Oso Easy Cherry Pie rose. Photo courtesy Proven Winners
As rose troubles continue to plague gardeners, we will look this week at a few more common problems. Last week, we covered black spot, anthracnose, rose mosaic virus and rose slugs.
Japanese beetles tend to congregate on the flowers, buds and leaves of roses and hundreds of other plants. The beetles skeletonize the leaves. Photo courtesy Kansas State University Extension
Japanese beetles. Pretty soon, it will Japanese beetle season, that is if any of the pupae survived the winter to emerge as the attractive, green metal bugs.
These bugs skeletonize the foliage of roses and 400 other types of plants. They also dine on flower petals. Frequently, systemic insecticides are recommended to control Japanese beetles, but these products are nonselective, meaning they kill bees, butterflies and other pollinating insects along with bugs we don’t want. Try these methods instead:
- Remove any damaged leaves and flowers and soon as you notice them. Holey leaves and chewed petals are like neon signs and attract more beetles to the feast.
- Spray the plants with a strong stream of water to knock off the beetles.
- In the mornings, knock the beetles into a bucket of soapy water and dispose.
- When startled, the beetles fall to the ground. Take advantage of this by placing newspapers or cloth under the roses and shake the plants. Slide the bugs from the paper or cloth into a bucket of soapy water and dispose.
Although not deadly, powdery mildew weakens a plant, making it susceptible to other diseases or insects. Photo courtesy University of Kentucky Extension
Powdery mildew. Besides roses, a lot of plants get this fungus disease, including lilac and garden phlox, with some being more susceptible than others. This disease creates a whitish or grayish powdery coating on the foliage, stem and flower buds. Although not deadly, it is unsightly and may weaken the plant.
To control this disease, plant roses in full sun and with good air circulation. Once mildew hits, there’s nothing that will get rid of it. Fungicides may keep the disease from spreading to healthy leaves. Remember that fungicides are particularly deadly to bees, so always follow the label directions.
Webs on plants are another sign of possible spider mite infestation. Yellow or orange stippled leaves are another common symptom.
Spider mites. Spider mites cause tiny orange, white or cream dots on the leaves, called stippling. Mites may show up when it’s hot and dry. Knock them off with a strong spray of water from the hose.
A hard spray from the hose is a quick and easy way to knock aphids off of roses and other plants without the need for insecticides. © Dreamstime.com/Armando Frazao
Aphids. Sometimes called plant lice, these slow moving insects suck the life out of plants, causing distorted leaves and flowers. Aphids can be lots of different colors and are easy to see. Control with a hard spray of water from the hose. There are lots of predatory insects, such as lady beetles, that feed on aphids, so a non-selective insecticide is not usually recommended.
Roses may have other problems, so look for disease- and insect-resistant plants and know what you have before you treat it. And remember, a few blemishes are nothing to worry about. Mother Nature is not perfect, either.
Vegetables and fruits
Double Pink Knock Out Rose. Photo courtesy Star Roses
Questions about sick roses continue to fill my inbox and the aisles of garden centers.
Many roses, including the tough-as-nails Knock Outs, did not rebound after our brutal winter. Several of those that did make it through don’t look great.
There’s some thinking that the roots of the plants were damaged by the severe season. They are no longer able to support adequately the top growth, rendering the plants weak and susceptible to insects and diseases.
Cutting the roses back hard – close to the ground – is what we did in spring, but if the plants still are not thriving, consider cutting back again. This reduces the top growth and allows the roots to heal and grow. Fertilizing isn’t necessary, but a good dose of compost around the base of the plant will help.
In the first of a two-parts, here are some common problems we’re seeing:
Rose slug damage on leaves. Photo courtesy Purdue Plant and Pest Diagnostic Lab
Rose slugs. These are the larvae of the rose sawfly. They are a pale green and are usually present in spring and as they dine, they give roses a stained-glass look.
Pear slugs. The damage from these larvae is similar to rose slugs, but appears in summer.
These insects can defoliate roses and give the plant a burned look. Be vigilant about inspecting the undersides of leaves. Remove any larvae or use a strong spray from a hose to knock them off.
Rose mosaic virus leaves tracks in the leaves, eventually turning them yellow from a lack of chlorophyll. Photo courtesy Kansas State University Extension
Rose mosaic. This virus can be spread by insects as they munch and move among the plants. We can spread it, too, with tools that are not cleaned with a 10 percent bleach solution after each use on a sick plant. The disease stunts the growth of roses and causes mottled leaves, which lose their green becoming chlorotic.
Once a rose is infected, you can remove affected branches, but the disease remains in the plant. Eventually, the rose will be weakened and likely will die. Consider removing and destroying affected plants to keep the disease from spreading to healthy roses.
Black spot is the most common disease on roses. Eventually, it can weaken and kill the plant. Photo courtesy Purdue Plant and Pest Diagnostic Lab
Leaf spots. Roses can be affected by two different leaf spots: black spot and spot anthracnose. Black spot, which appear on the top of the leaf, is probably the most common disease on roses. Eventually, the leaves turn yellow and drop. This disease weakens the plant.
Anthracnose is an opportunistic disease that may show up in hot weather.
Photo courtesy Purdue Plant and Pest Diagnostic Lab
Anthracnose spots may show up in really hot weather. The spots are fuzzy. Leaves turn yellow and drop off.
Make sure that any pesticide you select is labeled for the problem you have.
Next week, we’ll look at a few other common rose problems.
A pot of Lanai Red verbena, Whirlwind White fan flower, white lantana and Angleface Blue angelonia herald the patriotic hues of the Fourth of July.
© Jo Ellen Meyers Sharp
If you are looking for a patriotic pop of blooms for the upcoming Fourth of July holiday, here are some suggestions.
First, go with premium annuals. These are usually in 4-inch (or larger) pots and cost considerably more than bedding plants. But premium annuals give you a lot of bang for your buck because they already have good size and maturity, making them showy right from the start.
Garden centers will stop selling bedding plants soon, if they haven’t already. Growers are no longer producing these because once they reach a certain size, it’s too hard to keep marigolds, petunias, vinca, salvia and other bedding plants alive in those tiny four- or six-pack plastic trays.
As the season progresses, even the premium annuals start to look a little scraggly. Because they are in larger pots, the plants can can be cut back, fertilized and allowed to rest for a couple of weeks before they start to rebloom, making them worthy of space on the garden centers’ tables and your deck or patio. Rehabbed plants will have a tighter growth habit, too, with more flowers. A premium annual costs $4.50 to $5 each.
Keep in mind the components of a container. Thriller is the focal point or dramatic plant. Fillers are mounded plants that take up space, usually at a mid-level in the pot. Spillers cascade over the side of the pot.
So, what would be good choices for your red, white and blue patriotic pot? Here are some suggestions of annuals for full to part sun locations.
- Tall red salvias (S. splendens) work well as a centerpiece in a container
- Red geraniums serve as fillers and red petunias, verbenas are fillers and spillers.
- Victoria White mealycup sage (Salvia farinacea) can be used as a centerpiece plant. These get 15 to 18 inches tall and bloom all summer.
- White verbena, petunia, lantana, fan flower (Scaevola) all have mounded, trailing habits. Diamond Frost euphorbia fills the pot with tiny starts.
- Royal Velvet Supertunia, which is probably the best selling petunia on the market. The deep purple-blue flowers didn’t lose their scent during the hybridizing process, either.
- Victoria Blue mealycup sage adds nice height as a centerpiece in pots.
- Angelface Blue angelonia looks like 18-inch tall stalks of orchids. Use as a centerpiece or thriller in a pot.
‘Maui Sunset’ canna, under planted with ‘Kong’ coleus, strikes a dramatic pose in the garden.
© Jo Ellen Meyers Sharp
When I was a little girl, I’d trek down the alley to my great grandmother’s house a block away. Her side yard was a gardener’s bounty, with a circle of tall red cannas at the center. Whenever I see these stately plants, I think of her and her garden.
Although cannas (Canna) are an old-fashion flower, they provide a trendy, tropical feel to the garden, deck, patio, porch or balcony. Ranging in height from about 2 to 6 feet, they are as dramatic in the ground as they are in pots.
A canna is a rhizome, and can be found already growing in pots in garden centers this time of year. Or, rhizomes can be purchased at garden centers in early spring in a package or through online or mail order retailers. Pot these up in March to get the growing process started before transplanting outdoors in mid to late May.
Look for virus-free rhizomes and plants. For the last 10 years, cannas have been troubled by one of three viruses, spread, the experts say, by aphids. The virus can cause malformed leaves or flowers and create speckles or streaks in the foliage. When buying canna plants, make sure they are symptom free.
The fact that cannas have red, yellow, orange, pink, off-white or speckled flowers and that hummingbirds like the blooms is sort of a bonus. To many, the real beauty of the plant is the lush foliage. Depending on which cultivar you have, the leaves will be green, purple, golden or striped.
Cannas are tough plants and do best when planted in full sun, but are quite tolerant of shadier locations. They can take it wet or dry, but prefer soil that is well drained and evenly moist. Cannas also can be planted or grown in pots in the margin or edge of ponds or water gardens. The blue-green leafed cannas seem best suited for pond planting.
There’s nothing quite like a canna leaf striped with green, red, purple or yellow, backlit by the late afternoon sun. It just screams tropics. Flowers and leaves can be cut for indoor arrangements.
After the tops are killed by cold temperatures, remove the foliage, dig and dry the rhizome and store in a cool, dry place. Pot up next spring for another season of beauty.
‘Blue Star’ Japanese aster sports light blue flowers throughout the summer.
© Jo Ellen Meyers Sharp
Don’t you love it when you find a new plant to try?
That’s how I felt when I found the perennial ‘Blue Star’ Japanese aster (Kalimeris incisa) sitting and blooming by itself on a garden center table a couple of years ago, late in the season. Of course, I bought and planted it.
Last weekend, I found another ‘Blue Star’ kalimeris sitting alone on a garden center bench. Yes, I bought it and plopped it right next to a ‘Blue Star’ that I planted two years.
Aster is a good description for the 1-inch wide flower with pale blue petals and yellow center. But unlike the sprawling, late-blooming asters (Symphyotrichum) we’re familiar with, this one stays upright and blooms pretty much all summer.
The Missouri Botanical Garden says this is a ‘tried and trouble-free’ plant in its landscapes, and I can second that opinion.
Grow ‘Blue Star’ in full sun or part shade. The leaves are thick, making it more tolerant of drought. This plant does fine in well-drained clay soil and Indiana’s hot, muggy summers. ‘Blue Star’ gets up to 18 inches tall, spreading to form a nice clump 18 inches wide. It blooms from June into September. (Plant native asters, too, for monarchs and other critters looking for nourishment late in the season.)
Rose troubles continue
If your roses weren’t killed by snow-mageddon, they may be under attack from rose slugs, aphids and spider mites.
Spider mites make yellowish or orange dots on the leaves. The veins of the leaves are green, but the tissue in between is chlorotic – pale green or yellow. Rose slugs munch holes in the leaves and sometimes completely defoliate the plant. Roses will likely releaf once the insect is brought under control. Aphids, too, suck on plants, causing malformed buds, leaves or stems.
The best defense can be found at the end of the hose. A strong spray of water can knock of many aphids, mites and other insects, reducing or eliminating the need for insecticides or miticides. Other controls include:
- Snip off any damaged buds or leaves.
- Remove spent blooms to reduce hiding places for thrips, which are commonly called rose slugs. Removing spent blooms also reduces the hiding places for Japanese beetles. These beetles prefer plants in the rose family, which includes fruit trees and many ornamental trees and shrubs.
- Neem oil, summer horticultural oil and spinosad are environmentally friendly products that control for insects. Always read and follow the label directions.
Plants growing in containers, such as these at Sullivan Hardware & Garden near 71st and Keystone in Indianapolis, can be transplanted any time you can work the soil. (C) Jo Ellen Meyers Sharp
- Houseplants will need more water and fertilizer during summer growing period.
- Prune spring-flowering shrubs within a month after blooms fade.
- Supplement water as needed. Most newly planted stock needs an inch of water every week or 10 days. Established trees, shrubs and perennials can go several weeks without supplemental watering.
- Remove faded blooms from peony, iris, delphiniums and other spring perennials.
- Container-grown stock, including shrubs, trees, perennials and annuals, can be planted any time.
- Continue planting gladiolus for successive blooms.
Vegetables and fruits
- Discontinue harvest of asparagus and rhubarb in mid-June to allow foliage to develop and store food reserves for next year. Fertilize. Water when dry.
- Blanch (exclude from light) cauliflower when heads are 2-inches in diameter. Tie leaves up over the developing heads.
Broccoli head ready for harvest. Photo courtesy Purdue University
- Harvest spring plantings of broccoli, cabbage and peas.
- Plan your Halloween pumpkin. Determine the days to harvest for particular cultivar and count backward to find the proper planting date.
- Remove cold-season plants, such as radish, spinach and lettuce, as they bolt or form seed stalks.
- Every week or 10 days, continue planting carrots, beans and sweet corn for successive harvests.
- Do not be alarmed by June drop of tree fruit. It is a natural thinning process. If needed, help nature by thinning fruit to 6- to 8-inches apart and propping heavy branches.
Current Twin Oaks resident John Herbst selects, places and tends plants in the garden. Photo courtesy Indiana Historical Society
A tour of Twin Oaks next weekend allows visitors to get a peek at the history of two of the best-known families in Indianapolis.
Twin Oaks is the former home and gardens of Ruth Lilly, great-granddaughter of Eli Lilly, founder of the pharmaceutical giant. It was built in 1941 for the family of Lyman S. Ayres II, grandson of the department store founder.
The gardens were designed originally by Frits Loosten (1909-1989), a famous Indianapolis landscape architect. He redesigned them in a more European-style garden when the Ayres sold the property to Ruth Lilly’s father, Josiah K. Lilly in the mid 1950s.
Today, Twin Oaks is the residence of John Herbst, president of the Indiana Historical Society. It also serves as the society’s hospitality center, where its paintings and other art are exhibited. A fundraiser to support the society’s education programs, this is the first time Twin Oaks has been open to the public.
“What has been great for me as a gardener is to restore these historic gardens designed by one of our great landscape designers, and bring them back to life,” said Herbst, an award-winning gardener who likes to get his hands dirty. “I have wonderful bones to work with, extensive white brick walls, bricks and slate paths and terraces, and two ponds.”
The property is owned by William and Laura Weaver, the third generation to operate Weaver Popcorn Co. Inc., based in Van Buren, Ind., The Weavers purchased Twin Oaks from Ruth Lilly’s estate and leases it to the society to manage.
Herbst has done all of the plant selection, placement and much of the planting. “The Kitchen Garden is totally my labor. As I am working out there, I also feel that Ruth Lilly would approve, as she loved flowers and the gardens here. It was a great enjoyment, for her for many years, to be taken through the gardens when the weather was nice,” he said.
Tour of Twin Oaks Home and Gardens
11 a.m. to 6 p.m., June 6 to 8
555 Kessler Blvd., West Drive
Parking with shuttle service at Fox Hill Elementary School, 802 Fox Hill Dr. T
ickets: $18 in advance; $20 tour days. Children 3 to 12, $5.
For details: www.indianahistory.org
Inaugural Celebration in Fishers
The Friends of Heritage Gardens at the Ambassador House and the city of Fishers are sponsoring Fishers Heritage Garden Celebration June 7 and 8. The keynote speaker is Pearl Fryar, the well-known sculptor of plants and subject of the 2006 documentary ‘A Man Names Pearl” (pearlfryar.com) Fryar will give programs at Ambassador House and at the Nickel Plate District Amphitheatre.
It is common for a narrow strip of soil to surround the patio. This strip was widened to accommodate upright yews and hydrangeas for privacy and color.
© Jo Ellen Meyers Sharp
As we head outdoors for race weekend and Memorial Day, here are a few tips on how to spruce up your patio or deck to add a little beauty to the fun.
In general, we tend to have narrow strips of dirt around the patio — barely 2 feet wide, so suggestion number one would be to widen the planting area. Planting a 4-foot wide shrub in that 2-foot space turns into a pruning chore.
Making the planting area 4 to 6 feet wide not only allows for a broader selection of plants, it also is more in scale with the patio, deck and house. And while carving a larger planting bed, give it a few curves rather than straight lines.
When it comes to decks, a common mistake is to use plants that are too small. Plants need to be in proportion to nearby structures, whether it’s the house, garage, deck or patio. Tiny plants can get lost in the mass and size of nearby structures. Planting areas around decks need to accommodate the height and width of plants that will camouflage footings, posts, beams and other structural and construction materials.
Be sure to read the plant tags to make sure your selections will thrive in the horticulture environment you have, such as sun or shade or wet or dry soil. Always allow for the mature height and width of the plants you select.
Add containers filled with annuals, perennials, small trees or shrubs, herbs or maybe even vegetables or small fruit, recommends Altum’s Horticulture and Landscape in Zionsville, in a recent newsletter.
“One of the fastest and most flexible ways to transition into summer. Wipe down your containers and fill them with fresh potting soil. Or pick a pretty new pot or two for a focal point. We also love repurposed containers like galvanized tubs, weathered buckets and troughs. Flea markets and garage sales are where we find some of our favorites. Just remember to add a hole for drainage,” the newsletter says (www.altums.com).
Containers not only add spot color, they also serve as boundaries and soften corners. Cluster pots for even more impact. Water as needed and regularly fertilize plants in containers for the best show.
‘Little Joe’ Joe Pye weed. Photo courtesy perennialresource.com
Sure, weed is part of its name, but this plant is one of the best for attracting bees, butterflies, other pollinating insects and hummingbirds.
Plants called Joe Pye weed is a big family with lots of nearly unpronounceable names. Recently, the name of the common Joe Pye weed was changed from Eupatorium to Eutrochium. The Chicago Botanic Garden has evaluated most of this family during the past decade and found many garden-worthy candidates in this group of native plants.
“Joe-Pye weeds and their relatives are underrated native plants that possess many great garden qualities,” wrote Richard Hawke, plant evaluation manager at the CBG. “Large airy inflorescences and handsome foliage grace an array of plant sizes. These long-blooming plants are invaluable for attracting an assortment of butterflies to the late season garden.”
Joe Pye weed does best in full sun, but tolerates light shade. It thrives in soil that is more moist than dry, so water as needed. Some Joe Pye weed family members self sow, so deadheading – removing spent flowers – will help reduce that. Cut back to the ground in late winter.
Here are the five-star earners in the CBG trials. Chicago-area bloom times are provided, but here in central Indiana, they might be a slightly earlier.
‘Chocolate’ (Ageratina altissima sometimes listed as Eutrochium rugosum) has 3-inch wide white flowers atop 36-inch tall stems. The undersides of the leaves are a dark purple or brown, giving it the chocolate moniker. The foliage, which has excellent mildew resistance, is not that spectacular, but the plant size makes it serviceable in the garden from early September to late October.
‘Little Joe’ (Eutrochium dubium) has purple, flat-top flowers that get up to 5-inches wide. It’s 48- to 60-inches tall. This clump grower blooms from early August to mid September and shows excellent mildew resistance.
‘Carin’ (Eutrochium dubium) has pale pink flowers that get up to 9 inches wide. It blooms from early August to early September, and may get up to 85 inches tall and has excellent resistance to mildew. Hawke calls these tall Joe Pye weed titans, and recommends planting them in the back of a perennial border. Titans also could be planted as a late-season specimen or focal point.
‘Bartered Bride’ (E. fistulosum f. albidum) is another tall beauty, reaching up to 90-inches tall. The 9-inch wide white flowers start blooming in late July and continue into September. It exhibited good resistance to mildew. Here’s the full report.