2015 Bugaboos

There are some issues of interest for homeowners and landscape lovers this year.

Roses, crape myrtles, Impatiens, and walnut trees are the hosts to some pesky pests.

Rose Rosette Disease is not new but we are continuing to see much impact. The summary version is this: a probable virus, spread by a mite, for which there are not currently controls, may affect any variety and species of rose, after which it will decline and die. Signs include excessive thorniness especially internodal thorns, deformed red cluster of foliage and buds, plant die back. This is not spread through poor hygiene or handling, only through the insect vector. More information at this link:
https://docs.google.com/document/d/19O6j-kO_bkmXPo75j3pN3dOFxaWtT9Mp9nqJoF-_6sU/edit

Impatiens downy mildew and Impatiens Necrotics Spot Virus is affecting bedding plants in over 30 states in the U.S.  A IPM approach (Integrated Pest Management) calls for rotating crops in planting beds, and nursery-level control.  

Plants which appear not to be affected are New Guinea Impatiens, SunPatiens, as well as other species for shade like annual and hardy Begonia. And shade perennials.

Crape Myrtle Bark Scale is appearing in west Tennessee. Scale is an insect. Its feeding patterns may stress crape myrtles and reduce flowering. Of course there are other reasons for shrubs to be non-performing and if you have a concern, look at the big picture including siting, soil/shade needs, soil testing and nutrition, the possibility of environmental or mechanical stresses. 

Here is an article from the University of Arkansas.

http://www.uaex.edu/publications/PDF/fsa-7086.pdf

Walnut trees and Thousand Cankers Disease

http://eppserver.ag.utk.edu/EPP-alerts/alert-walnutBeetle.html

http://www.tn.gov/agriculture/regulatory/tcdfaq.shtml

Early Fall on the Cumberland Plateu

Here are a few beauties from the Fiery Gizzard trail, near Foster Falls in Grundy County Tennessee.

 I think this is Callicarpa americana, the native Beautyberry.

 Some pretty colors and mushroom.

 Field flowers above the falls.

More plants that are sort of not-plants.

 The Fiery Gizzard trail, along the southeastern end, is littered with the huge paper like leaves of the native deciduous Magnolia. There are many mushrooms emerging and rhododendrons covering the hillsides. Asters are blooming as well. Fall yields up an abundance of beauty in Tennessee woodlands.

Heat Lovers

For the hot summer days, we get rewarded with a host of beautiful blooms including these:


Ascelpias Tuberosa, Butterfly Weed.

Echinacea 'Sombrero', hosting a black butterfly.

Tickseed (Coreopsis) "Route 66", a lover of heat and sun.

Bear's Breeches (Acanthus mollis) likes partial sun, and I think prefers a slightly alkaline soil and decent drainage.

Echinacea, as most of us know by now, includes the native Echinaceas  purpurea and tennesseensis - the purple coneflowers, and slew of cultivars of crazy bright colors in the white/yellow/orange/red ranges. They grow in full hot sun, don't want extra water, and have not too many problems. The natives grow about 3 feet tall, the cultivars come in all sizes.

Butterfly Weed, part of the milkweed genus, is both a wild and cultivated sun-lover. Best in full-sun, not excess water. It grows about 18 inches high and blooms mid/late summer with a bright orange clusters. It doesnt transplant well but I have saved the seed and started plants.  Be patient in the spring as it really waits for very warm weather before emerging from the ground. I leave a marker at its home spot in my garden so I know where it will be each year. There are cultivars to be obtained as well, but I like the native so much, it's all I want.

Coreopsis is a great sun-lover that is pretty easy care. It doesn't need a lot of water,and blooms most of the summer. Sometimes they can get a little floppy, so may need staking or some friends nearby to crowd them into standing up. They are daisy-like blooms with the cultivars available in yellows, reds, whites and oranges. A fantastic starter is "Jethro Tull" with its appealing cupped bright orange petals.

None of these get supplemental watering in my yard, unless we go through a two or three week drought.

Zone Detour: The Tropics

The Cayman Islands, a British overseas colony, are a group of 3 small islands in the western Caribbean. They have a tropical marine climate. I visited Grand Cayman, an island of about 100 square miles. I was able to visit a private garden, observe naturalized plantings and visit the Queen Elizabeth II Botanic Park, which not only has lovely flora on display but is home to a breeding and conservation effort for the native Cayman Blue Iguana - endangered and found only on the island of Grand Cayman.
 The creature is in fact blue, or brownish and blue depending on how long it may have been sitting in the sun; as it warms up, more of the blue colors emerge. The largest one we saw was about 2 1/2 feet long.
I do not have identifying information for many of the plants pictured here...my knowledge of tropical plants is very limited, and at the QEII park, there was only partial tagging. Beautiful none the less.

First, photos from the QEII Botanical Park (all photos, credit: Louise Zepp):

Zone Detour: The Tropics, part 2

Second part of my visit to Grand Cayman. I did visit much of the island, including Georgetown, West Bay, BoddenTown/East End.

A legume, with caterpillar, growing near a beach.

Orchid, growing on tree trunk, in private garden.

Cactus, in private garden. There were also plums, lantana, palms, vinca, and something that looked like Secreseia/Tradescantia in this garden.

Palm, at Spotts Public Beach.

Another orchid growing on a tree trunk, private garden.

Just Because It's Summer

Some lovely blooms of summer:
Hydrangea quercifolia, a dwarf variety, a close-up of the bloom, and en masse. Then a 'Vision in Pink' Astilbe. And 'Endless Summer' Hydrangea macrophylla.
 By the way, the Hydrangea quercifolia (Oak Leaf Hydrangea) tolerates quite a bit of dry weather. Astilbes, on the other hand, really want some regular moistur

"They're Here!"

Who remembers Drew Barrymore's character in Poltergeist announcing the arrival of the....whatever they are....

Well, Rose Sawflies are back, for their annual spring appearance. These individuals were found in a garden in Green Hills area of Nashville on Friday.

They are just hatching and beginning their big feast on rose leaves. They can munch up a lot of rose leaves within the few short weeks that they are feeding. Then they drop to the ground and enter their pupa stage, and are harmless to the rose. Often the damage isn't noted until it's severe or after the sawfly larva are gone. 

Inspect your roses now. Look on the underside of the leaf for the pale green creature that looks like a caterpillar. Control it by: spraying with a hard stream of hose water. Organic pesticides include Neem and permethrins. Bt is not effective. 

Don't apply pesticides if there are no pests present.

Most healthy rose plants will survive unless completely defoliated. You can prune off the affected leaves and of course shrub roses, like Knockout roses, will probably bounce back and bloom on the new growth.

Here's a great link with a longer discussion of sawflies and Integrated Pest Management

http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/insects/sawflies/rose-and-pear-slugs-sawflies.aspx

Photographs © 2014 Mary Boyd