Monday, June 17, 2019

Pollinator Garden Basics

A Green-Headed Coneflower provides nectar for multiple Sweat Bees, a Bumblebee, and Orange Mint Moth.

     There are over 200,000 species of pollinators worldwide. These include such diverse animals as bees, wasps, butterflies, moths, flies, beetles, and hummingbirds. We owe them much, as it is often said that one out of every three bites of food we enjoy is due to the direct actions of an animal pollinator. In fact, three-quarters of all plants, regardless of whether we eat them or not, depend on animal pollinators in order to reproduce. There are many basic things we can do to make our gardens and landscape more pollinator friendly:

      Avoid using pesticides and/or herbicides.

      Plant for continuous blooms throughout the seasons (so you have continuous food).

      Use mass plantings (they’re easier to see by pollinators flying by)

      Include host plants for caterpillar and oligolectic plants for bees (the native plants 1/5
        of our native bees evolved with and need in order to reproduce).

      Provide basking sites (they all need to warm up).

      Consider wet mud spots to serve as puddling areas for butterflies, mud plots for
         mason bees/wasps.

      Try to locate your garden in the sunniest location you have for the most blooms.

      Consider flower color & shape (white, yellow or blue composite flowers are often

      Avoid double-flowered or other cultivars (cultivars are chosen for traits people want; 
   evolution chose what the pollinators want).

     Leave old stalks, if not diseased, to overwinter. If you can cut stalks to a foot or so
        high and leave them for the new growth to grow over, you can provide nesting spots
        for insects such as bees, of which 30% nest in places like old stalks. It will still look
        neat, but provide nesting platforms throughout the year. If you resist the urge to
        clean up and remove fallen leaves, you also provide good habitat.

      Go Native!

A Goldenrod is covered in small pollinators.
Why Choose Natives?
-    They provide more food/shelter for the animals with whom they evolved. 96%
       of terrestrial birds feed their young caterpillars (and sawflies) as their major food source,
       particularly while nesting. All 17 of our bat species feed on insects preferring moths
       (which of course are adult caterpillars).
-    They are preferred by native wildlife (with whom they evolved). Indeed many are
       necessary as host plants for caterpillars and 1/5 of our bees.
-    Given that most insects lay large number of eggs, supplying the plants they need can
       make a big difference locally. Of all the insects that feed on plants, 90% are specialists
       needing the native plants they evolved with, and many of these are pollinators such as
       butterflies and bees.     
-    They are adapted to our environmental and soil conditions in which they evolved.  
-    There are so many to choose from adapted to just about every growing condition (over
       1700 species in NoVA alone).
-    The same plants can have multiple uses (aesthetics, edible landscaping, herbal, wildlife
       gardening, etc.).
-    They are attractive!
     So do your part for pollinators and other wildlife by following these guidelines, most especially by going Native!

A Bumblebee and Monarch Caterpillar share a Swamp Milkweed.

Happy National Pollinator Week!

A Bumblebee, Metallic Sweat Bee, and Orange-Spotted Mint Moth share a meal on a Green-headed Coneflower.

   Happy National Pollinator Week! There are over 200,000 species of pollinators worldwide. These include such diverse animals as bees, wasps, butterflies, moths, flies, beetles, and hummingbirds. We owe them much, as it is often said that one out of every three bites of food we enjoy is due to the direct actions of an animal pollinator. In fact, three-quarters of all plants, regardless of whether we eat them or not ,depend on animal pollinators in order to reproduce.
     When thinking about planting things to benefit our pollinators who benefit us so often, a critical thing to consider is the use of native plants. Studies show that native plants are four or more times more attractive to native pollinators than exotic plants. This, of course, makes perfect sense since these plants and animals evolved together, sometimes to the point that one cannot exist without the other. Many caterpillars for example cannot survive without their specific native host plant to feed on. About one out of every five of our 450 native bees in the Mid-Atlantic area need the specific pollen of certain native plants or they cannot reproduce. Just any flower or plant simply won't due.

A Hibiscus Bee (Ptilothrix bombiformis) digs its nesting hole. While it can visit many flowers, it needs pollen from plants in the hibiscus family or it cannot reproduce.

     So the most important consideration is to plant plants that are locally native. These plants are not only adapted to grow in this type of habitat, but are what the pollinators have been using for thousands of years. It is also always best to use straight wild species, rather than cultivars or nativars which have been selected for certain traits. When we plant a flower that has been bred to appeal to us through a novel color or look, it may not have the same appeal to the pollinator its parent plants originally evolved with. What might be attractive to us may not be attractive to pollinators, some of which see flowers through different spectrums or look for certain traits in them. This is especially true of plants bred to have double flowers or blooms with extra large petals, since they often sacrifice nectar/pollen for the extra showy flowers. To remove any doubt and provide maximum habitat value, go native.

Multiple Great Spangled Fritillaries nectar on Swamp Milkweed, the host plant for Monarch butterflies and 11 other caterpillar species. With 15 species of milkweed alone in Virginia, there's a native one for just about every growing condition, not just swamps.

     Also something to consider are the multiple uses you get with native plants. Many exotic plants may have a pretty flower that may (or may not) provide nectar for a short time each year while blooming, but it otherwise provides little habitat or nutrition for pollinators or other native wildlife. Take the Chinese Aster (Callistephus) for example. It is a pretty flower, comes in many color forms and is widely planted (and has escaped and naturalized into some areas). The blooms on some varieties provide some nectar and pollen to a few pollinators for a short bloom time each year. But only two species of caterpillars have been recorded as feeding on it. It is for the most part and for most of its plant life a barren habitat for wildlife, taking the place of what might have been a much more beneficial native plant.
     Contrast that with one of our many (Virginia alone has 43 different species) colorful and attractive native asters, many adapted to a variety of growing conditions. Now you have flowers that not only provide attractive flowers for the garden and a similar look, but also serve a habitat and food function. In addition to pollinators visiting them, most also supply seeds for birds such as finches and sparrows. But 109 different caterpillar species have also been documented feeding on asters. These in turn feed the vast majority of our nesting native birds (96% of terrestrial birds feed on insects, particularly during the nesting season, most of which are caterpillars) and most of the 18 bat species found in our region (all of which are insectivores and many of which prefer moths over other insects). At least 8 different bee species need their pollen or they cannot reproduce.

A Pearl Crescent nectars on an aster, which also is the only food its caterpillars can feed on.

      So you can see how something as simple as choosing a native plant species can not only serve to provide for pollinators, but then serve many other habitat functions as well. So this National Pollinator Week, enjoy the pollinators in our gardens, farms, and parks. Include locally native plants in your gardens. This way you too can help the pollinators who are always helping us.

A Syrphid Fly, a wonderful bee mimic, pollinating Tickseed Sunflower.

     In Arlington County, we try and make the vast majority of the plants we use natives for all the reasons stated above, it is part of our planting policy. This week serves as the two year anniversary that Arlington County made the Mayor's Monarch Pledge to commit to doing several different things to help monarch butterflies. We of course will continue to do many other things to help monarchs and so many other pollinators. Here's a look at the Bluemont Pollinator Patch one year later during National Pollinator Week in June of 2018:

A pair of Long-Horned Locust Borer Beetles multitasking, feeding, mating and pollinating Goldenrod all at the same time.

     The establishing of Pollinator Patches and Monarch Way Stations is just one way to continue to support pollinator numbers. Please join us in supporting our pollinators by planting native plants when you can and taking pollinator needs in to consideration when you do things at home. 

A Sweat bee and Bumblebee sharing a Wingstem meal.