We were blessed with a wonderful rain shower on Monday afternoon, and my gardener’s spirit is revived! It is disheartening to watch the vegetable and flower crops you carefully nurtured succumb to extreme heat and drought. I am grateful!
I noticed that the slugs have arrived. I was hoping that the dry weather would have curtailed their appearance, but the damaged leaves on some of my hosts are evidence of their chewing activity. Slug bait pellets are very effective if you apply the product before the beauty of the leaves is destroyed.
I recommend spraying roses with a fungicide to prevent black spot which will be showing up soon at this point in the season. Several chemicals are effective in preventing this disease, which is easy to prevent but hard to control. Applying spray to both upper and lower leaf surfaces is important.
Several perennials have finished their first bloom cycle. Cutting off the old flower heads will encourage a second round of flowers later in the summer. When cutting off the flower heads of roses, make the cut just above a five-leaflet leaf. The first leaves under the flower are usually three-leaflet leaves, and cutting at that point will most often result in a stem of leaves rather than flower buds. Cut back far enough to keep the bush shaped.
This is also the right time to apply an insecticide to vining plants like pumpkins and squash that are susceptible to squash vine borer. Apply the spray at the base of the stem just above ground level. That is where the adult lays eggs and the resulting larvae bore into the stem. The damage you will notice first is wilted leaves, at which point you have pretty much lost the battle. In a couple of weeks, the entire plant will collapse due to the feeding activity of the borer inside the vine.