Garden Talk: June 2, 2014
From NGA Editors
Picking Perfect Phlox
Garden phlox is one of the stalwarts of the summer garden, providing color and stature during the midsummer months. But, although lovely, it isn't always carefree. Too often powdery mildew mars its leaves during warm, humid weather and spider mites leave leaves yellowing and misshapen. Fortunately, breeders have been working to overcome these problems and varieties are now available that show good resistance to these threats.
To help gardeners choose the best from among the many garden phlox cultivars on offer, from 2001 through 2009 the Chicago Botanic Garden conducted an evaluation of 78 different kinds of phlox, including cultivars of Phlox paniculata, P. x arendsii, as well as some hybrids. All plants were grown in full sun at the Botanic Garden located in USDA Hardiness Zone 5b and AHS Heat Zone 5. Plant were given minimal maintenance, receiving mulch and overhead watering as needed, but no fertilization, pest or disease control, or winter protection. Plants were evaluated for bloom period, flower coverage, mildew resistance, and degree of mite infestation and given an overall rating of one to five stars.
Only one cultivar rated top honors. Rosy pink Phlox paniculata 'Shortwood' took the prize for its exceptional performance and floral display coupled with excellent powdery mildew and spider mite resistance. Fortunately 27 other cultivars received high 4-star ratings, so there are plenty of good choices that offer a wide range of colors and heights.
To read the entire comparative study of garden phlox cultivars and see all the cultivar ratings, go to Chicago Botanic Garden.
'Patio Baby' Eggplant
Eggplants in the garden are beautiful to look at and offer lots of delicious culinary possibilities in the kitchen. But they are not always the easiest crop to grow. It can be a challenge to mature a crop in parts of the country that don't provide long, hot summers. That's why gardeners in short-season areas will welcome Patio Baby, a new compact eggplant variety that is both very early, with a days to harvest of just 45 days from transplanting, and highly productive.
In recognition of its merits, Patio Baby was named a 2014 All-America Selections Regional Vegetable Award winner for the Northeast. All-America Selections are reliable new varieties that have proven their superior garden performance in trials evaluated by impartial expert judges.
Growing only 16-20 inches tall, Patio Baby is also a great choice for container growing. Its deep purple, egg-shaped fruits should be harvested at 2-3 inch long baby size and are delicious roasted or in dips and salads. Thornless leaves and calyxes allow for painless harvesting. Plants will continue to produce fruits the entire season. As with all eggplants, wait until the weather is warm and settled before planting outside, with night temperatures reliably above 60 degrees F, and give plants regular water and fertilization for the best performance.
To find out more about Patio Baby Eggplant, go to All-America Selections. (Image courtesy of All-America Selections)
You Glow Girl!
To get the most from your landscape plants, keep in mind what they offer as the seasons change. A flowering shrub may look gorgeous in full bloom, but what does it offer when it's not in flower? For the biggest impact from your plants, try to include as many with multi-season interest as you can.
One such plant that offers a changing show from spring to fall is the new Glow Girl® Birchleaf Spirea (Spiraea 'Tor Gold') from Proven Winners. New leaves emerge tinged with copper in spring, changing to a bright lime green; then buds with hints of red open to clusters of white flowers. Summer foliage is a sunny yellow that holds its color well and doesn't burn. Finally, in fall the leaves turn to shades of rosy red. This compact shrub gets 3-4 feet tall and wide, making it easy to use in many landscape settings. Adapted to zones 3-9, it does well in full sun or part shade and isn't fussy about soil. Prune right after flowering, as it blooms on old wood.
To find out more about Glow Girl® Birchleaf spirea, go to Proven Winners. (Image courtesy of Proven Winners)
Non-Invasive Butterfly Bushes
Butterfly bushes (Buddleia davidii) are long time garden favorites, both for their graceful, fragrant panicles of flowers, as well as for the butterflies these blooms draw to the garden. Unfortunately, there is a dark side to these shrubs. They naturalize and spread with abandon and have become an invasive threat in many parts of the country, crowding out native vegetation in a variety of habitats. Planting butterfly bush is strongly discouraged in many states, and had been banned in Oregon, under its noxious weed quarantine.
However, the Oregon Department of Agriculture (ODA) has approved the sale of certain sterile butterfly bush cultivars that have been evaluated through field studies as producing less than 2 percent viable seeds and that do not pose an invasive threat. Currently the cultivars Asian Moon, Blue Chip, Chip Jr., Ice Chip (formerly White Icing), Inspired Pink, Pink Micro Chip (pictured), and Purple Haze have been approved as demonstrated sterile plants. Also on the list are the Flutterby Grande™ series cultivars Blueberry Cobbler Nectar Bush, Peach Cobbler Nectar Bush, Sweet Marmalade Nectar Bush, Tangerine Dream Nectar Bush, Vanilla Nectar Bush; Flutterby Petite™ Snow White Nectar Bush; and Flutterby™ Pink Nectar Bush. Three interspecific hybrids have also been approved for planting; the fertility of these cultivars has not been assessed, though interspecific hybrids generally exhibit low fertility. They are the cultivars Lilac Chip, Miss Molly, and Miss Ruby. No matter where you live, these Buddleia varieties will let you enjoy butterfly bush in your garden without damaging the wider environment.
For more about ODA's butterfly bush cultivar approval process, go to ODA. (Image courtesy of Proven Winners)