Native Plants and Invasives
The statistics for wildlife habitat in the lower 48 states are abysmal. 54% of the land is taken up with cities and suburbs. Another 41% of the land is used for agriculture. That leaves a mere 5% for non-human use, for wildlife, native plants and animals.
Native plants are those that were here before the arrival of Europeans. They evolved in this climate and environment and are therefore most compatible with this location. Being well adapted for the amounts of rainfall, the soil quality, other plants, animals, and insects, they need less resources to survive and thrive. Since plants and wildlife evolved together, they are often co-dependant. Many insects need a limited range of specific plants to survive. When invasive plants take over and crowd out native ones, then insects that depend on them don't prosper, and birds that feed on those insects fail, and so on through out the ecosystem. An obvious example is the monarch butterfly. While the butterflies gather nectar from many plants, their caterpillars feed only on the milkweed plant. As humans develop more land for their own use, at the rate of about 2 million acres a year -- about the size of Yellowstone National Park -- milkweed becomes a scarce commodity and monarch numbers decline. This past summer (2023) the Northeastern monarch was officially put on the endangered species list. One obvious solution is to plant more milkweed for the caterpillars.
Another interesting example of this symbiotic relationship between plants and animals is the mayapple and the eastern box turtle. Mayapples are declining, in part because of loss of habitat, and in part because there are fewer eastern box turtles. A very small percentage of the fruit of the mayapple actually germinates on its own. However, the turtles love the fruit and gobble them up. After the seeds go through the turtles' digestive tract a much higher percentage germinate and grow into new plants. But as box turtles disappear, so do new mayapple plants.
Not all non-native plants are invasive. Think of tulips and other spring bulbs which arrived here from the middle east via the Netherlands. Invasive species are ones that spread like crazy, and since they are not native they often have few if any enemies, giving them an advantage over native plants. We've all enjoyed sucking the sweet nectar out of honeysuckle flowers, but these fast spreading climbers from Japan quickly crowd out native plants. Loosestrife, beautiful as it is, is another example of an invasive, one that clogs our waterways and wetlands.
A relatively new and dangerous threat is garlic mustard that not only out-competes local plants for resources, but actually secretes chemicals into the soil, making it toxic to natives. In addition it is poisonous to caterpillars reducing butterfly populations. Garlic mustard is a biennial; the first year it forms clumps of round slightly wrinkled leaves that smell somewhat like garlic. The second year the plants grow up to 4 feet tall and produce small clustered white flowers with four petals, blooming in mid- to late-spring. Spring is the easiest time to pull the plants which should be bagged and disposed of, not composted. Alternatively, one could eat them! Invasivore.com is a website devoted to recipes for many different invasive species. [ http://www.invasivore.org ]
Here in Pennsylvania over a third of all plant species are invasive. So we as gardeners should be mindful of what we plant and aim for native species as much as possible. One of the goals of The Jenkins Arboretum in Devon, PA is to educate people about the use of native plants. [ http://www.jenkinsarboretum.org ] Another source is Bowman's Hill Wildflower Preserve [ http://www.bhwp.org ] which has a native plant sale in May.
The statistics for wildlife habitat in the lower 48 states are abysmal. 54% of the land is taken up with cities and suburbs. Another 41% of the land is used for agriculture. That leaves a mere 5% for non-human use, for wildlife, native plants and animals.
Native plants are those that were here before the arrival of Europeans. They evolved in this climate and environment and are therefore most compatible with this location. Being well adapted for the amounts of rainfall, the soil quality, other plants, animals, and insects, they need less resources to survive and thrive. Since plants and wildlife evolved together, they are often co-dependant. Many insects need a limited range of specific plants to survive. When invasive plants take over and crowd out native ones, then insects that depend on them don't prosper, and birds that feed on those insects fail, and so on through out the ecosystem. An obvious example is the monarch butterfly. While the butterflies gather nectar from many plants, their caterpillars feed only on the milkweed plant. As humans develop more land for their own use, at the rate of about 2 million acres a year -- about the size of Yellowstone National Park -- milkweed becomes a scarce commodity and monarch numbers decline. This past summer (2023) the Northeastern monarch was officially put on the endangered species list. One obvious solution is to plant more milkweed for the caterpillars.
Another interesting example of this symbiotic relationship between plants and animals is the mayapple and the eastern box turtle. Mayapples are declining, in part because of loss of habitat, and in part because there are fewer eastern box turtles. A very small percentage of the fruit of the mayapple actually germinates on its own. However, the turtles love the fruit and gobble them up. After the seeds go through the turtles' digestive tract a much higher percentage germinate and grow into new plants. But as box turtles disappear, so do new mayapple plants.
Not all non-native plants are invasive. Think of tulips and other spring bulbs which arrived here from the middle east via the Netherlands. Invasive species are ones that spread like crazy, and since they are not native they often have few if any enemies, giving them an advantage over native plants. We've all enjoyed sucking the sweet nectar out of honeysuckle flowers, but these fast spreading climbers from Japan quickly crowd out native plants. Loosestrife, beautiful as it is, is another example of an invasive, one that clogs our waterways and wetlands.
A relatively new and dangerous threat is garlic mustard that not only out-competes local plants for resources, but actually secretes chemicals into the soil, making it toxic to natives. In addition it is poisonous to caterpillars reducing butterfly populations. Garlic mustard is a biennial; the first year it forms clumps of round slightly wrinkled leaves that smell somewhat like garlic. The second year the plants grow up to 4 feet tall and produce small clustered white flowers with four petals, blooming in mid- to late-spring. Spring is the easiest time to pull the plants which should be bagged and disposed of, not composted. Alternatively, one could eat them! Invasivore.com is a website devoted to recipes for many different invasive species. [ http://www.invasivore.org ]
Here in Pennsylvania over a third of all plant species are invasive. So we as gardeners should be mindful of what we plant and aim for native species as much as possible. One of the goals of The Jenkins Arboretum in Devon, PA is to educate people about the use of native plants. [ http://www.jenkinsarboretum.org ] Another source is Bowman's Hill Wildflower Preserve [ http://www.bhwp.org ] which has a native plant sale in May.
A newly-emerged black swallowtail butterfly.
Its chrysalis is in the background.
Butterfly Gardens
The Community Garden Club at Wayne has now undertaken a new project — that of maintaining the Bird and Butterfly garden on the Radnor Trail opposite the Wayne Art Center dedicated to Elizabeth Chew Bennet, a life-long Radnor resident.
Butterflies are fascinating insects, and following their life cycle is intriguing. Creating and maintaing a garden for them is not only beautiful but also good for the environment. Butterflies play an important role in pollinating flowers, but due to insecticides, loss of habitat, and the introduction of more exotic plants, their numbers are decreasing. For instance, there are fewer monarch butterflies east of the Mississippi, in part due to fewer and fewer milkweed plants. With more housing, shopping centers, and other encroaching civilization, wild areas with abundant milkweed disappear. Monarchs only lay their eggs on milkweed since that is the only food their caterpillars eat. In fact, all caterpillars are very particular about what they eat and have very limited diets. A butterfly garden must, therefore, not only have flowers full of nectar for the adults, but host plants for their offspring.
Some of the requirements for a good butterfly garden include lots of sun, as well as sheltered areas to protect the insects from wind, cluster plantings of both nectar flowers and host plants, perhaps some rocks for the butterflies to rest on and enjoy the sunshine, wet patches or puddles, and of course, minimal or no use of pesticides.
Nectar plants are quite numerous. Butterflies generally like groupings of bright red, orange, pink, purple or yellow flowers. While butterfly bushes do attract butterflies, they are considered invasive and so should be used only sparingly. Host plants for the caterpillars are much more specific to the particular butterfly. Swallowtails, both black and yellow, for instance, only like curly leaf parsley, mint, or dill.
For more details about local butterfly species and suggestions for specific plants, check out the Penn State Extension’s website, “Gardening for Butterflies.” http://extension.psu.edu/natural-resources/wildlife/landscaping-for-wildlife/pa-wildlife-8
The Community Garden Club at Wayne has now undertaken a new project — that of maintaining the Bird and Butterfly garden on the Radnor Trail opposite the Wayne Art Center dedicated to Elizabeth Chew Bennet, a life-long Radnor resident.
Butterflies are fascinating insects, and following their life cycle is intriguing. Creating and maintaing a garden for them is not only beautiful but also good for the environment. Butterflies play an important role in pollinating flowers, but due to insecticides, loss of habitat, and the introduction of more exotic plants, their numbers are decreasing. For instance, there are fewer monarch butterflies east of the Mississippi, in part due to fewer and fewer milkweed plants. With more housing, shopping centers, and other encroaching civilization, wild areas with abundant milkweed disappear. Monarchs only lay their eggs on milkweed since that is the only food their caterpillars eat. In fact, all caterpillars are very particular about what they eat and have very limited diets. A butterfly garden must, therefore, not only have flowers full of nectar for the adults, but host plants for their offspring.
Some of the requirements for a good butterfly garden include lots of sun, as well as sheltered areas to protect the insects from wind, cluster plantings of both nectar flowers and host plants, perhaps some rocks for the butterflies to rest on and enjoy the sunshine, wet patches or puddles, and of course, minimal or no use of pesticides.
Nectar plants are quite numerous. Butterflies generally like groupings of bright red, orange, pink, purple or yellow flowers. While butterfly bushes do attract butterflies, they are considered invasive and so should be used only sparingly. Host plants for the caterpillars are much more specific to the particular butterfly. Swallowtails, both black and yellow, for instance, only like curly leaf parsley, mint, or dill.
For more details about local butterfly species and suggestions for specific plants, check out the Penn State Extension’s website, “Gardening for Butterflies.” http://extension.psu.edu/natural-resources/wildlife/landscaping-for-wildlife/pa-wildlife-8