Category Archives: flowers

Mandevilla: Tropical Beauties Worth Keeping

mandevillaMandevilla plants are popular summer bloomers here in this area.  I have always admired these vigorous climbers with bright, large, trumpet-shaped flowers. Usually, I see pink, red, or white blossoms, but there are other colors on the market.

Mandevilla is a member of the Apocynaceae family, also known as the dogbane family, cousin to Plumeria (frangipani), Nerium (oleander), Vinca (periwinkle), Amsonia (blue star), and Hoya (wax plant). Native to southeastern United States, Mexico, Central America, South America, and the West Indies, these are considered tropical plants here in the DC area. Mandevilla was named after Henry Mandeville, a British diplomat and gardener who discovered this plant in Argentina and sent it back to England in the 1800s.

tango twirl mandevilla

Tango Twirl has fully double petals, photo courtesy of Doreen Wynja for Monrovia

In recent years, there has been a tremendous amount of hybridizing with mandevillas. There are many lines or series such as Sun Parasol, Sunvilla, Bombshell, and Parfait. There are plants that are more compact than the species, really compact for containers, and plants with variegated foliage, double-petaled flowers, and new flower colors such as apricot. They are all beautiful, but they are not cheap. Although they may cost a little more, they thrive in our hot, humid summers; are deer and rabbit resistant; and attract butterflies and hummingbirds.

They do need support and should be planted with a trellis or obelisk or planted near a pergola or a fence. If they are grown in containers, they will need fertilizer in the summer for continuous blooms.  They are actually very versatile. I have seen them in containers at gas stations where they thrive despite the heat and neglect and I have seen them used to decorate arbors, arbors and pergolas.

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Brookside Gardens in Wheaton, Maryland

Because these are tropical vines, hardy to Zone 10, they will die here in the DC area in the winter. But you can protect them over the winter so they can be brought outside again next year for another season of beauty.

apricot colored flower

Apricot is an unusual, apricot colored flower, photo courtesy of Doreen Wynja for Monrovia

There are basically two ways to do this. One is to grow them like houseplants indoors and the other is to let them go dormant for the winter. In the fall, before the temperatures dip below fifty degrees, bring the plant inside. Remember that night temperatures can dip below fifty even though day temperatures are still warm in the fall.

To grow like a houseplant, trim them back first. It can be a real haircut, up to one half of the foliage, but do it so you are removing leaves and stems for reducing transpiration, not to make it ugly. Then place in a room that has much light as possible while as cool as possible. Water less frequently; do not fertilize. It may not bloom but that is okay, it is just surviving for a few months. Keep watching for pests. In the spring, prune and fertilize. In early June bring the plant outside. Place in shade first and gradually move to full sun.

The dormant method is to bring the plant indoors and trim back to about twelve inches. Put in a cool garage or basement where temperature is above freezing. Make sure it does not dry out completely. Water only to prevent it from drying out. In the spring, bring it in the house to increased light and heat. In early June, bring it outside. Again, shade first and gradually to full sun.

This way, your mandevilla plant should provide color every summer and you will certainly get your money’s worth.



Growing Zinnias That Are Resistant to Powdery Mildew

Mexican zinnia

I grow zinnias every year in my Virginia garden. Zinnias are probably one of the easiest flowers to grow from seed in this area. These warm season annuals can be sown directly into a container or on the ground after the last frost. They need full sun, good air circulation, and they are not particular about the soil. The flowers attract butterflies and bees; deer do not bother the plants.

The only hitch is that some species are prone to powdery mildew. Our hot and humid summer is an ideal environment for this fungal disease that creates a white coating on the plants. It does not kill the plants but makes the foliage unsightly. However, there are some zinnias that are resistant to powdery mildew.

Narrow-leaf zinnia, Zinnia angustifolia or Z. linearis, is a foot tall, bushy plant with narrow leaves and small, single, daisy-like flowers. The flowers are about an inch wide with single-colored petals such as orange, red, pink, white, or yellow. Because of its compact size, it makes an excellent window box or container plant and can be used in the garden as a border plant. These are small but you cut a bunch and put in a small vase.

Zinnia angustifolia

Mexican zinnia (Z. haageana) is like narrow-leaf zinnia in shape, size, and foliage. The flowers are a little larger and can be single, semi-double, or double petals. Each flower has more than one color – usually a spectrum of sunset colors: red, orange, burgundy, yellow, and cream. I discovered them when I purchased Renee’s Garden Persian Carpet mix, which I love. There are other flower blends such as Aztec Sunset, Jazzy Mix, Old Mexico, and Soleado. Again, small flowers but a bunch can be cut for small vases. These are excellent for containers and as border plants.

There are two series of zinnias that have been bred specifically for powdery mildew resistance:  Z. marylandica, also called Zahara, and the Profusion series. Zahara has flowers that are larger than the two previously mentioned species, about 2 to 2 1/2 inches wide. There is a wider flower color range too. The plants are taller, about 18 inches high, which is better for floral arrangements. Profusion is pretty much the same as Zahara, a taller zinnia with larger flowers. Zahara and Profusion give you a wide range of colors to pick from, these are easy to find in seed catalogs.

All of these are going to be easier to find if you look for the seed instead of a plant in a garden center. The companies below have these varieties and here is a list of more than 100 seed companies if you want to look for more zinnias.
Burpee
Johnny’s Selected Seeds
Kitchen Garden Seeds
Park Seed
Renee’s Garden

Mexican zinnias in a vase

 

Purple Blooming Anise Hyssop

anise hyssop at the National Herb Garden in July

Anise hyssop (Agastache foeniculum) is blooming now in the summer. A native, herbaceous perennial hardy to zone 4, this plant is short-lived but self-seeds and spreads a bit by rhizomes. In March, the leaves emerge with a purple hue. As the plant grows the leaves become green although there is a golden cultivar. A member of the mint family (Lamiaceae), the leaves have scalloped edges and look like catnip leaves. Anise hyssop grows a few feet tall and about one foot wide. In the summer, there are small purple-blue flowers on 4 to 6-inch terminal spikes, creating fuzzy wands. The flowers attract beneficial pollinators, including butterflies and hummingbirds. Because the foliage is so fragrant, deer are not interested.

Anise hyssop is a full sun to part shade plant tolerating a wide range of soils in a well-drained site. The purple-blue flowers provide contrast to orange and yellow flowers and complement purple foliage plants.

purple foliage of anise hyssop in March

Anise hyssop can also be used as a culinary or tea herb. It is harvested for its leaves as well as its flowers. Although the aroma is categorized as anise or licorice, some might say anise with a touch of basil or anise with a touch of tarragon. The most common use of the leaves is tea but you can also add the leaves to lamb or pork dishes, to milk for making ice cream, sugar syrups, and/or sugar syrups for cough drops, cocktails, honey, butter cookies, and sugar to make flavored sugar. The leaves dry well, retaining their taste and fragrance.

Flowers are edible and can be used as a garnish for desserts, added to a salad, or added to a beverage such as ice tea. The flowers also dry well, retaining their color and aroma.

You can find small plants in the nursery in the spring or you can grow anise hyssop from seed. Sow the seed indoors under lights in order to transplant outside after the last frost or sow directly outside in the summer. Anise hyssop can be propagated by root division.

Anise hyssop is a great garden plant — it provides color in the summer, supports pollinators, and can be used for making tea or to add flavor and color to meals.

Carolina Allspice: Native, Deer-resistant, Summer-flowering Shrub

I have always admired Carolina allspice (Calycanthus floridus), a deciduous shrub that flowers in the summer.  This is such a beautiful plant I don’t know why other people don’t grow it more often. Native to the southeast region, Carolina allspice grows 5 to 8 feet tall, is deer resistant, and has no major pests and/or diseases.

The green leaves are relatively large for such a small bush. The mahogany red flowers bloom all summer long.  Pollinated by beetles, the 2-inch flowers look like a cross between a star magnolia (outer strap-shaped petals) and a lotus (curved inner petals with a central, raised button). In the fall, the leaves turn golden yellow.

These are understory shrubs meaning that they prefer to grow under the shade of tree canopy. Mine is under mulberry trees, or rather weeds, so it receives partial sun. They are well branched and respond well to pruning. They do not seem to be fussy about the soil other than wanting well drained soil.

Since 2016, my cultivar ‘Aphrodite’ has performed well and is in full bloom this month. The flowers are redder than the species and are supposed to smell like apples. I don’t detect this outside but if I were to cut them and bring them inside, the heat of the house seems to make them more fragrant.

The flowers can be cut for arrangements or for water bowls. When it was young, the flowers did not have a scent but I had read that young plants do not always have a fragrance. Apparently this attribute comes with maturity. The flower scent varies with plant so the other cultivars below may have a slightly different fragrance although they are all pleasant.

The leaves, bark and root are equally fragrant but more like camphor. If you crush the leaves or scratch the bark, there is a pleasant, almost lemony, camphor scent which reminds me of a friend who would put eucalyptus branches in her car for the heat to release the pleasant scent.

Mark Catesby, an English botanist who traveled the New World is credited with introducing the shrub during his colonial explorations. He said the bark was as “odoriferous as cinnamon” although I think the scent is more like a cross between lemon and camphor.  The dried flowers, leaves, and branches can be used for potpourris.

Carolina allspice is a great shrub for the Washington DC metro area. I recommend ‘Aphrodite’ but there are other cultivars on the market as well such as:
Athens: yellow chartreuse flowers
Burgundy Spice: burgundy colored flowers and leaves
Venus: white flowers and is more compact
Hartlage Wine: red blossoms with small yellow markings and larger at 12 feet.

Look for this at your local garden center and add one or two to your garden. You will be pleasantly surprised!

Flowering Bleeding Hearts Are a Sign of Spring

Bleeding hearts are beautiful spring blooming plants. They have green, fern-like leaves and nodding racemes of pendulous blossoms.

Each blossom looks like an earring or a puffy locket on a chain. The blossom is comprised of two outer rose-colored petals and the two inner white petals. If you turn the flower upside down and pull the rose petals apart you will see the lady in a bath. Lady-in-a-bath is another common name for this beautiful plant.

Bleeding heart is an herbaceous perennial that prefers moist soil, high in organic matter (think woodsy). Some shade is best, can be morning sun and afternoon shade or dappled light. With such delicate foliage, you would think that rabbits and deer would decimate bleeding hearts but neither seem interested in my Virginia garden.

These plants emerge in March and bloom in April and May. By June, the leaves have turned yellow and ratty and eventually the plant disappears. It becomes dormant in the summer. In order to prevent a gap in the garden, you can plant other herbaceous perennials such as hardy geraniums or hostas nearby or summer annuals in its place.

There are different cultivars on the market. ‘Alba’ has all white flowers against green foliage. ‘Gold Heart’ has yellow foliage that really brightens up a shady corner and ‘Valentine’ is striking with its cherry-red flowers and red-brown stems.

Try growing bleeding hearts. The plants are very easy to find at local garden centers but you can also dig and divide an established plant if you know someone who has one in their garden.

Virginia Bluebell Season Is Almost Here!

Virginia bluebell season is around the corner so plan now to see carpets of this ephemeral wildflower here in Virginia. Although mid-April has been the peak time in the past, it may come earlier since we had such a mild winter. Here are a few places in Northern Virginia to view colonies of bluebells; some places are already reporting blossoms now in March.

Bluebells (Mertensia virginica) are synonymous with early spring. Their blue trumpet-shaped flowers bloom above the green foliage in deciduous woodlands before the trees leaf out. These perennials emerge early in the year, bloom for a few weeks in March or April, and then die back to become dormant in the summer. The plants like the moist soil of the forest, high in organic matter. They self-seed and create colonies which is why you will see carpets of blue in the parks below. If you look closely, you will see that the buds are pink opening up to blue but the overall effect is a blue haze. These are native wildflowers, but you can purchase the plants from nurseries.

Balls Bluff Regional Battlefield Park (Northern Virginia Regional Park Authority), Balls Bluff Road, Leesburg.

Bull Run Regional Park (Northern Virginia Regional Park Authority), 7700 Bull Run Drive, Centerville. This park has a Bluebell Trail just off the Bull Run Occoquan Trail near the Atlantis Waterpark.

Great Falls Park (National Park Service), 9200 Old Dominion Drive, McLean.

Manassas National Battlefield Park (National Park Service), 6511 Sudley Road, Manassas. Best view is from the Stone Bridge.

Merrimac Farm (Virginia Department of Game and Inland Fisheries), 15014 Deepwood Lane, Nokesville.

Riverbend Park (Fairfax County Park Authority), 8700 Potomac Hills Street, Great Falls. Riverbend Park is celebrating bluebells on Saturday, April 8, 2023, from 10:00 am to 2:00 pm. There is a fee for attending this family event; however, the public can visit anytime to view the bluebells.

Scott’s Run Nature Preserve (Fairfax County Park Authority). 7400 Georgetown Park, McLean.

Turkey Run Park (National Park Service), George Washington Memorial Parkway, McLean.

Powdery Mildew Resistant Zinnias

Mexican zinnia

I grow zinnias every year in my Northern Virginia garden. Zinnias are probably one of the easiest flowers to grow from seed in this area. These warm season annuals can be sown directly into a container or on the ground after the last frost. They need full sun, good air circulation, and they are not particular about the soil. The flowers attract butterflies and bees; deer do not bother the plants.

The only hitch is that some species are prone to powdery mildew. Our hot and humid summer is an ideal environment for this fungal disease that creates a white coating on the plants. It does not kill the plants but makes the foliage unsightly. However, there are some zinnias that are resistant to powdery mildew.

Narrow-leaf zinnia, Zinnia angustifolia or Z. linearis, is a foot tall, bushy plant with narrow leaves and small, single, daisy-like flowers. The flowers are about an inch wide with single-colored petals such as orange, red, pink, white, or yellow. Because of its compact size, it makes an excellent window box or container plant and can be used in the garden as a border plant. These are small but you cut a bunch and put in a small vase.

Zinnia angustifolia

Mexican zinnia (Z. haageana) is like narrow-leaf zinnia in shape, size, and foliage. The flowers are a little larger and can be single, semi-double, or double petals. Each flower has more than one color – usually a spectrum of sunset colors: red, orange, burgundy, yellow, and cream. I discovered them when I purchased Renee’s Garden Persian Carpet mix, which I love. There are other flower blends such as Aztec Sunset, Jazzy Mix, Old Mexico, and Soleado. Again, small flowers but a bunch can be cut for small vases. These are excellent for containers and as border plants.

There are two series of zinnias that have been bred specifically for powdery mildew resistance:  Z. marylandica, also called Zahara, and the Profusion series. Zahara has flowers that are larger than the two previously mentioned species, about 2 to 2 1/2 inches wide. There is a wider flower color range too. The plants are taller, about 18 inches high, which is better for floral arrangements. Profusion is pretty much the same as Zahara, a taller zinnia with larger flowers. Zahara and Profusion give you a wide range of colors to pick from, these are easy to find in seed catalogs.

All of these are going to be easier to find if you look for the seed instead of a plant in a garden center. The companies below have these varieties and here is a list of more than 100 seed companies if you want to look for more zinnias.
Burpee
Johnny’s Selected Seeds
Kitchen Garden Seeds
Park Seed
Renee’s Garden

Mexican zinnias in a vase

 

Morning Glories: Easy-to-grow-from-seed Flowering Vines

Heavenly Blue

Morning Glories are so popular, they need little description. I plant them every year on a wooden banister. Their brightly colored faces greet me in the morning. By summer’s end, they have become close friends with the other plants, clasping their thin tendrils around branches of neighboring shrubs and perennials.

Growing morning glories from seed is easy if you bypass that hard seed coat. Either soak the seeds in water overnight before planting or nick the seed coat with a file to allow water to permeate. I start my seeds by soaking in water the night before. The next day, I sow them in small plastic containers with seed starting mix, under lights in my house. I do this in late April and transplant after last frost, typically Mother’s Day here in Northern Virginia. Morning glory seeds can be direct sown after Mother’s Day as well. They do need support so make sure they are planted in a place where the tendrils can clasp on to something.

Morning glories must be grown in full sun for the flowers to open up in the morning. Each flower only lasts one day but the vines produce many flowers. The vines prefer well-drained soil, not too rich or one gets more foliage than flowers. There is no need to deadhead or fertilizer.

Grandpa Ott’s

These annuals produce large seeds, many large seeds so it is easy to find them and save for next year. When the seeds develop in the fall, they are black with a papery brown coat. I cut the stem and drop the cluster of seedheads in a paper bag. Later, in the winter, I separate the seeds. One vine can produce many so this is a perfect plant to grow for seed exchanges.

For a while I have been growing Heavenly Blue from Southern Exposure Seed Exchange. Heavenly Blue is an heirloom with bright blue flowers and a white throat. This year I got Glacier Star from Renee’s Garden which is light blue with dark blue strips, creating a pinwheel effect. This is an heirloom so if I save the seeds, the resulting plants will look the same as the parents. If you want to save seeds, look for heirlooms or open pollinated, not hybrids.

Usually, morning glories have five fused petals in pink, white, magenta, or purple colors. For something different, check out Botanical Interests’ Chocolate which is salmon brown, or the Flying Saucer which is white with broad light blue streaks and a yellow throat. Or try Japanese morning glories from Baker Creek — the Kikyozaki mixed has pointed petals and the Imperial Japanese mix has a wide variety of markings on the blossoms. Kitchen Garden Seeds has a frilly pink called Split Second and a double purple one called Sunrise Serenade.

Try growing this easy annual vine this year. Morning glories are a great investment — one packet of seeds can reward you with flowers every year..

Mix of blue and pink

Early Spring Bloomers: Dwarf Irises

2014Marchgarden 017

Harmony

It is January and already I can see the green spikes emerging from the mass of dead, brown leaves. Dwarf irises are one of the earliest bloomers in my zone 7 Virginia garden. These irises are only 4-5 inches tall and bloom solitary flowers in February and March. Mine have been in my garden for a long time, nothing bothers them.

J.S. Dijt

J.S. Dijt

Also known as netted iris, dwarf irises (Iris reticulata) are very small bulbs, covered with a fibrous netting. There are many cultivars; flower colors range from light to dark blue or light to dark purple. Preferring full sun and well-drained soil, they thrive in rock gardens, on steps and terraces, in containers, and can be forced to bloom indoors in pots. The flowers can be cut for small desk top vases, bringing early spring cheer to the office or home.

They are available to plant in the fall, along with other bulbs, at local garden centers or through bulb companies. Because they are so small though, buy at least a handful. Plant with roots pointing down, spike pointing up, three inches deep and three inches apart. Hardy to zone 5, they die back in the summer and come back in the spring every year. In my garden, ‘J.S. Dijt’ and ‘Harmony’ have thrived for years with no pests or diseases.

Home for the Holidays: Florist’s Cyclamen

I am sure you have seen the beautiful holiday plant, cyclamen (Cyclamen persicum). Also called florist’s cyclamen, this plant blooms during winter and is a popular gift plant. The flowers, which are high above the foliage, last for several months. Cyclamen is available in a range of sizes, from mini to large, as well as flower colors in magenta, red, pink, and white. Beautiful as it is, it is not an easy plant to grow. Here are tips to prolong the bloom and save for next year. Continue reading