Two: those are all maintenance and cleanup tasks with little intrinsic reward. A clean, orderly yard is a grown-up goal (and rather over-rated, IMO). How

about 'plant some flowers for grandma' or 'put straw in the strawberry patch to keep the fruit away from the slugs'?

    The second spark for this topic was a picture I found. I've been sorting through some of my mom's snapshots, and, lo and behold, there I was at age 11,

standing on the garage roof with my 14-foot-tall sunflower plant, hoisting the 2-foot-diameter flowerhead, with a look of mild astonishment on my face.

That was probably the year my father got a real deal on a dumptruck load of manure, which prompted vigorous growth. But I did the planting and watering.

    My parents were seriously good gardeners. In retrospect, they were also very good at cultivating young gardeners. Spark an interest, let the youngster pursue it, and support it at appropriate levels.

    So here are some suggestions for the young would-be gardeners in your life. I have no background in childhood development. These are just based on my observations and experiences as a gardener and parent, and from interacting with kids at my shop and in garden projects over the years. Obviously, adult supervision is required for many of these things. You don't turn your 12-year-old loose with a string-line trimmer without safety and usage training. Or your 42-year-old, for that matter.

    Ages 2 - 4

    o Choose flower colors.

    o Collect and kill snails.

    o Harvest tomatoes.

    o Plant large seeds.

    o Water with a watering can.

    Plants of special interest: fast-growing seeds, big juicy fruits.

    The first garden 'chore' that I can remember was picking snails and putting them into milk cartons. My mother would dispatch them with salt. A few hours in

    the freezer will also do the trick, if you're squeamish. I got paid a penny for every two snails.

    Big seeds that are easy to handle and grow: nasturtiums, sunflowers; beans, peas (plant in fall), corn, squash.

   

Ages 5 - 8

    o Choose vegetable and herb plants.

    o Dead-head annual flowers.

    o Harvest beans and peas.

    o Harvest berries.

    o Hunt for caterpillars.

    o Make a flower arrangement.

    o Plant a color bowl.

    o Plant a terrarium or dish garden.

    o Plant flower bulbs.

    o Plant seeds in small pots.

    o Plant seedlings into the garden.

    o Pull annual weeds.

    o Rake leaves.

    o Remove spent rose blossoms.

    o Transplant young seedlings into larger pots.

    o Trim small shrubs.

    o Water with a hose and nozzle.

    Plants of special interest: annual flowers, vegetables and herbs, scented plants, flowers for butterflies and hummingbirds.

This is the golden age for gardening! Disillusionment from failure has not yet set in. When I was about six my mother let me select some flower seeds. I chose coleus for the gaudy colored leaves, and fibrous begonias. In hindsight, begonias were a pretty tricky choice: the seed is as fine as dust. But we got them started, grew them up, and planted them with care out in a side garden bed. And then I promptly lost interest in gardening.

Two or three years later, I came upon the little plants, still growing and blooming, lost among the weeds I was pulling. A couple of years is a lifetime at that age; it seemed like a tremendous thing to find. And it restored my interest in gardening.

At about 8, my daughter wanted to grow roses to sell bouquets. She chose the varieties, we planted them together. The interest passed, but the roses are still there as lovely reminders.

Fall and winter planting of flowerbulbs can be a simple project with younger gardeners. In California we are fortunate to be able to plant warm-climate narcissus that sprout and bloom right away, even indoors, so kids see quick results. After the bloom, just plant them out in the garden where they'll spread freely and bloom year after year.

    Easy annual flowers: alyssum, borage, cosmos, forget-me-nots, four-o-clocks, hollyhocks, nasturtiums, and zinnias.

  

  Ages 9 and up

    o Choose fruit trees and landscape plants

    o Choose plants for a theme garden.

    o Cut back herbaceous perennials.

    o Dig out perennial weeds.

    o Divide perennials.

    o Harvest melons.

    o Hoe weeds.

    o Make a bonsai.

    o Manage aphids.

    o Mow lawns.

    o Plant a tree.

    o Put in a drip watering system.

    o Repot an orchid or houseplant.

    o Start a compost pile.

    o Trim a shrub.

    o Turn soil and add compost.

    Plants of special interest: bonsai, cactus and succulents, carnivorous plants. Fruit trees, giant vegetables, herbs and scented plants.

Pre-adolescent gardeners can learn about quality and care of gardening tools. They can understand the lifecycles of important pests and beneficial wildlife

in the garden. And they are generally better able to synthesize and implement complex gardening projects than we give them credit for.

   

 Ages 12 and up

    o Choose trees.

    o Create a topiary.

    o Design and plant a small vegetable and herb garden.

    o Plant for beneficial insects and wildlife.

    o Prune fruit trees.

    o Prune roses.

    o Use a stringline trimmer.

    Plants of special interest: native plants, orchids, organic and sustainable gardens, special pollination adaptations, subtropical and tropical plants, unusual fruits.

    When I was about 13, my father and I built a simple windowbox. Cast-off orchids from my grandfather, dish gardens from the lady next door, and all manner of interesting tropical plants filled it quickly. It was a simple project, appropriate to my level at the time.

    Ages 15 and up

    o Build a raised planter.

    o Control pests.

    o Install, repair water systems.

    o Maintain a lawn mower.

    o Rototill a garden and amend soil with compost and fertilizer.

    o Stake a tree.

    Plants and practices of special interest: hydroponics, medicinal herbs, plants used in food and beverage production (olives, hops, grapes, tea), symbolic plants, unique growth habits, weird plants from strange places.

 At 15, my parents ceded a whole portion of our yard to me to do with as I liked. A special gardening allowance - not much, but enough to merit a monthly visit to a garden center - was established. My father and I built a simple greenhouse (mom wouldn't let me use hers), which filled up quickly. At 16, my son developed an interest in Norse traditions, so we planted a special group of trees with that theme: birches and yews. Seven years later, it's a lovely stand that has special meaning to him.

    Please, never refer to gardening as a matter of luck -- good, bad, or otherwise. All plants need four things to live: light, air, water, and nutrients. Some need protection from pests or weather. Learning to garden is simply learning how individual plants vary with regard to these basic needs, and providing them. It's really that simple.

    Examples:

    o Cactus like dry soil, ferns like moist soil.

    o Carnivorous plants can't tolerate water that contains salts.

    o Azaleas need a low soil pH, so they don't grow well in Davis.

    o Tropical plants will die outside in the winter if they aren't protected.

    o Snails will eat your hostas before they'll eat your lobelia.

    And so on. Good gardeners have accumulated a lot of information from their experiences. You can acquire that knowledge from books, mobile phone apps, the folks at the garden center, that lady down the block with the incredible yard, or your parents. Or trial and error (empirical research, we call that).

Buy a bag of manure, plant some sunflower seeds together, and see where it leads!

A blurry snapshot from 1968, saved by my mother. Standing on our garage roof next to my fourteen foot tall sunflower plant. The flower head measured more than two feet! 

Flower seeds that are easy to grow make gardening successful and fun for younger gardeners at very low cost. Borage is an herb plant with a pleasant cucumber smell. It's grown as much for the flowers as it is for the leaves; the pretty blue blossoms continue nearly year-around and draw honeybees. The plant reseeds happily throughout your garden beds.

Direct-seeded or transplanted into warm soil, cosmos is one of the easiest summer flowers to grow. Very suitable for young gardeners. Ferny foliage, bright flowers; the blooms start in mid-summer and continue until frost. Just wait until about May to start planting cosmos.

Save this project for next fall or winter. Members of the tazetta group of narcissus are easy to grow. Unlike other bulbs, they sprout right away when planted, even indoors in a sunny window. The powerfully fragrant flowers show up 8 to 10 weeks later. When they're done flowering, you can just plant them in any sunny place in your yard. They'll multiply freely. Shown here is the variety that is called Chinese Sacred Lily. 

Starting plants from seeds can be done with young gardeners with some supervision. Use larger seeds with the youngest kids. One note of caution: some of the soil amendments used for seed-starting can cause skin irritation. It's important to train gardeners of all ages to wear gloves when handling soils.

As gardeners grow in age and sophistication, they can plan and plant gardens toward specific purposes. Two popular themes are attracting butterflies and hummingbirds, and there are lots of very easy-to-grow plants for each. Shown here is a swallowtail butterfly alighting on a Butterfly bush (buddleia). New dwarf buddleias (including varieties that don't reseed) make this a simple choice for smaller yards, or even containers. 

Lots of kids get interested in carnivorous plants, but they do have special needs. They need pure water, you never fertilize them, and they require special soils. And you need to understand their lifecycles, including winter dormancy. There are easier carnivorous plants than the well-known venus flytrap. But, as with bonsai and orchids, a little homework and consultation with experts can lead to success.

That interesting school project your child pursues can lead to beautiful landscape changes. The birches and yews we planted several years ago in response to my son's studies of Norse traditions have now grown to create a lovely little sanctuary on one corner of the property. Beautiful fall color! You never know where your child's gardening interests may lead.