Welcome to the Garden

Notes from the Garden - August, September, October 2014

by Harvey Cotten

While the heat and humidity of the summer is still with us, we know that the prospect of shorter days, cooler nights and the change of the seasons is just around the corner. One can almost smell the hint of fall in the air and long for the cool days that will be here before we know it as we sweat through August and the heat that can stifle even the staunchest gardener.
While it can also be said that our garden plants are yearning for the cooler days of fall just as we are, we know that many shine in the heat of late summer. Come out and enjoy the last that summer has to offer and the promise of cool days and color changes that lie ahead.

August: Hydrangea paniculata
The Garden is full of many hydrangea selections, most of which bloom in late spring to early summer. However, the cultivars of Hydrangea paniculata (the Panicle hydrangea) are the last to bloom and are still in all their glory during the hot, humid month of August. Beginning in mid-July, these hydrangeas create a beautiful floral display of pure white flowers changing to varying shades of rosy pink to cream. When I was first learning about gardening, I loved seeing Pee Gee hydrangea blooming in late summer. At that time the cultivar (H. paniculata ‘Grandiflora’) was the only selection of H. paniculata sold in the garden centers. It was a good plant with beautiful double white flowers, but one drawback was its size in the landscape, as it grew big and made it hard to find a large enough space to let it grow and thrive. In the late 1990’s, Dr. Michael Dirr of the University of Georgia began breeding hydrangeas. One area he centered on was looking at more selections of H. paniculata for home gardeners. The dwarf selection ‘Chantilly Lace’ came out of this effort and we were excited about planting it when we built the Children’s Garden and Nature Center. Proven Winners has been active in releasing new cultivars including ‘Limelight’ and ‘Little Lime.’ I also like ‘Little Lamb,’ ‘Silver Dollar’ and ‘Phantom.’ ‘Phantom’ has shown great heat tolerance and has been grown successfully as far south as the Gulf Coast. H. paniculata selections make great cut flowers and can also be dried for more permanent arrangements. Come out and walk through the Garden to see the different selections of H. paniculata that are included in our Hydrangea collection.

September: Panicum virgatum
I truly love ornamental grasses as landscape plants and have been excited about their acceptance by garden designers as suitable, garden-worthy choices. One of the best native grasses that we have at our disposal is Switch grass (Panicum virgatum). Switch grass has a wide native range, growing over most of the eastern and mid-western states. It has gained a strong following in the research area as a potential crop for biofuels in that it is a native grass, comes back each year, has low fertility requirements, is drought tolerant and grows over a wide range of soils. This would be a more preferable choice than corn for making biofuels; hopefully, the research will prove productive in that area. As an ornamental plant, Switch grass is a great choice for our gardens. Easy to grow with no pest or disease issues, it only needs to be pruned once a year. The foliage is bright green, turning a straw tan in winter. The species grows about three feet tall, but the cultivar ‘Cloud Nine’ can reach over eight feet in height. My favorite selection is ‘Northwind,’ an upright form growing five to six feet in height. This cultivar was designated the Perennial Plant of the Year for 2014 by the Perennial Plant Association. This award shows the versatility of this plant, since it is given to one that grows over much of the country, is easily propagated and has few pest or disease problems. Another selection I like is ‘Shenandoah’ with colorful streaks of red and purple in the foliage. It makes a great container plant as well as in the landscape.

October: Solidago rugosa 
Goldenrod is a plant in need of a good ...