Tag Archives: Roses

Do Japanese Beetles Prefer Some Roses More than Others?

Colorado roses have been attacked by Japanese beetles for several years, leaving behind ravaged foliage and deformed flowers. Curiously though, some gardeners report that their roses suffer little to no damage from the insect. Are some rose cultivars less enticing to the Japanese beetle than others? This was the focus of Colorado State University’s 2016 observational study conducted at Littleton’s War Memorial Rose Garden. In the first year of this multi-year study, the following rose cultivars were not found to be damaged by Japanese Beetles: Angel Face, Debut, Hondo, Joseph’s Coat, Mardi Gras, Picotee, Popcorn, Prima Donna, Ralph Moore, Singin’ in the Rain and White Lightnin’.

Conversely, the following cultivars were observed to have the highest levels of Japanese beetle destruction: Pink Promise, Honey Perfume Whisper, Love and Peace, Day Breaker, Strike it Rich, Cherry Parfait, Eureka, Starry Night, Rainbow Knock Out, Lady Elsie May, Carefree Delight and June Lover.

Adult Japanese beetles destroy flowers at the same time bees are gathering pollen, making their impact even more significant. For this reason, CSU’s study identified roses with high Japanese beetle susceptibility and high visitation by bees. Topping this list were Rainbow Knock Out, Lady Elsie May and Strike it Rich. Also in this group were Prominent, Home Run, Easy Does It, Apricot Nectar, Gemini, Starry Night, Baby Boomer, Sweet Diana, Julia Child, Cathedral, Betty Boop, Mon Cherie and Cloud Dancer.

Early findings suggest that gardeners may be able to lessen damage to roses by planting cultivars that are less attractive to Japanese beetles. It also underscores the importance of close monitoring and care of plants to reduce the effects on pollination. In the future, additional information on why some cultivars are preferred over others is likely to emerge.

This CSU publication provides comprehensive information on caring for plants infested with Japanese beetles, the larvae stage effecting turf and more. An additional bit of advice – it has recently been found that crushing the Japanese beetle does not attract more beetles. So, while we’ve previously been advised to handpick and drown the insect in soapy water, feel free to stomp on them too. Since they are night feeders, they are easiest to find around dusk, when they are about to feast on your plants.

Written by Linda McDonnell, a Denver County Master Gardener

Note: The study cited in this post was presented to the Denver County Master Gardener Association by Dr. Whitney Cranshaw of Colorado State University in May 2017.

Photos courtesy of http://www.pixabay.com

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Under the Denver Sun

Beginnings of a Small Italian Garden

Italy. Hazy grey vistas are punctuated with narrow vertical trees. Nodding sunflowers laze in stony fields.  Knotty ancient thick-trunked olive trees hold forth in blazing sunlight. Window boxes are crammed full of vibrant red Pelargoniums or cascading petunias. Peeling walls, old doors and white sculptures are pierced with long rays. Shadowy evenings are filled with bees humming, and the breeze surprises with soft scents of lavender, roses and rosemary. Fountains play, and nearby the pergolas and arbors anchor verdant vines.  At once the designs are structured yet informal.  Italian gardeners tend to trim, pollard and generally shape many aspects of their plantings so keeping discipline within the freedom of the overall design. How could I bring these colors, textures and smells to a small sunny south-facing Colorado garden?

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Imposing Facade Bramasole, Cortona , Italy

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Roses, Lavender, Hibiscus, and Bees, Bramasole

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Blues in Foliage, Movement in Growth Pattern of Lavender Bed, and Lemon Trees in Movable Containers. Credit Patty Hollis Bramasole Photographs

We actually have some similarities here in Colorado to Tuscany: the purity of the sunlight, the ability to grow many of the same plants, and the often-disappointing soil!  Moreover, in Denver there is a propensity of Italian style houses needing yard work done, so as to create harmony with the home design.
We had this situation: a somewhat imposing stone house, with a tile roof, overwhelming a sad small lawned plot. We needed a plan that captured the essence of Italy. An Italian garden is rigid in some ways, but flowing and full of playful surprises as well. First, I put in the new curving flagstone pathways, then we had a focal point gate inserted in an existing wall (the only big expense), and I marked-out (with garden hoses) the new meandering borders for future flowerbeds.

Spring 2015, I laid six layers of newspaper, then topsoil and finally mulch (begged from a tree felling crew) on the new borders. Meanwhile, we planted the biggest items first so trees were positioned in the remaining grass areas. This stage included three small standard flamingo willow ball topiaries, and we were happy with how their pink spring delicate leaves brought in movement. In June I put in marker flags and then dug holes and planted the bulk of the borders.

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The New Reclaimed Border: Newspaper Layers, Topsoil and Mulch with Roses, Lavender, Speedwell, Tiny Dusty Miller, Boxwoods AND June Hail

From the house foundation to the front this was the order: Spiraea on one side (part sun), alongside large Rose of Sharon shrubs (full sun). Also, dusty pink climbing roses mixed with Russian sage were set-in at the base of the sunny wall. Then Moonstone™ floribundas were the next tall, back layer. Coming forward I placed Veronica (speedwell), and then lavender (both grouped in threes and fives), catmint (in a sometimes boggy drain outlet area), Bonica roses, and in front random plantings of soft grey Dusty Miller (which I planted as a annual but has thrived into this year). Finally, I nestled in boxwoods at the front of the new borders.

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New Garden Gate- Early Days

Boxwoods were intrinsic as a uniting design element, but I worried in this hot aspect that they might not thrive. They have done well so far (after some initial winter bronzing that righted itself) and although slow growing they add dark green shiny all-year round formality. I planted many more this year, and slowly I will add different sizes to bulk out the design. Also, I just put in a mixture of own-root end-of-year bargain miniature roses, in the same soft pink scheme.  Someone else might have chosen to go for more vibrant colors in so much sunshine, but for us the dusty pink and muted blue palette suited and followed our Tuscan inspiration.

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Cosmos: First Year Quick Dramatic Interest with Daisies and Spiraea

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Boxwood, Roses, Catmint, Russian Sage, Climbing New Dawn Roses and Trumpet Vine

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Moonstone Rose Large and Long Lasting

There was also an arid area around a large blue spruce so my latest additions have been barberries, grasses and low growing, tight growth junipers.

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Dwarf Hameln Grass, Barberry and Blue Spruce

Additionally, we have a small curved 270’ pathway that needed a focal point. I had a thriving eight foot Aspen, along with cankers and overnight new saplings.  It did hurt to rip it out, but it needed to be done. Ideally, a hundred year old olive tree was called for. But for a substitute we have just planted a Twisty Baby Black Locust to add the gnarly element that mimics a grand olive tree. I have given it a weekly dose of sugar water to possibly help with rather dramatic transplant shock more information here. This specimen tree should be interesting winter interest too, and we are hoping in time it will produce its lovely large white spring blossom.

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Dramatically Staked Rather Droopy New “Twisty Baby”

 

Recently we were pleased with how things were shaping up, but we still felt our house overwhelmed the plot and we were missing some movement, texture and color. I realized the design was devoid of a crucial element that separates the Italian landscape from any other, and without which Tuscany and even Renaissance landscape paintings would be dull.  The strong narrow verticals dotting all the land, lining the roads to cemeteries and grand villas.  I needed some upward movement.  In lieu of cypress I have planted, somewhat symmetrically, some Blue Arrows and Medora junipers. They have added the strong missing element, and should be interesting in our monochromatic winters.

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Assisi, Umbria Vertical Inspiration

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2017 One of the New Vertical Evergreens

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Whimsy. Perfumed and Perfect

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Structure in the Design, Clipped Hedges and Flamingo Willows.

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Blue Arrow Vertical Defining House with Speedwell & Sweet Drift Rose

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Part Sun Textural Plantings and New Verticals.

Late summer sees our humble garden at its best.  It is textural, perfumed and the air is filled with bees. As the boxwoods grow larger, and the narrow upright junipers extend upwards, the design will strengthen.  But for the moment I am content with the first steps on this project. Once established it has been low maintenance, with little room for weeds to grow. Ideal additions would be a little flagstone wall to step the front lawn, more beds, a sculpture or a sundial, and citrus in movable pots.
Anne Beletic.
A Denver County Apprentice Master Gardener

Appendix : Other Images Showing Details

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Bees and Hummingbirds

List of Main Plants:

Barberry: Berberis thunbergii for winter interest; slow growing  and perfect in front of blue spruce and Spiraea)

Lavender ‘Munstead’: Lavandula angustifolia for bees and constant summer blooming

Lavandin: L. angustifolia x L. latifolia

Russian sage:  Perovskia atriplicifolia  as a foil for roses and kept in check behind them

Catmint ‘Walker’s Low’: Nepeta racemosa covers unsightly gutter and run off area

Dusty miller: Jacobaea maritima gives a lot of bang for the buck and adds amazing light grey and texture to the design; much taller than the 10” I expected!

Speedwell: Veronica longifolia was cut well back in July for a substantial second bloom

Yellow trumpet creeper: Campsis radicans  f. flava Still waiting for flowers- value to be decided!

Junipers:  Juniperus scopulorum ‘Medora’ and Juniperus scopulorum ‘Blue Arrow’

Flamingo willow: Salix integra ‘Flamingo’

Boxwoods: Buxus sps

Black locust : Robinia pseudoacacia  Twisty Baby™

Roses:  ‘New Dawn’ – climbing; ‘Moonstone’™ – floribunda, highest maintenance, has had aphids, rose midge and very bothered by Japanese beetles, but are flourishing at end of summer with massive blooms; ‘Nearly Wild’; Bonica™; Blushing Knockout®; Pink Double Knockout®; Sweet Drift®; Whimsy™ – miniature, amazing fragrance.

Pre-existing:

Michaelmas daisy:  Symphyotrichum novae-angliae

Spiraea  sp. Large and formally cut box shape house foundation plant, dark green leaf and few white flowers

Spindle:  Euonymus japonicus

Rose of Sharon: probably Hibiscus syriacus ‘Collie Mullens– has  very short “giving season” but is glorious August and September.

Semi Arid area under blue spruce tree:

Red barberry:  Berberis thunbergii

Mound grass: Pennisetum alopecuroides ‘Hameln’ – divided and planted late summer, so hoping it will thrive

Juniper: Juniperus squamata ‘Blue Star – hoping to block out bindweed in time

Annuals:

Red fountain grass: Pennisetum setaceum ‘Rubrum’

Verbena  sps – in pots with boxwood 2016

Pelargoniums: Pelargonium peltatum ‘Contessa White’ – ivy’type for window boxes. I didn’t actually succeed in overwintering these and expense prohibited from re-buying, also they were not exactly an ivy geranium in their growth pattern, having only a slight “tip-over”

Other Plantings:

Bulbs, Cosmos, Chinese bellflower – Platycodon grandiflorus-  and ground covers including several Veronicas

List to do in Fall:

Anti-desiccant spray liberally on boxwoods and young evergreens

Wrap trunks of new trees

Twine wrapped around length of blue arrows (so snow doesn’t open the growth)

Collar grafted floribunda roses, pile mulch around other roses

Fertilize remaining lawn

Top-up mulch for general root protection and neatness esthetics (dark brown)