KC Gardens

Plant of the Week: Zinnias

From Dennis Patton:

Annual flowers have come and gone over the years but one favorite that has stood the test of time is the good ole zinnia. I have fond memories of planting various seeds as a child, and watching them sprout and mature into a beautiful bush. I remember cutting the stems and entering them in the local county fair. Sometimes they were winners, while other times they left a little to be desired.

All these many years later, zinnias still find their way into my garden just about every year. Zinnias will take the KC area heat and thrive. Really the only issue with zinnias is a foliar disease, powdery mildew. This mildew will first turn the foliage grayish white and cause it to shrivel, leaving a less than desirable looking plant.

Thanks to modern breeding several varieties have been developed that are less susceptible to mildew. Many of these varieties have been tested right here in western Olathe as part of Kansas State University’s Research and Extension Prairie Star trials. These varieties are big on color and have clean foliage. Based on this research I only plant these varieties. Some can be found locally as transplants while others may need to be ordered as seeds.

Let me add another comment about varieties. There are larger flowering (what I call old fashioned) zinnias, and the newer more compact types. For the purposes of this column I would like to focus on the big flower, or old-fashioned types. I will name-drop a few others at the end.

Benary’s Giant has to be at the top of everyone’s planting list. This plant grows to almost 3 feet and has large showy flowers on long stems great for cutting. Benary’s come in a wide range of colors. Take a trip out to the Overland Park Arboretum and Botanical Garden and you will see this variety putting on a show in the Monet Garden.

Oklahoma Series is another tall plant but the difference here is the flowers are smaller, maybe the size of a fifty cent piece. They also come in a wide range of colors and create a colorful planting. They are good for cut flowers.

The Queen Series is a blend of green and mauve zinnias which is very striking. It grows on a larger plant and produces loads of wonderful flowers.

A newer introduction that is in my garden this summer is Bridesmaid. This plant is compact reaching only 20 inches tall and wide but is covered in large sunshine yellow flowers. In my garden they have bloomed nonstop since planting. Best of all I rarely deadhead and they just keep on coming with nice clean green foliage.

Now for a few of the smaller types: The forerunner for the group was the Profusion Orange and White. Then along came the Zahra series in orange, yellow, cherry and coral. These bloomed even better. They are all wonderful to grow.

New on the trials for 2014 is a smaller purple zinnia called Uptown Grape. From what I can tell this year it is going to be a hit. It is currently growing in our demonstration garden at the office and has showy blooms in a bright purple held high above the foliage to create a dramatic display.

So no matter what variety or size you like, zinnias, with their new and improved resistance to mildew, should be, in my book, part of your summer planting plan. I know I just have to smile when I see a zinnia basking in a Kansas City summer.