Plants for pollinators, birds and biodiversity 

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Nepeta is attractive to many insects and is also a low maintenance perennial.


Selecting herbaceous annual and perennial plants to enhance biodiversity in the landscape.

There is a lot of interest in making our landscapes more sustainable and using them to provide ecosystem services such as providing food and habitat for pollinators and birds. 

Although this is of course nothing new, the renewed interest is a good thing in both urban and suburban environments where landscapes are often not very diverse or welcoming for pollinators or birds. Wind pollinated trees and shrubs and mowed turf provide little forage or habitat and habitat destruction is one of the factors being blamed for a decline in pollinator populations along with diseases and pesticides. 

Appropriate plant choices for landscape plantings can enhance biodiversity in our urban areas by increasing foraging opportunities and providing appropriate habitat while meeting our need for attractive and manageable landscapes.



One common approach to increasing biodiversity in the landscape is through the increased use of native plants. 

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Tithonia is not native to Pennsylvania but is an attractive garden plant and is attractive to pollinators.

The argument usually goes something like this.. native plants in a region provide these services to the native bird and pollinator populations and have done so for a long time. When we replace the natives or displace them we are removing resources needed by the species that rely on these plants. 

This is a reasonable approach, as far as it goes, and the use of native species should be encouraged. 

One can of course also select adapted introduced species that can, and do, provide the same ecosystem services and there is no logical reason to limit the plant pallet to native species in a butterfly or bee garden unless you are specifically also planting a “native” landscape. 

It is far more important that you provide a variety of food and shelter options and that you provide forage throughout the active annual cycle for the species you are supporting. 

You might plant a very nice native garden with a limited number of fall blooming species. While this may be attractive to pollinators in the fall it does not provide food resources the rest of the year and is thus of lower biodiversity value than a garden of all introduced species that bloom throughout the warm seasons.

Several species of Pycnanthemum (Mountain Mint) are native to Pennsylvania. Mountain Mint is very attractive to pollinators when it is in bloom in August and September.


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Sunflower (Helianthus annuus) is like many plants int the Asteraceae, very attractive to pollinators. It is also attractive to birds after it has set seed.

Several plant families have many members that are very attractive to pollinators. Fortunately there are also many outstanding garden plants represented in these groups as well.

Asteraceae

Most plants in the Aster, or composite, family are good biodiversity plants. Examples include Asters, Echinaceae, Rudbeckia, Tithonia, Helenium, Helianthus and many others. 

The broad diversity of plant genera and species in this family provides opportunities to have flowering throughout the warm season and diversity in flower color, size and plant size and form. Insect biodiversity is enhanced by plant biodiversity, so it is more beneficial in a pollinator garden to have many plants of differing characteristics, than to have a limited selection of very attractive plants.

Helenium autumnale is a good example of a native plant in the Aster family that makes a good pollinator garden plant.

There are several native Eupatorium species that are attractive to pollinators. Pictured above E. perfoliatum (Common boneset) has white flowers in the late summer or early fall and Eutrochium purpureum (aka Eupatorium purpureum, Joe Pye Weed) has rose colored flowers in the late summer.

Not all cultivars of a pollinator friendly genus or species are equally attractive to pollinators. For example while Echinacea purpurea and many of the new hybrid Echinacea cultivars are good pollinator garden plants, the doubled forms, pictured above, are far less attractive to pollinators and are thus far less useful in a pollinator garden. This is true for most doubled flowers of plants in the Asteraceae. They may be very interesting and attractive garden plants but because of the modified flower structure associated with doubling they do not provide the rewards provided by single flowered  cultivars.

Plants that are attractive to desirable insects may also be desirable to pest species. In the photo above Japanese Beetle are feeding on an echinacea flower. Pest management in a biodiversity garden may be more difficult than in plantings not managed to promote biodiversity. Pesticide use should be minimized and materials used and application timing managed to reduce collateral damage to non-pest species.


Lamiaceae

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Agastache has a long bloom period and is very attractive to many pollinator species

Another family with real pollinator appeal, the Lamiaceae also has many excellent garden plants with outstanding ornamental value, and quite a few native or adapted species. For example most of the ornamental salvia species and cultivars make good pollinator garden plants.

Pycnanthemum (Mountian Mint) is very attractive to a wide range of pollinator species. Agastache is also a very useful pollinator garden plant, and many of the salvia’s are also good pollinator garden species. 

Many of the herbs in the lamiaceae are not only useful in an herb garden but are also excellent pollinator garden plants. For example Lavendula (pictured below) will attract many species of pollinators and has a very long bloom period.

Apiaceae

The apiaceae contains many plants that not only attract pollinators but also many beneficial insects. These plants are often used as companion plants, placed in the garden specifically as hosts for beneficial insects which then prey upon other insect pests.

Eryngium, pictured above, is a good example of a useful biodiversity garden plant in the Apiaceae. 

There are many other plants that are suitable for use in a biodiversity garden. Many of these also have the advantage of having sweet scents intended of course, to attract insects, but also useful in a planned and managed landscape. Heliotropium (pictured below) is a late season blooming plant with sweet smelling flowers that are attractive to pollinators.

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Monarch larvae on asclepias

Sedums are frequently included on lists of pollinator friendly plants. Different sedums bloom at different times of the year so a mix of sedums on a green roof can provide forage for pollinators through much of the growing season. 

It is important to remember that if you want to attract butterflies to a garden you not only need to provide food for the adults but also food for the larval forms. For example, Asclepias is the host plant for monarch larvae and as such should be included in a garden intended to attract butterflies 



Exercise: Complete this exercise in the Week 5 module of the class Canvas website


Using the plants we have studied to date in this class:

  1. Develop a list of plants for an all native pollinator garden for a mostly sunny location in State College. Include 9-12 species and remember to consider bloom times to provide food throughout the spring, summer and fall.
  2. Develop a list of plants including native and introduced garden species for a butterfly garden in a sunny location in State College. Include at least 5-9 species. The client also wants this garden to serve as a cut flower garden for the house.
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