KTRS 550 Inside Out Show Plant of the Week July 25 2009 Diana Rose of Sharon

'Diana' Rose of Sharon (Hibiscus syriacus )


The 'Diana' Rose of Sharon, Hibiscus syriacus 'Diana', is a strong upright growing sun lover reaching 5-12’ tall with giant white hollyhock flowers early to midsummer till mid-to-late fall! She does tolerate some shade, poor soil and both high and low moisture. This makes her a perfect addition to the edge of a rain garden in the sun or part shade where the soil is not soggy!

Care Factor Rating: 1 (must be watered regularly till established and does not require pruning! She does tolerate a once a year non-selective pruning to1/3 if shaping is desired, otherwise remove only the occasional damaged or dead branch)

This show stopper has an exceptionally flowering period. This is because she is a sterile triploid that produces very few if any seed pods. With this selection, there is no longer any significant reseeding issue as there might be with many other selections. She truely is a non-invasive native landscape friendly companion!

H. s. ‘Diana’ is especially lovely when planted in multiples, looking almost like a set of triplets, she can also be planted in larger numbers to create a screen or border. I particularly love this selection when used where it can be enjoyed in the evening landscape. The flowers are exceptionally large and stay open at night. She is also great for emphasizing the white accents of your home's trim as well as compliment any color pallet. This “bride white” version of this old favorite is very heat and humidity tolerant!

There is an occasional report of some susceptibility to blight, canker, rust, leaf spots. Aphids tend to cluster on new growth and can be controlled with regular hosing off with water. Scale, whiteflies and Japanese beetle are reported as occasional issues as well.

Photo Credit Tammy Palmier

KTRS 550 Inside Out Show details July 25 Tomato Hornworm and Bagworm

July 18th Inside Out radio show questions included request for information on the Tomato Hornworm so I have included some information and links about this common garden visitor and this picture. Watch for information on bagworms next post!

This week Jim announced we are starting a new segment "Dah Bug Of The Week" during which Don (Rolling Ridge) will call in and discuss control methods. This week they discussed Bagworms. So for those who missed this week and want to play next week- Call in next week with this for your answer as to what was "bugging" Jim McMillian!

Here is some information on Tomato Hornworm (see pic)

This home gardener headache is native to the United states, and is commonly found in Missouri. This insect is not a major problem for commercial farms . However the larvae is a frequent problem in home gardens.

Tomato hornworms feed only on the nightshade family which includes tomato plants and all its its relatives including these easy Missouri veggies: eggplant, pepper, and potato.

There are many " weeds" that belong to the nightshade family also including: horsenettle, jimsonweed.

Check weekly for this common garden visitor as 1- 2 generations are reported for this insect each year in Missouri the upper Midwest. Frequent viewing of the garden allows for hand picking as the prefered organic method of control. Many chemicals and even Bt (Bacillus thuringiensis) can kill any butterfly larva in the garden. This insect is parasitized by a number of insects. One of the most common is a small braconid wasp. Larva that hatch from wasp eggs laid on the hornworm feed on the inside of the hornworm until the wasp is ready to pupate. The cocoons appear as white projections protruding from the hornworms body. If such projections are seen, leave the infected hornworms in the garden. The wasps will kill the hornworms when
they emerge from the cocoons and will seek out other hornworms to parasitize.

Listeners- Today's featured insect discussed by Don and Jim was BAGWORM - watch for details on this bug in future posts!

Visit this link for more information:

http://images.google.com/imgres?imgurl=http://www.vegedge.umn.edu/IMG/Tomato/2005Cotesia2.JPG&imgrefurl=http://www.vegedge.umn.edu/vegpest/hornworm.htm&usg=__VpTXFRnC9RPIvJdusJdCekFhwoo=&h=768&w=1024&sz=406&hl=en&start=6&um=1&tbnid=ptRkxq1nzQCjdM:&tbnh=113&tbnw=150&prev=/images%3Fq%3Dtomato%2Bhornworm%26hl%3Den%26sa%3DN%26um%3D1

KTRS 550 Inside Out Show Plant of the Week Hydrangea paniculata Tardiva July 18 2009

This sweet reliable blooming Hydrangea paniculata cultivar blooms every year in Missouri late summer till fall on new wood!

H. p. ‘Tardiva’ has a strong upright posture and fairly bold leaf texture. It has the potential to reach 15’ tall but can be easily maintained at 8’-10’. It has good vigor and is tolerant of both drought and clay soil but looks its best when it has adequate moisture and is not drought stressed. It likes a little shelter from the afternoon sun but with adequate moisture is performs well in full sun

This hydrangea is attractive to butterflies, especially as the blossoms first open. The casual clusters of white flower offer an informal but tidy appearance that is attractive at every stage. I love the kaleidoscope of muted colors as the petals fade to a blush of dusky rose with an occasional violet hue and then to a light cinnamon toast.

Care Factor Rating: 2 ( must be watered regularly till established and requires only one non-selective pruning occasion)

Grow this easy “urban friendly” hydrangea “green” by placing it on the edge of a rain garden where its roots can access the collected moisture without standing it directly in soggy soil. It has few if any significant pest problems and is frequently listed as Japanese beetle resistant. Hydrangea Tardiva’s best time to prune is early spring just before leaf buds emerge.
Click here for more images:

Ledge and Gardens

Missouri Botanical Garden Plantfinder

Showy Primrose -Not So Showy Now

I have had years of growing - and at times enjoying ( at at times fighting) this Missouri Native.

This perennial plant is useful only when correctly sited. Although it has a long blooming period and pretty pink flowers, it can become an nusiance in many situations. I enjoy many of the less agressive members of this species that have allowed me to be more energy efficeint!

While in flower, the foliage breaks out in a rash of blochy spots that turn red, run together and eventually offer a spoiled worn foliage look that looks tattered the rest of the season.

It happens annually, regardless of hot or cool weather, fungicide applications and moisture levels. The foliage "ripens", colors (like it is fall) gets a tattered look with spotting and browning.

Since I do not use chemical controls, I have agressivly cut back all the foliage and done extreme clean up ( making sure as much folage is removed and not left to lay on the ground) It usually resprouts, with slightly cleaner foliage. The plants continue to flower annually and return relaibly without any obvious loss. As a matter of fact- I would have been grateful for some decline as this colonizer is tough!

(Watch for "Tough Enough" blog entry about agressive Missouri Natives!)

Here I have listed just a few foliar diseases that affect this plant:

Cucumber mosaic virus
Sclerotinia blight
Phytophthora & Cylindrocladium diebacks
Leaf spots of several sorts attack but shouldn't be serious.

Infected leaves can be picked off.

Powdery mildew coats the leaves with a white powdery growth.
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http://www.cps-scp.ca/download/cjpp-archive/Vol16/CJPP16(1)15-22(1994).pdf

Garden Corner Green Event Worth Checking Out

Perennial Plant Symposium—The 27th Annual gathering of members of the Perennial Plant Association comes to St. Louis for a week of programs, discussions, garden tours and an industry trade show. The symposium is geared for green-industry professionals, but includes a day of programs for master gardeners and other serious gardening enthusiasts on July 20th called Perennials in Design Seminar: A Potpourri of Plants, Design, and Arrangements. This program features 6 nationally acclaimed speakers. For details, visit http://www.hortco-op.org/ or call the PPA at (614) 771-8431. Early bird registration is just $69 and includes all presentations and beverage breaks. Full-time studens may pre-register for $25.

http://perennialplant.org/resourcefiles/2009Sym.pdf

Bored With Blaming Emerald Ash Borer for Everything

Hello-Emerald ash borer (Agrilus planipennis, EAB) is not the only wood-boring insect
that attacks ash trees!

There are several native clearwing and roundheaded borers also
commonly infest ash.

It is important to be able to distinguish EAB infestations from those of native borers. Every declining or dead ash tree will be at some point colonized by native borers, which attack weak, dying, and freshly killed trees. Visit this website for more information: http://ashalert.osu.edu/userfiles/native_borers.pdf

Watch for upcoming entry about other green insects that might make you wonder: Is this an Emerald Ash Borer?

KTRS 550 Inside Out Show Plant of the Week July 11 2009

Lagerstroemia Cherry Dazzle™ 'GAMAD (Crapemyrtle)

Check out your local Independant Nursery / Garden Centers to see this recent introduction from Dr. Michael Dirr's breeding program / University of Georgia. This Crape Myrtle (Lagerstromia) is a dwarf form selected for its vibrant cherry red flower color. It has pretty glossy foliage and better than average resistance to mildew. No research about this cultivar's resistance to japanese beetles, but we can hope since these cute shrubs had no damage at al!

The L. 'Cherry Dazzel' is touted to be perfectly hardy for the lower Midwest. Most Crape Myrtles die back to the ground each winter and then resprout from the roots late the following spring. Plan to do the typical "crape cut" on this selection once a year. Simply trim off dead wood 6" above the soil level once new growth is evident-usually mid / late May! (Crape Myrtles bloom relaibly, whether killed to the ground or not, since they bloom on new growth each year. Once established, expect flowering period to be from July till late August. )

These new arrivals at Rolling Ridge feature a nice compact growth habit. I loved the foliage, even before it flowered. The newest growth is an copper-red maturing to forest green- very pretty! Dr. Dirr is impressed with its burgundy fall color. With such a compact habit and multiple features, this new introduction looks to be an this an easy multi-season accent for large and small landscapes.
Care Factor Rating: 2 ( must be watered regularly till established and requires only one non-selective pruning occasion)

I think these would be great companions with Knock Out
Roses (this would test the japanese beetle question since roses can be hit hard!) and Purple cone flowers. I have seen a nice cherry red yarrow that would be pretty and a rasberry Monarda, but adding any of these would significantly increase the "Care Factor " rating.

Watch for details on borers that affect Ash Trees and leaf spot issues with Showy Primrose in upcoming blog entries!