JUNE
Gardeners always like to talk about the weather, but they have had a lot to talk about this year. With only five months gone this year we have dealt with drought, monsoons, hail, high winds, late freezes, snow in April and 96 degrees in May. I think we had three days of springlike weather.
In spite of the weather, our gardens have looked pretty spectacular. Roses have never been so pretty or peonies so loaded with blooms. We have good fruit set on blueberries and blackberries; and tomato plants are coming on strong. So continue to talk about the weather: It means you are paying attention to it and can water accordingly.
• Many of our spring-blooming shrubs flowered later than normal, but since heat has already set in, try to get any pruning chores that are needed done as soon as possible. Once it becomes hot and dry, growth slows. We want them to rebound so they can set plenty of flower buds for next year.
• If they were not winter damaged, big leaf hydrangeas, oak leaf hydrangeas and gardenias are beginning to bloom. These are three plants that bloom in the summer but set flower buds in the fall. The plants need pruning, so as soon as the flowers fade, prune. The single-flowered gardenias ("Daisy" and "Kleim's Hardy") tend to bloom all at once and are done quickly. They can be pruned as needed once all the flowers fade. Many of the newer gardenias do re-bloom later in the season; depending on how much you prune, those later blooms could be delayed or nonexistent. For big leaf hydrangeas and oak leaf hydrangeas that need to be pruned, remove older, thicker canes at the soil line after the blooms have faded.
• Most cool-season vegetables are beginning to bolt or will stop producing as the heat increases. Bolting is the term used for the flower stalk that appears on lettuce, greens and onions. As cool-season vegetables play out, replant with warm-season crops. Now is a great time to begin planting winter squash, pumpkins and gourds, along with okra and Southern peas. You can also still plant tomatoes, peppers, eggplants and watermelons.
• Pay attention to your gardens and monitor for insects and diseases. If you find something you are unsure of, take a good picture and send it to your county Cooperative Extension Service agent, or take a sample in. Early detection coupled with proper identification of a problem, can lead to a fast solution.
• Fertilize tomato plants lightly about every two weeks once they start setting fruit, and make sure you water them evenly. Fluctuations in moisture cause quite a few problems, including blossom-end rot. We typically get our first calls about blossom-end rot when a dry spell is followed by a heavy downpour. Blossom-end rot starts as a water-soaked spot on the bottom of the tomato, which quickly turns black. Most gardeners think they have a disease, but it is a physiological problem, a calcium deficiency typically caused by fluctuations in moisture levels. Mulch your plants, and try to keep the moisture levels even.
• Perennial plants are those that come back for at least two seasons. Right now, many are in full bloom, including purple coneflower, daylilies, gaillardia, hardy hibiscus and lilies. One that continues to gain in popularity is the milkweed. The showiest of the milkweeds is the bright orange butterfly weed, but all members of the Asclepias genus are great host plants for the monarch butterfly.
• As flowers end on many perennials, they begin to form a seed pod. Allowing these plants to set seeds delays more flowers. Deadheading, or removing the spent flowers, will direct energy back into flower production.
• Know the fertilizer needs of your perennials. Some, such as hosta, like regular doses of fertilizer, while others require very little, such as Artemisia and lambs ear.
• Annual and tropical color choices abound at nurseries and garden centers. No garden should be without color, so if yours is drab, start planting. Most annuals and tropical flowers like fertility. Frequent watering also leaches out nutrition, so fertilize every two to three weeks to keep them flowering. As with vegetables and shrubs, monitor your flowers weekly to scout for insects or diseases.
PLANT OF THE MONTH
Periwinkle or annual vinca (Catharanthus roseus) is a tough and durable annual flower for the garden.
It is native to Madagascar, and another common name has been Madagascar periwinkle.
This annual was once the staple in commercial landscapes -- until sprinkler systems became the norm. With frequent overhead watering, the plants developed a disease called stem canker, which killed a lot of plants, and they fell out of favor.
Through advances in plant breeding, we have varieties with good disease resistance to stem canker, and the plant is once again becoming a staple in home landscapes.
Periwinkle plants can be upright in growth habit or spreading. Flower colors vary from shades of pink, red and purple to white, with some interesting bi-color combinations coming soon. Some have a bright center eye, while others are a solid color.
The foliage is a bright glossy green with white veins.
The plants perform best in well drained soils with full sun. Water to get them established, but once they are, they rank among the most drought-tolerant annuals we grow.
Foliage will curl if they begin to get too dry, which is a good sign to water.
They need only moderate amounts of fertilizer.
The flowers do not need deadheading as they will drop as they fade. The plants are covered in blooms all summer.
An added bonus: The plant is poisonous, so the deer and rabbits leave it alone.
Some excellent series to try include: "Cora" and "Cora Cascade" (an upright and a spreading form). These come in a wide range of colors from pure white to blush, shades of pink and lavender with single and bi-color options. The "Cooler" and "Titan" series are also disease resistant.
Coming soon are some outstanding color choices in the "Tattoo" series. Unfortunately these are not disease resistant, but they still would be good choices for containers.
Janet B. Carson is a horticulture specialist for the University of Arkansas Cooperative Extension Service.
HomeStyle on 06/02/2018