The brightest of the stars in the Big Dog constellation is Sirius, the Dog Star. In the mid-summer, it can be seen rising and setting with the sun. This conjunction caused the ancients to believe that Sirius’ heat added to the heat of the sun, creating a stretch of hot and sultry weather. They named this stretch of time, from 20 days before the conjunction to 20 days after, the Dog Days, which this year, begin on July 3rd and run through August 11th.
All of the heat we’ve experienced in the last few days combined with the relatively dry weather so far may mean that plants struggle to establish this summer. July traditionally ushers in drier conditions. Don’t forget to check your soil for moisture and water your plants! Summer rainstorms are notoriously fickle and if we get another period of dry weather, any tree or shrub planted in the last two years will need its roots soaked once a week. Perennial and annual borders will benefit from watering as well. If dry weather continues, it’s also a good idea to root-water even established trees and shrubs, especially Beech, Japanese Maples and Redbuds. Drought stress can weaken a plant’s ability to fight off disease and pests, and may affect winter hardiness.
June was Perennial Gardening Month, but July has its own charm. If your garden is looking a little tired, you can add some flower power with Daylilies, Garden Phlox, Liatris and Coneflowers. You can continue to plant perennials all summer as long as you are paying attention to their watering needs. Newly planted flora will need some baby-sitting if the temperatures start to soar. So if your personal gardening energy is still in planting mode, go ahead and add some new colors and textures.
Shear perennials after their first flush of blooms to encourage a second flowering. Coreopsis, Veronica and Salvias all respond beautifully to this haircut method of pruning. You don’t have to prune stem by stem. Grab a handful of stems and cut the whole bunch at once. They will grow out and look natural in a few weeks. And for those perennials that re-seed a bit too vigorously, this is a must-do gardening chore, unless you relish weeding out unwanted seedlings later this summer or next spring.
While you’re deadheading, shear back your Japanese Spirea and Potentilla that have finished flowering. Continue to dead-head Roses to encourage re-blooming. And it is time to prune Arborvitae, Yews and Junipers now that the new growth is darkening in color. Be prudent though and leave enough of this year’s growth to develop buds for next year.
We haven’t seen samples of Japanese Beetle damage at the Plant Info Desk yet, but we’re sure that they’re on the way to a garden near you! Watch for them on Roses, Hibiscus and other flowering shrubs. When they do arrive, you can pick them off and drop them in a bucket of soapy water. Or try an insecticidal spray, like Eight or Bonide’s Japanese Beetle Killer. These contact sprays work the best if the product actually touches the insects. Insecticidal soap is not effective on beetles, but the JBK is made with pyrethrin, an insecticide derived from chrysanthemum flowers and is considered organic. Captain Jacks Dead Bug is also highly effective, though it’s slower acting than the contact insecticides. Use traps only as a last resort in a remote area of your yard. They will attract as many beetles as they catch. And you’ll have to clean out the trap. Yickers!