Hort in the Home Landscape A blog devoted to sharing timely horticulture topics and answering the questions of gardeners and homeowners. Sun, 15 May 2005 13:02:08 -0500 https://web.extension.illinois.edu/dmp/eb284/rss.xml Plant of the Week: Perennial Hibiscus https://web.extension.illinois.edu/dmp/eb284/entry_12774/ Fri, 04 Aug 2017 11:15:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12774/ I don't know about you, but I've been noticing that perennial hibiscus plants are looking awesome in the landscape these past few weeks!

So, this week I'm featuring the Perennial or Hardy Hibiscus (Hibiscus mosheutos). Many gardeners are familiar with the tropical hibiscus (Hibiscus rosa-sinensis) that we grow as houseplants in the winter and set outside for the summer, or the shrub hibiscus, better known as Rose-of-Sharon, Hibiscus syriacus. This hibiscus though, is a great addition to the perennial landscape here in Illinois with its hardiness to zone 4.

Perennial hibiscus is traditionally one of the latest perennials to emerge in the spring which always make me wonder if it's coming back or not. But alas, it always does though!

Fast forward a couple of months after spring and hibiscus is now about 4-5 feet tall with gorgeous flowers in my landscape. The mature height of perennial hibiscus can range from 2-8 feet depending on the cultivar. Foliage color can be either green or a nice dark purple like the ones in my landscape.

Flowering typically occurs in July-September with showy, dinner plate-sized, hollyhock-like flowers (each to 4-6" in diameter). The flowers are complete with five overlapping white, creamy white or pink petals with reddish-purple to dark crimson bases which form a sharply contrasting central eye.

This perennial is easily grown in average, medium to wet soils in full sun. It does best in moist, organically rich soils, but does surprisingly well in average garden soils as long as those soils are not allowed to dry out. Perennial hibiscus should be cut to about 3-4" from the ground at the end of the season. Next year, new growth will appear late but will grow quickly.

Learn more here:http://urbanext.illinois.edu/hortanswers/plantdetail.cfm?PlantID=729&PlantTypeID=2

Plant of the Week: Roses and Rose Rosette https://web.extension.illinois.edu/dmp/eb284/entry_12757/ Thu, 27 Jul 2017 10:11:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12757/ International Rose Test Garden in Portland, Oregon and sitting in on a recent program on Rose Rosette virus, my mind is currently on roses. So, Roses it is for this week's Plant of the Week! The fragrance, the beauty, the vase life, they just can't be beat from the view point of a florist and gardener like myself.

According to Missouri Botanic Garden, Rosa is a genus of about 150 species of deciduous (occasionally evergreen) shrubs and climbers noted for their beautiful, often fragrant, single, semi-double or double flowers which are borne singly or in clusters on often prickly stems clad with 5-9 leaflets often having toothed margins.
There really is nothing like the beauty of a rose, but unfortunately, the prevalance of a virus that infects roses has brought about more attention to roses recently, and not for a necessarily good reason. This disease, called Rose Rosette, can be devastating to roses in your landscape if able to spread. Learn more about how to spot it below.

Diane Plewa shared the following in a Home, Yard and Garden Pest Newsletter article about Rose Rosette:

Rose rosette disease was first described in the early 1940s in North America. In the seven decades since, rose rosette has become established across the Midwest and is now found across most of the United States. The causal agent of the disease, a virus, was isolated and identified in 2001. This virus was named Rose Rosette Virus, or RRV.

The symptoms of rose rosette can be striking. Classic symptoms include distortion, discoloration, and overgrowth. Flower petals, flower buds, and new leaves may be elongated and twisted. Multiple small shoots may develop in clusters, forming a growth known as a witches' broom. New growth may be an abnormal red color, with numerous small prickles (thorns) developing rather than the normal fewer, larger prickles. Shoots may elongate quickly, giving the new stems a thick, succulent appearance. Unfortunately, symptoms can vary depending on the variety, age, and condition of the rose host and environmental conditions. Not all symptoms may be present in an infected host.

Symptoms of rose rosette on a rose host infected with RRV. Note the thick, succulent stems, the proliferation of small prickles, and the red color of the new growth. Photo credit: University of Illinois Plant Clinic.

Roses appear to be the only hosts for RRV. Unfortunately, a wide variety of rose groups including hybrid tea, floribunda, grandiflora, and miniature roses appear to be susceptible. Shrub roses, including the increasingly popular Radrazz roses (better known by their registered trademark name, the Knock Out® Rose), are also susceptible. The invasive weed, multiflora rose, is particularly susceptible to RRV. The virus has been used as a biological control of multiflora rose with varying success. Preliminary testing indicates that there may be some rose species that are less susceptible to RRV, but none are currently used in the ornamental industry.

RRV is transmitted from plant to plant in the environment via the eriophyid mite Phyllocoptes fructiphilus. Eriophyid mites are tiny creatures, measuring approximately 0.01 inches in length. They are invisible to the naked eye and require a strong hand lens to be observed. These mites are easily blown by wind currents. They congregate and feed on tender new growth, such as buds and emerging leaves. As they feed, the mites acquire the virus from infected plants, then transmit the virus to healthy ones. How long the rose survives after it is infected is heavily dependent on a number of other factors, including general health of the host before infection. Most roses develop symptoms within 3 months and die within 2 years of being infected. Research indicates that the virus also reduces the cold hardiness of the rose host.

No chemicals have been shown to be effective at either preventing or curing rose rosette. Miticides are not recommended as the mites can quickly re-enter an area all season long, necessitating constant miticide applications.

Cultural management to reduce the spread of the virus includes the following: plant and propagate only virus-free plants; when planting roses, leave enough room between plants that they will not be overly crowded, even when mature; sanitize pruners between cuts; remove unwanted roses, plants that can act as hosts to the virus; and scout rose plantings for early signs of the virus. Unfortunately, many of the telltale symptoms of infection are difficult to distinguish on Radrazz roses as they typically grow quickly and their new growth usually has a red hue.

Symptoms of RRV on a Radrazz rose. Note the red discoloration of the new growth and the terminal witches' brooms. Photo credit: Diane Plewa

Once the virus has gained entry to the host, it becomes systemic and spreads throughout the entire rose plant. If a plant is suspected of being infected with RRV, the entire plant including the root ball should be removed from the landscape as soon as possible. Wrap the above-ground portion of the plant in a plastic bag before removing it to reduce the spread of the mite vector. The infected plant material (above- and below-ground tissue) can be wrapped in a black garbage bag and left in the sun for several days to kill the plant and any mites that may be present. The infected plant material should be burned or removed from the landscape. If the roots are not completely removed, they may send up new shoots. These should be immediately destroyed.

The virus has been found to persist in root fragments left in the soil; however, research indicates that the virus cannot survive in the soil alone. Plants other than roses can be planted into areas affected by rose rosette immediately while roses should not be replanted until all root fragments are removed or decomposed. (Diane Plewa)

Check out the University of Illinois Plant Clinic's Factsheet on Rose Rosette here.
If you're need more information about anything related to roses, the Our Rose Garden website has it all!
Plant of the Week: Naranjilla https://web.extension.illinois.edu/dmp/eb284/entry_12711/ Fri, 07 Jul 2017 09:17:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12711/

This week's Plant of the Week immediately drew my attention while visiting the Sarah P. Duke Gardens in North Carolina last week. The interesting spines caught my eye right away! It's called Naranjilla (Solanum quitoense) and it's a member of the nightshade family, Solanaceae, which includes tomatoes, peppers, eggplant and potatoes.

According to a Purdue Extension article, Naranjilla is a spreading, herbaceous shrub that can get up to to 8 ft high with thick stems in its native habitat, believed to be the most abundant in Peru, Ecuador and southern Colombia.

What I found most interesting of course were the spines on the leaves, which can be few or numerous, occurring on petioles, midribs and lateral veins, above and below, or the leaves may also be completely spineless on some plants. Young leaves, young stems and petioles are also coated with purple hairs.

Paired with 'Campfire' coleus it made for a striking display!

The fruits, which will look similar to tomatoes, have a brown, hairy coat that protects the fruit until it is fully ripe, when the hairs can be easily rubbed off, showing the bright-orange, smooth, leathery, fairly thick peel. The fruit supposedly has a citrus flavor that is described as a cross between lime and rhubarb and the juice is used to make a popular drink in South America. Unfortunately, in our northern temperate climates, these interesting fruits won't appear, so we enjoy it as an interesting foliage plant.

Interested in trying this plant out in your garden next year like I am? I see several sources of seed online and transplants could be started indoors along with your other tomato transplants.

While at the garden, I also came across Solanum pyracanthos, known as the Porcupine Tomato, which was equally as interesting!

Plant of the Week: Butterfly Weed https://web.extension.illinois.edu/dmp/eb284/entry_12679/ Fri, 23 Jun 2017 10:26:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12679/ This week's Plant of the Week is special because it is the 2017 Perennial Plant of the Year! Each year the Perennial Plant Association selects an outstanding perennial to promote and 2017's perennial is Butterfly Weed (Asclepias tuberosa). And it sure is well deserving!
This native perennial is a favorite of mine as a great cut flower, but also as a milkweed that supports the life cycle of the Monarch butterfly. Extension Horticulture Educator, Martha Smith, shared an article earlier this year highlighting the great attributes of this plant which I'm sharing below. Enjoy!

With all the "buzz" about bees and butterflies, the Perennial Plant Association is celebrating a plant known for its ability to support birds and insects, including a beloved North American native butterfly. The Association has just announced Asclepias tuberosa as its 2017 Perennial Plant of the Year™.

Commonly known as butterfly weed, this long-lived and striking perennial is native to much of the continental United States, along with Canadian provinces Ontario and Quebec.

"With vibrant orange, red, and yellow flowers that seem to jump out at you, butterfly weed is a great addition to a sunny garden with average to dry soils," says University of Illinois Extension educator Martha Smith. "As the common name suggests, these plants are butterfly magnets. They also have a medicinal history as a treatment for pleurisy, a common ailment in early colonial times, causing wheezing, coughing, and great pain due to the inflammation of the pleura round the lungs. Asclepias tuberosa reportedly was so effective in treating this ailment it earned the common name pleurisy root."

Butterfly weed is a member of the Apocynaceae or milkweed family. This family includes plants with a milky sap poisonous to most insects. Unlike other milkweeds, Asclepias tuberosa contains little sap. The hairy leaves are 2 to 5 inches long, growing close together as they spiral up the hairy stem. Stems are branched near the top with flat clusters, or umbels, of many showy flowers in late spring through mid-July.

"Butterfly weed flowers are easy to recognize because of their 'five up and five down' appearance," Smith says. "Each flower has five colorful petals that hang down and five upright curved petals called hoods, each possessing one orange horn. When cross-pollinated, a dry fruit, called a follicle, forms. The mature follicle opens along one side to disperse the seeds."

Smith recommends deadheading Asclepias tuberosa to prevent reseeding, to keep the plants more attractive, and to promote a second flush of color later in the season.

Asclepias tuberosa makes excellent, long-lasting cut flowers. "Cut stems when more than half the flowers are open; buds do not open well once the stem is cut. Searing the cut end is not necessary to prevent sap from seeping out of the stems. Instead, cut flowers have a good vase life if they are immediately placed in warm water after cutting and either placing stems in a refrigerator for 12 hours or transferring the stems to cold water. This process eliminates what little sap may be produced," Smith notes.

Butterfly weed is hardy to zones 4-9 and reaches 2 to 3 feet high with a 2-foot spread. Smith cautions gardeners to be patient, as butterfly weed is slow to emerge in the spring. Young plants grow from a single central stem, but with age, plants will develop additional shoots at the base. Mature plants do not transplant well, although they can be divided carefully in early spring before new growth begins. "Dig carefully," Smith says, "but if enough root is left behind, they will regrow. Don't cut back in late fall, rather wait until early spring. To prepare young butterfly weed for the winter, put mulch down around them to prevent frost heaving."

Butterfly weed is often grown from seed. Experts report 50-80 percent germination if fresh cleaned seed is used. "If germination does not occur after 3 to 4 weeks, provide a 2 to 4 week cooling period," Smith says. "Collected seed will result in flower color variation. To ensure color, purchase seed from a reputable source. Propagation through root cuttings can be used to ensure quality from forms showing merit. Cutting back once, early in the growth cycle, will promote compact growth."

Since Asclepias tuberosa is a native prairie plant, butterfly weed is quite comfortable in meadow gardens, native plantings, and wildlife sanctuaries, but it is finding its way into semi-formal to formal urban gardens. Smith suggests planting it in large masses, for an unrivaled display of eye-popping orange flower color. Orange butterfly weed pairs well with summer blooming Phlox, Hemerocallis sp., Liatris spicataEchinacea sp., Salvia sp., and most June/July sun-loving perennials. Another bonus is that if the garden is visited by deer, they will leave Asclepias tuberosa alone.

Many bees, wasps, ants, butterflies, and beetles visit butterfly weed, as well as hummingbirds. All members of the milkweed family serve as larval food for the monarch butterfly (Danaus plexippus), queen butterfly (Danaus gilppus), and the milkweed tussock moth (Euchaetes egle). "Let them munch on butterfly weed and you will be rewarded with these 'flowers of the air,'" Smith says.

Plant of the Week: Asiatic Lilies https://web.extension.illinois.edu/dmp/eb284/entry_12610/ Tue, 13 Jun 2017 14:08:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12610/

As a floral designer, this week's Plant of the Week is a favorite of mine: Asiatic Lilies (Lilium sp). While visiting the gardens on the Macon County Master Gardener Garden Walk this past weekend, I noticed several gardens with Asiatic lilies blooming in full glory.

One of the earliest and easiest to grow of all the lilies, Asiatics are beautiful, but generally lack the heavy fragrance that others, like Oriental lilies, can possess. They flower in early summer with 4-6 inch diameter flowers in colors like reds, pinks, oranges, yellows, lavender and white with mostly upward facing flowers.

Lilies are known for their height, some of which exceed 5 feet and require staking. But according to Missouri Botanic Garden, more recent development of dwarf hybrids called Pixies, standing only 18 inches or less, offer the chance to move lilies closer to the garden edge, intermix with other flowering plants and use in containers. Pixies are more difficult to find but should be more available in coming years.

Lily bulbs are typically offered for fall planting or can be found in garden centers as potted plants, ready to plant this time of year. Asiatics are fairly easy to grow, with the one requirement of a well-drained bed. Take extra time to work the soil amending with peat and compost, up to one-third each by volume. A recommended planting depth is 6 to 8 inches, spacing plants at least one foot apart. If your soil is not as well-drained, you may away with planting the bulbs a little higher.

Like with other bulbs, such as daffodils, new bulbs are produced each year and when the plant becomes too crowded, flowering will drop off. If this happens, in August before the leaves yellow, dig the bulbs, divide and replant or store the bulbs in a cool, dry place until spring.

Asiatic lilies are best cut for enjoying in a vase, just as the flowers start to show color and open up. They can last in a vase filled with water and floral preservative for as much as 10 days in the right conditions. Change the water frequently to extend the life of flower. Be sure to also remove the anthers (pollen structures) as the lilies open up, as this may stain clothing or other materials.

Using Cut Flowers to Bring the Garden Indoors https://web.extension.illinois.edu/dmp/eb284/entry_12630/ Fri, 09 Jun 2017 09:22:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12630/ As gardeners, many of us like to relax in the backyard, taking time to enjoy our beautiful flowers, but why not bring those beautiful bloomers indoors to enjoy? Many showy flowers, grasses, and foliage are available to interplant into your existing garden beds, allowing you to harvest throughout the seasons.

The most important thing to consider when choosing a plant for a cut flower garden is the vase life of the flower. Some flowers simply do not last long once cut from the plant. Daylilies, for example, have a very accurate name; the flower only lasts for a day, making it a poor choice for a cut flower garden. On the other hand, oriental lily, a perennial bulb, has a much longer vase life.

Listed below is a selection of plant choices for a long-seasoned cut flower garden in Illinois. These annuals, perennials, bulbs, grasses, and shrubs will be easy to grow and the vase life of the flowers will be at least a week in most cases.

Annuals may be easily started from seed indoors to create transplants or may be direct-seeded right into the garden. Easy to grow examples include zinnias, strawflower, celosia, gomphrena, amaranth, cosmos, blackeyed susan, and sunflowers.

Bulbs make great additions to an existing garden bed that needs a bit of color. Spring flowering bulbs are perennials and are planted in the fall. Summer bulbs are planted in the spring and dug up at the end of the season. Both types of bulbs can serve as beautiful cut flowers. Spring flowering bulbs like tulips, daffodils, and lily of the valley are all long-lasting cut flowers. Dahlias and gladiolus are beautiful summer bulbs that are worth the effort of digging up at the end of each season.

Stagger out your flowering times when selecting your perennials to have flowers always available for cutting. Hellebores, bleeding heart, peonies, iris, liatris, purple coneflower, eryngium, poppies, astilbe, clematis, yarrow, and sedum are all reliable options.

Foliage plants, grasses, and shrubs
These plants may not have showy flowers, but they add a unique texture to your garden arrangements. Plant lamb's ear, dusty miller, scented geranium, hosta, Solomon's seal, coral bells, miscanthus, northern sea oats, beautyberry, smoke bush, spirea, Japanese pieris, and ninebark in your garden to have a ready supply of foliage and textural elements to add to your vase.

When to Cut

The best time to cut flowers from the garden is in the morning, before the dew has evaporated. The next-best time to cut flowers is in the early evening. Be sure to place your stems into water with a floral preservative as soon as possible after cutting. Floral preservative packets can be found at your local florist. Remove any foliage from the stems that will be under water, and place your vase in a cool location, away from direct sunlight or drafts. Change your water every few days, adding a new floral preservative packet each time, to ensure a long vase life for your beautiful garden arrangement.

Plant of the Week- Penstemon https://web.extension.illinois.edu/dmp/eb284/entry_12606/ Wed, 31 May 2017 11:56:00 +0000 https://web.extension.illinois.edu/dmp/eb284/entry_12606/ This week's Plant of the Week has always been a favorite of mine. Beardtongue (Penstemon digitalis) is a native perennial you'll find growing in prairies, fields, wood margins, open woods and along railroad tracks throughout the state. At a local garden center, you'll also find a variety of great cultivars available.

This clump-forming, perennial typically grows 3-5' tall and has wonderful white, two-lipped, tubular flowers borne in panicles blooming in mid-spring to early summer. The tall height of these flowers mixes beautifully with many other perennials in the landscape and sways wonderfully in the wind. One of the many reasons I love this plant!

Several species of Beardtongue can be found in the garden, but Penstemon digitalis is a pretty solid performer. 'Husker Red' is a cultivar that you see very commonly which has beautiful dark purple foliage and is slightly shorter that the straight species. And it was the Perennial Plant of the Year in 1996!

'Pikes Peak Purple' is a hybrid variety that blooms most of the summer with large concord grape-purple flowers. Great for hummingbirds!

Whichever cultivar you decide, consider adding this wonderful perennial to your landscape!