Independence Day! 4th of July! Summer colors lean to red, white, and blue. A basic staple in red and white for the American summer garden is the sun-loving geranium. Because of their pretty blooms in many colors, lovely fragrances, and culinary uses, scented geraniums are a wonderful addition to herb gardens, borders, window boxes, and hanging baskets. Some can even be used as ground cover. Geraniums are known for their aromatic, green foliage, the fragrance of which varies from plant to plant.
The true geranium is a perennial geranium plant, which is a cold climate plant. What we call a geranium originated in South Africa and was brought to Europe in the 18th century by Dutch traders. These annual flowers actually belong to the Pelargonium family and are not true geraniums, but resemble the geranium.
While there are several types of Pelargoniums, the two most popular are the Zonal Geranium and the Ivy Geranium. The Zonal geranium (Pelargonium x hortorum) has several distinctive features. The name is derived from the circular zone of red, bluish or purple colored striping through the middle of the round, almost kidney shaped leaves. The flowers on zonal geraniums resemble spheres that stand atop sturdy stems. The many colors of today’s modern hybrids bloom in nearly all the colors of the rainbow, especially pink, lavender, yellow, peach, orange, rose, white, and of course the classic red. If you want a geranium hanging basket, look for an Ivy Geranium (Pelargonium peltatum). This geranium naturally grows in a cascading form which is perfect for a hanging basket or window box. It is named for its glossy green, ivy-shaped leaves.
When you cross a zonal geranium with an ivy geranium, the result is an interspecific hybrid geranium. It is the best of both worlds in one plant with big, nonstop flowers on a plant with a mounding or slightly trailing growth pattern. These crosses have a great heat tolerance and fill planting beds and containers with lots of color all season long. Look for the Calliope or Calliente varieties.
Whether you’re growing annual zonal geraniums, ivy geraniums, interspecific hybrid, or old-fashioned scented geraniums, many aspects of geranium care remain the same. Geraniums crave sunshine. Six to eight hours of full sun each day works well, but in the hottest part of the summer, a little shade during the afternoon will keep your plant blooming. Geraniums have a tendency to stop flowering during especially hot weather. A full day is great but plants will thrive best with shade during the hottest part of the day. Ivy geraniums need light shade in all regions, especially as summer temperatures soar.
Geraniums are great drought-tolerant plants, so be careful not to overwater them. Wait until the top one inch of soil is dry. If the geranium is in a pot, be sure to have plenty of drainage holes in the bottom. Geraniums are heavy feeders, so be sure to plant them in soil with a slow releasing fertilizer. Add a water soluble fertilizer after about four weeks and then about every twenty days. Geraniums bloom best if they are kept somewhat root—bound. Repot your geraniums into larger containers only when necessary and then use a container that is just one size larger. To keep those blooms coming, deadhead the wilted and faded flowers. This will encourage new blooms to shoot up. Snap the stems as close to the main plant as possible.
With a little food and water, lots of sun, and some occasional attention, your colorful geraniums will thrive all summer long.