Image by Tim Kennelty

Episode 30: Flowering Annuals, Perennials, and Invasive Multifora Rose

Episode 30: Flowering Annuals, Perennials, and Invasive Multiflora Rose

This episode is filled with all types of flowering plants including annuals (marigolds, zinnias and cosmos), Perennials (cranesbill geranium, wisteria, milkweed) and Invasives (multiflora rose).There is something of interest for all types of gardeners and gardens. Listen and learn!

Hosts: Tim Kennelty and Jean Thomas

Photo by: Tim Kennelty

Production Support: Linda Aydlett and Teresa Golden


Flower Power (with Linda Levitt): | Marigold; Michigan State University | Growing zinnias in your flower garden;

Texas A&M | Cosmos Produces Cosmic Beauty

The Cover Up (with Jean Thomas and Tim Kennelty): Wild Geranium, Geranium maculatum – Wisconsin Horticulture ; Taylor's Guide to Ground Covers, Vines & Grasses (Taylor's Guide to Gardening): By The Editors: 9780395430941: Books ; Groundcovers (Burpee American Gardening Series): Roach, Margaret: 9780671846473: Books

Good Plant/Bad Plant (with Tim Kennelty): Asclepias syriaca | UMass Amherst Landscape, Nursery & Urban Forestry ProgramPenn State Extension | Monarchs and Milkweed ; NC State Extension | Asclepias incarnata; NYIS | Multiflora Rose; University of Connecticut | Multiflora Rose (Rosa multiflora); Penn State Extension | Multiflora Rose


Welcome to Nature Calls: Conversations from the Hudson Valley. Our team's goal is to present science based information about gardening and all things nature in New York's Hudson Valley. Hosts Jean and Tim, along with team members, Teresa: and Linda, are Master Gardener Volunteers for New York's Columbia and Greene counties. So if you're interested in gardening or nature or nuggets of information about what's happening outside your door, settle in, enjoy the conversation. Whatever the season, we have something to say.

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Tim: Hi, I'm Tim Kennelty.

Jean: And I'm Jean Thomas.

Tim: And welcome to another episode of Nature Calls: Conversations from the Hudson Valley. Linda Levitt is here with another episode of Flower Power and she's going to talk about some of our favorite annuals, right?

Jean: Yep, the ones everybody knows and loves and with good reasons, the zinnias and marigolds and cosmos.

Tim: You know, I've been mocked for liking zinnias but I think zinnias are one of the best flowers. They're so tough and beautiful. And there's lots of colors and so I can't wait to hear Linda talk about that.

Jean: It's great. She covers a whole bunch of stuff.

Tim: Excellent.

Jean: We're back with another episode of The Cover Up.

Tim: The Cover Up, right. That a spy novel. No, no, no, it's not a spy. We're talking about ground covers and vines. Right. What are you talking about this time?

Jean: I'm talking about geraniums. What are you talking about?

Tim: Geraniums, like geraniums like in a window box geraniums?

Jean: Not really.

Tim: No? No? Like the perennial geraniums. The hardy geraniums. The cranesbill geraniums?

Jean: Yeah.

Tim: They're real collector items, because there's lots of them out there.

Jean: They can be, and they crossbreed and hybridize them like crazy.

Tim: I wouldn't use this another one I wouldn't necessarily think of as a ground cover, but they do make great ground covers.

Jean: They're awesome.

Tim: Yeah, yeah. And I am talking about not the invasive wisteria. I'm talking about American wisteria, frutescens. You ever grown that?

Jean: No, I had a Chinese one that I'm still battling that took off and tried to eat my forest.

Tim: They live forever. Yeah, you can cut them down. That's not what we're talking about. We're talking about the American ones. They're much better behaved. They're really fragrant and beautiful, beautiful blossoms. So it's a great well behaved climbing vines. And what else is on today's episode, Jean? My Good Plant/Bad Plant. I'm talking about some good and bad plants, favorites of yours. I know. Right? True. That's yeah, yeah. Milkweeds, the milkweeds which are really, really important in terms of being pollinator plants and being larval plants for monarchs.

Jean: And they smell good.

Tim: Yeah. And your favorite plant: the ouch plant. Right?

Jean: Yep. I call them the mean rose.

Tim: The mean roses.

Jean: They smell good too.

Tim: Multiflora roses, which are horrible invasives and really can be kind of harmful to you if you're out there in the field, they can really snag you and we're going to talk all about how you can manage those plants. So whether you hate it or love it, you're going to want to listen in to hear that.

Jean: Absolutely.

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Linda: Welcome to Flower Power a regular feature of this podcast that will focus on all things flowers. I am Linda Levitt, a Master Gardener Volunteer with the Cornell Cooperative Extension of Columbia and Greene counties in New York's Hudson Valley. Approximately once a month we will cover different types of flowers how to best select, plant and care for each of the flowers discussed. Today I'd like to talk about three easy to grow vibrant colored annuals that will enhance your garden from late spring to early summer until the first fall frost. We're going to talk about marigolds zinnias and cosmos. These three annuals have a great deal in common yet do vary in their look and composition. I would first like to talk about each of these plant varieties on their own.

Linda: Let's start with marigolds. Marigolds are a favorite, no fuss annual they bring bright sunshine colors to your gardens and containers. The flowers germinate quickly from seed and will bloom in about eight weeks. This plant is an exceptionally easy to grow project for kids or garden newbies. They are a great companion in all vegetable gardens to help protect your vegetables from predators. They tend not to be a favorite of deer or rabbits, although there's never a guarantee. Marigolds are susceptible to gray mold, bacterial leaf spot powdery mildew and root rot. Marigolds are beneficial repelling several types of insects. According to the New York Botanical Garden, they actually help keep away mosquitoes, aphids, whiteflies, and many more. There are approximately 50 species of marigolds in shades of orange and yellow, with highlights of red gold, copper and brass ranging in size from six inches to four feet tall. The three most common are the French marigold, the African marigold and Signet marigold. Now, you might hear the term calendula marigold, which is also called pot marigold. But really it is not related to the common miracle that you know of, but it's actually an herb grown for its culinary and medicinal uses. Marigolds are an excellent choice for live bouquets, growing in containers or planting as a border along sidewalks and driveways due to their high heat tolerance.

Linda: The next one I'd like to talk about zinnias. Zinnias are one of the easiest annuals to grow, offering an explosion of color and shades of orange, pink, purple, red, white, and yellow. Some varieties even are bicolored. They grow quickly and reliably, making them a great choice for first time flower grower. They come in a variety of shapes and sizes. The dwarf varieties grow six to 12 inches, while others grow up to four feet tall. These flowers are susceptible to fungal spot, powdery mildew and bacterial wilt. Keeping the foliage dry and providing good air circulation can actually help to prevent these diseases. They can also host caterpillars, mealy bugs and spider mites. There is a series of zinnias called Profusion series, which now have shown to have increased resistance to powdery mildew. Zinnias may be deer resistant and may even help protect other plants located next to them. Zinnias come in a variety of shapes and sizes with stars, daisies, dahlias, buttons, and domes. It is suggested that you incorporate different varieties and a mixed border for a mixture of height and color. Using smaller dwarf varieties and window boxes along edging and containers. Long strong stems make these proficient for cut flower arrangements.

Linda: The third one is the cosmos. The common name is the Mexican Aster. Cosmos are freely flowering, quintessential cottage garden like plants that are easy to grow from seed, maturing in about two months. They may be considered slow to germinate but it will bloom quickly after that. The flowers sit atop a long slender stem that comes in a variety of colors and look very much like daisies. They are considered invasive in southern United States however, so you may want to consider planting them in containers. There are over 25 species of cosmos. Cosmos sulphureus is native to Mexico, Central America and northern South America, yellow in color and drought tolerant. Cosmos bipinnatus is our colorful Daisy like flowers in white, pinks, reds and orange. They may not be heat resistant, tolerant as the other varieties but grow well in any sunny border. Then you have the Chocolate cosmos. They are a separate species. These dark red flowers smell like chocolate and it is a perennial plant hardy to zone seven. It requires higher maintenance and grows from tubers rather than seeds. Since cosmos is a member of the Aster family, they are susceptible to disease called Aster yellows. The leaves will appear yellow and the flowers distorted or stunted these plants should be destroyed.

Linda: Now let's talk about the characteristics of all three of these annual plants. The climate zones well since they are annuals there really are no climate zones, there is seasonal use in all zones.For light, all three of these require full sun exposure. Now for soil there is somewhat of a difference marigolds and Zinnias like fertile well draining soil, whereas the cosmos do not perform well in rich soil. The plants will become tall and leggy and will not perform well. All three will bloom during the summer until frost and zinnias will tend to be less prolific in the heat of the summer. All three plants attract various pollinators. The marigold plants will attract butterflies, bees, ladybugs and other beneficial insects. Zinnias will attract butterflies and hummingbirds. Whereas cosmos will attract bees, butterflies and birds. So all three of these annuals can be sowed from seed and after the danger of frost has gone. The water requirements for all three of these plants are different. Marigolds, for example, it is best to water these plants at the base of the plant because overhead watering tends to rot the flowerheads do water regularly in high heat or dry weather, and if planted in containers they should be watered daily zinnias you may want to water regularly about one inch per week these two should be watered from the base of the plant they can tolerate dry conditions but will do much better with moisture. Finally, cosmos once established you do not need to water these plants unless there is a prolonged drought they can tolerate drought better than the other two. As you can see, these are three easy to grow colorful additions that can be added to your garden each year. I hope you have enjoyed this episode of Flower Power. Thank you for listening. You will find additional information for this episode on our website. Until the next time. I am Linda Levitt. And please remember to stop and smell the flowers

You're listening to Nature Calls: Conversations from the Hudson Valley.

Stay tuned for The Cover Up.

Jean: Hi, I'm Jean Thomas.

Tim: And I'm Tim Kennelty.

Jean: Welcome to The Cover Up.

Jean: Ah, The Cover Up. Today we're talking about vines and ground covers, as usual. Tim's picked wisteria

Tim: Jean, hit me with your best shot, what wonderful ground cover are you talking about?

Jean: I decided I wanted to indulge in a ground cover capable of the same powerful statement as mysterious. And that's geraniums.

Tim: And we have a theme today right? Because since I'm talking about native wisteria, you're talking about native geraniums. There are some that are the same color right? That's the theme.

Jean: You can mix and match in the purple and white range. So it could be kind of massive, not the Pelargoniums though the annual garden geraniums like you see in window boxes, but Cranesbill geraniums. The Latin species name is geranium derived from the resemblance of the seed head to a Crane's bill. For those of you who can't help but ask then why are Pelargoniums also called geraniums? This is a total digression, Tim will probably kill me, but here it is. They're cousins from the same family. The name Pelargonium even refers to the similarity of the seed head to, get ready for this, a stork. You can't make this stuff up. And don't get me started on scented geraniums. They're annuals too and not groundcovers. I'll have to see if Linda Levitt will give us a Flower Power talk about them one day. These ground covered cranes bills are hardy perennials with a wonderful attitude. There are about 300 species and I don't even know how many hybrids there are. The flowers are available in many shades of blue, pink and white, and the leaves provide a spectrum of shape and color that keeps the plant interesting when it's not in flower. Some gardeners make collections of these and plant them in patterns that look like tapestries. Garden centers present them as perennials in their sales yard, and we often think of them as specimen plants. But once you open your imagination to using them as groundcovers, they can be glorious. The most common local wild Geranium is Geranium maculatum and it's found in clumps on the forest edge. Their growth habit is similar to the commercial types but a little more open in form. They'll make colonies in their a terrific native pollinator. The other species that include most of what we can buy include the macrorrhizum, aka Bigroot and dressy, or Pyrenean which doesn't like heat and the Sanguineum named for the hot magenta flowers. Although it comes in whitetoo, go figure. They all form mats of foliage and spread happily forming colonies. They love mixed flower beds or just lounging around along walkways and lawn edges. They especially like to be underplanted with the small spring flowering bulbs. You can find geraniums as dainty or as coarse an habit as you like. Most are hardy to zone for and once established, they'll putter along happily for years with minimal care. My favorite feature of these geraniums is their eagerness to please. I have often rated beds of them, especially the big root type, plopped whole pieces into new homes and had both beds all grown back full and fluffy. By the fall. I've divided and shared all the different geraniums that I grow and never had one refuse to flourish. They also grow in tidy patterns. Most types except the daintiest makes beds that look like they were drawn with a ruler. Their edges are so neat. They're especially pretty under shrubs. They look like precise little carpets, the daintier ones sometimes need a little coddling and mixed beds until they're well enough established to stand up to the bully If you're a beginner and want a nice cooperative show off Johnsons Blue and Roseanne are a couple of the best known, but new hybrids of both are popping up all the time. Oh, I almost forgot. Many of them smell good too. Usually it's a crisp herbal scent sent out from the foliage. The other thing I almost forgot is the warning. It's very possible that you will become infatuated with these cheerful little workhorses and become the dreaded collector. I personally have exercised restraint and only have five varieties, so far.

Tim: That's unlike you gene to exercise any restraint with anything. And as you know, sometimes we disagree about these things. But I have to admit, I too, am a fan of the geraniums I can't believe it. We agree. I have many of the species and cultivars in my garden too. And I love how hardy and tough they are. Just like the wine I'm talking about today, our native Wisteria, Wisteria frutescens. And please before I go any further, let me be clear that I'm not talking about Wisteria sinensis, the non native Wisteria that you're probably thinking of. That vine was introduced to the United States in 1916 as an ornamental, and was widely planted and cultivated throughout the country. And it's still popular in the nursery trade. In spite of its weedy and somewhat destructive habit. I planted a couple of vines near my deck many years ago, and I'm still battling them, they're really difficult to eradicate. As they mature, they get so heavy, they can pull down structures like me on the deck. This vine has been reported to be invasive in 19 states, from Massachusetts to Illinois to Texas. So Jean, I bet you didn't think you were gonna get a lecture on invasive species. But sometimes the great plant is the native version of something nonnative that's not great. So this is another case where it pays to know just not just the common name, but also the Latin name of the plants. And today, the good vine is again, Wisteria frutescens, commonly referred to as American Wisteria. This is a beautiful vine that can grow anywhere from 15 to 40 feet. It has shiny green leaves and beautiful six to nine inch clusters of drooping lilac or bluish purple flowers that appeared in May to June after the plant has leafed out. One of the things that I really liked about this vine is that the flowers can be quite fragrant, so mine is planted near my sidewalk where I can smell it. If you're lucky, you may even get a second flush of bloom in late summer. Even though it's not nearly as aggressive or weedy as its nonnative cousin frutescens does need a sturdy structure like a strong trellis, railing or fence to support it. It can be pruned in the fall as flowers appear on new wood. After flowering, a long bean-like seed pod appears, but don't worry. Unlike sinensis, American Wisteria seed is much more difficult to germinate, so you're most likely not going to have new vines popping up all over your yard. This vine likes loamy moist soil that can take some drought. To get the most flowers, plant it in a really sunny location. American Wisteria is also deer resistant, and it tends to attract both butterflies and hummingbirds. In fact, it's the host plant for a number of different Skipper species. This vine has a couple of nice cultivars like Amethyst Falls, which is said to be more floriferous and of flowers at a very young age, and Nivia which has white flowers. So if you're drawn to the beautiful purple flowers have Wisteria, but don't want that monster that can pull down your deck, check out Wisteria frutescens.

Jean: That's it for this edition of The Cover Up. Until next time.

You're listening to Nature Calls: Conversations from the Hudson Valley.

Stay tuned for Good Plant/Bad Plant.

Tim:Welcome Good Plant/Bad Plant where we focus on two plants per episode one that's ecologically valuable and one that's at the other end of the spectrum that's invasive or noxious weed, thus good plant, bad plant. I'm your host Tim Kennelty.

Tim: In this episode, we're going to talk about a good plant and a bad plant that both smell really nice. However, one of them is a butterfly magnet, and the other can actually physically harm you. I think I know which one I'd want in my garden. So the good plant you may have guessed is actually a group of plants, the milkweeds and the bad plan is none other than the thorny multiflora rose. So we'll start with one of my feet favorite groups of plants, the milkweeds. Let's first talk about the common and Latin names of this plant. The Latin name for milkweeds genus as Aesclypeus, is derived from Aesclypeous, the Greek god of medicine, because some of the milkweed species have a history of medical use for wart removal, and lung disease. And note that weed is part of the common name. Many native plants such as iron weed, sneezeweed, and butterfly weed were thought of as weeds because they were abundant and rapidly spread in disturbed areas, even though they have significant ornamental and wildlife value. So don't judge a plant by only its common name. Milkweeds have gained recognition in recent years, and rightly so because they're the only host plant for monarch butterflies. Yes, you heard it right, the only plant that monarchs will lay their eggs on and the only leaves that Monarch caterpillars will eat to survive are milkweed leaves. And since monarchs numbers are declining in an alarming rate, milkweed should be at the top of your list for inclusion in the garden. And if that's not enough, milkweed flowers are rich and pollen and nectar and are extremely attractive to native bees, wasps and beetles, as well as a large number of butterfly species in addition to monarchs. In fact, more than 400 different species of insects are known to feed on some portion of this plant. The good news is that there are more than 70 different species of milkweeds in North America. And no matter your cultural conditions, there's most likely and milkweed for you. The most common milkweed is well Common Milkweed or Asclepias syriaca. This is a tough plant that likes full sun that can tolerate a variety of different soils. It's got a deep taproot. So once it's established, it's really not going anywhere. I happen to love this plant for its bold looks and beautiful scent, and I really let it grow wherever it wants to, but I certainly understand that some people think it's a bit too aggressive. If you have a wet area like around a pond, you might want to try swamp milkweed. Also an unfortunate common name for a beautiful well behaved plant with deep pink flowers. And if you have drier, well-drained soil in hot sun, check out butterfly weed with all the same benefits as common milkweed, but in a smaller, less aggressive plant with bright orange flowers. So if you're serious about helping the monarchs and want an easy care, beautiful plant, make sure you include milkweeds in your garden.

Tim: Now for a bad actor, the dreaded multiflora rose, I guess not really dreaded so much since it was actively planted for a century in the US. This invasive perennial shrub from Asia was first introduced in this country in the 1860s as rootstock for ornamental rose breeding programs. By the 1930s the USDA was actively promoting the multiflora rose to be planted in large numbers in the Northeast and Midwest for erosion control, wildlife enhancement and to deter roaming animals. Even as recently as the 1960s. Some states Conservation Departments were encouraging its planting for wildlife along highways and to reduce headlight glare. Well, now we know in retrospect, really what were they thinking? Multiflora rose has become one of the most pernicious invasive plants quickly forming impenetrable thickets, pushing out native plants and shrubs and inhibiting nesting birds. This is a really tough sell in early summer produces multiple fragrant white or pink blossoms. Great, but that's the end of the good news. A single plant can produce up to 500,000 seeds per year dispersed by birds and other fruit eating animals. The seeds can be viable in the soil for up to 10 years. It's a monoecious plant producing both male and female flowers. So a single plant can quickly turn into a colony and there really no effective herbivores eating this plant. Really can you blame them? It's covered in sharp thorns the curve towards the base of the cane, so you can easily be impaled by just passing by. So what can you do if you find a multiflora rose on your property? Regular pulling, digging, mowing and cutting this piece can keep it at bay, but this is like most invasive controls a multi year project. Some folks are even using goats and sheep to manage this plant on their properties. chemical controls are also an option and I'll include some links with more information on that. There are no commercially available biological controls. Although rosette disease which causes witch's broom can kill infected plants. The best defense is always early detection and removal. So get out there and not only smell the roses, but make sure you don't have this invader in your yard. That's it for another edition of good plant bad plan. And remember, as a gardener you can make a difference. If you want to support wildlife in your yard plant natives.

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That concludes another episode of Nature Calls: Conversations from the Hudson Valley. We'd like to thank Sandra Linnell and Devin Connolly from Cornell Cooperative Extension of Columbia and Greene counties for production support. And a special thank you to our listeners for joining us on this episode of Nature Calls: Conversations from the Hudson Valley. You can find links to any of the topics mentioned in this episode at our website at Comments and suggestions for future topics may be directed to us at or on the CCE Master Gardener Volunteers of Columbia and Greene County's Facebook page. For more information about Cornell Cooperative Extension of Columbia and Greene counties, visit our website at CCE Columbia or visit us in Hudson or in Acra. Cornell Cooperative Extension provides equal programming and employment opportunities.

Last updated August 18, 2022