Survival of Baby Chickadees Declines in Yards with Less Than 70% Native Plants

Want to support nesting songbirds? Shoot for a minimum of 70% native plant cover in your landscaping, and 94% would be better, according to a recently published study by the University of Delaware’s Desirée Narango and others. For their study, the scientists chose Carolina chickadees as a representative suburban songbird. Homeowners across the southeastern U.S. delight to see them in our yards and at our bird feeders. Like most songbirds, chickadees provision their nestlings with insects from the landscape around their nest.

Caption: Landscapes with more than 94% native plants were excellent habitat for plant-eating caterpillars. These habitats provided enough caterpillars that Carolina chickadee parents could feed their young. Landscapes with 70 to 94% native plants may or may not support enough caterpillars. Nestlings in landscapes with less than 70% native plants were food-limited and had low survival rates. Image of chickadee courtesy of the National Zoo.
Caption: Landscapes with more than 94% native plants were excellent habitat for plant-eating caterpillars. These habitats provided enough caterpillars that Carolina chickadee parents could feed their young. Landscapes with 70 to 94% native plants may or may not support enough caterpillars. Nestlings in landscapes with less than 70% native plants were food-limited and had low survival rates. Image of chickadee courtesy of the National Zoo.

Study results show that baby chickadees reared in landscapes with less native vegetation are food-limited and much less likely to survive. So much so that the authors termed landscapes with less than 70% native vegetation as “food deserts” and “habitat sinks”. A habitat sink is a place with habitat sufficient to attract animals but insufficient to support their survival or the survival of their young. Habitat sinks are bad for a species because breeding pairs do not produce enough young birds to replace their parent’s generation. It would actually be better for the chickadees not to have that habitat available at all. Continue reading

Black-eyed Susans Attract Pollinators and Other Beneficial Insects

Black-eyed Susans are easy to grow and will attract many pollinators to your garden. The dark center or eye of the flower head holds 250 to 500 individual flowers, and to pollinators, each one of these is a shallow nectar cup. These are shallow enough that even small wasps and flies can drink from them, and many small wasps and flies are predators or parasitoids of pest insects. These tiny, dark flowers bloom from the outer rim of the eye and progress inwards with time. It’s a buffet that attracts a wide variety of small to medium-sized pollinators, including many species of insects beneficial for pest control. This blog provides a few examples of the wonderful insects you can attract to the home garden by planting Black-eyed Susans.

Black-eyed susan

A Black-eyed Susan isn’t a single flower, it’s actually hundreds. Notice the individual corollas of the “eye”, and the yellow pollen along the outer ring which indicates those flowers are in bloom. Watch a pollinator visit, and you’ll notice that they rotate around, drinking nectar from each one of the tiny blooms in this ring. The Metallic Green Bee, shown here, is a good example of the small bees that enjoy Black-eyed Susan’s big, soft, landing pad and shallow flowers. Notice the pollen packed onto the bee’s hind legs. Continue reading

Plants for Monarchs: Milkweeds and More

asterQ: I planted seeds of what I thought was a milkweed (Asclepias). The plants look somewhat like milkweed, but they are close to 4 feet tall with no sign of flower buds to confirm their identity. There are leaf buds at the axils, which I don’t see on other milkweeds. What is this plant? I would like to have milkweed plants for Monarch butterflies.

A: What you have here is not a milkweed. It is Tall White Aster, Symphyotrichum lanceolatum, and the good news is, it is actually what the Monarchs need more at certain times of the year than Asclepias. More on that in a minute, but first, a few notes and a caution about planting milkweeds.

As many people know, milkweeds are essential host plants for Monarch butterfly caterpillars. We commend people for adding milkweeds in their gardens to support butterfly conservation!

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Bottlebrush Grass – Gorgeous Native Ornamental For Your Garden

A wild Bottlebrush Grass plant in the Potomac River floodplain
A wild Bottlebrush Grass plant in the Potomac River floodplain

Elymus hystrix got its common name, Bottlebrush Grass, by having seed heads in the shape of a bottle-washing brush. Both the seed heads and the stems are coated with a white wax, making this a gorgeous ornamental grass for your garden, especially when situated against a dark background.

The Nature of Bottlebrush Grass

In the winter, the basal foliage is lively and green, even during the coldest of winters. As a cool-season grass, Bottlebrush does most of its growth in spring. Flower stems are sent up in June and seeds are set in July.

Bottlebrush is native throughout Maryland, but only in soils with good calcium availability. That makes it uncommon in the Coastal Plain, where soils tend to be nutrient poor. Even there, it does grow wild where shell deposits have enriched the soil.

Many insect species use the Bottlebrush Grass as a host plant, including the Northern Pearly Eye Butterfly. Photo by MDF, via Wikimedia.
Many insect species use the Bottlebrush Grass as a host plant, including the Northern Pearly Eye Butterfly. By Mdf GFDL or CC-BY-SA-3.0 from Wikimedia Commons

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The Cure for All Your Ills Might Just Be A Native Plant

You may know Yarrow as a great garden plant for attracting small pollinators and beneficial insects. But there’s a lot more to it than that!

Yarrow, Achillea millefolium, has been used as a medicinal for a very long time. No, we’re not talking about your great-grandmother, we’re talking about Neanderthals. Archeologists have identified yarrow among the medicinal herbs that were buried with a Neanderthal 65,000 years ago. From Asia to North America, cultures of our own species have used yarrow medicinally for longer than records have been kept. In Greek mythology, the warrior Achilles was schooled on the medicinal uses of yarrow, for whom the genus has since been named. In recent decades, ethnobotanists noted that numerous indigenous cultures around the globe were using yarrow to treat the same types of ailments, an indication that an herb is in fact probably medically active for those conditions (see table). In this millennium, these suspicions have been borne out by recent clinical trials showing: more rapid healing of flesh wounds; decreased menstrual pain; improved kidney function; improved liver function; and improvement of dry mouth in chemotherapy patients. Gee, those Neanderthals were on to something!

But is Yarrow a native plant? Again, research conducted in the new millennium has shown that what we once called Achillea millefolium is actually a cosmopolitan complex of species and subspecies. Among those, American Yarrow (Achillea borealis), arrived in North America via the Alaskan land bridge during a period of low sea level, probably within the last one million years. Since that time, it has spread across the continent, using a powerful bag of evolutionary tricks to adapt to diverse environments such as dunes, mountain tops, and mesic meadows. Populations from these different environments are genetically distinctive, and there are likely to be multiple ecotypes even within a local area. According to Weakley (2015) if you encounter Yarrow in a native meadow in the Mid-Atlantic, it is most likely the native American Yarrow. However, the similar-looking aliens A. millefolium and A. filipendulina are sometimes found in disturbed areas, especially near port cities like Washington, D.C. and Baltimore.

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How Invasive is Chinese Silvergrass?

Chinese silvergrass, Miscanthus sinensis, is a beautiful ornamental grass. In its native range, it inhabits disturbed areas and meadows. Here in North America, it escapes cultivation to occupy similar types of places, and, given enough time it can displace native meadow vegetation. If you have not yet had the opportunity to see how invasive this species can be, then this is your chance.

I was driving home from a meeting in Baltimore County when I started to notice occasional Miscanthus plants growing in unkempt areas along the roadside. This went on for a mile or two, and then suddenly I arrived at what quite clearly was the epicenter. The lighting was perfect, so I pulled over, grabbed my little video camera and went for a walk around the area to see how extensive the infestation might be. The footage posted here is unedited so you will see exactly what I saw on that walk.

I mentioned the Miscanthus to a friend who used to walk past this substation to get to school, and he told me Miscanthus was planted at the substation in the mid-1980s, and that it has spread a little each year ever since. Now it occupies several private properties, and as per his description “miles” of the local power lines.

According to the U.S. Forest Service, Miscanthus spreads by both seeds and rhizomes. It is very difficult to eradicate once established because even small bits of rhizome will start new plants. They also warn that it is highly flammable, and at this time of year it should be considered a fire hazard.

What about you? Do you see Miscanthus escaping in your area? Leave us a comment!

Learn more about invasive plants in Maryland.

By Sara Tangren, Ph. D
Agent Associate | Master Gardener Trainer | Sustainable Horticulture and Native Plants