I know it's still hot and hard to believe that the weather will cool down soon but I have been hearing the locust for a couple of weeks now and that means 6 weeks until frost. The other weather condition that is now starting is that at night when the temperatures drop, dew develops by morning and causes mildew and black spot. These are problems that usually go unnoticed during hot, dry conditions. Now is the time to start the fungicide spraying or dusting, especially on your roses and vining vegetables such as melons and squash and pumpkins. Fungicides work best as a "preventative" so don't wait until you see the problem, act now.
My roses have gotten "leafless" even though they still have flowers. They are not pretty so last week I simply cut them all back much the same way you would in the spring. Cutting them back later in the fall, just before they go dormant, is not a good idea therefore I did it now, giving them plenty of time to re-grow and probably even bloom again yet this year. This treatment also helps to give me new, fresh growth that I can treat with fungicides early on and get a handle on the insects and mildew problems.
A lot of folks have been complaining about rotting ends on their tomato fruit. When this happens, it is a sign that your soil is lacking calcium and is in need of lime. You can apply some lime now but it is always best to plan on incorporating the lime into the garden soil after the vegetable plants are removed for the winter. There is a product you can buy for spraying on the fruit early to prevent "blossom-end-rot" but it doesn't fix the calcium deficiency for next year.
Have you seen a lot of butterflies and white "Millers" flying around your plants this year? Well I have news for you...that's just the start of a much bigger problem. When these flying insects fly around your plants they are actually laying eggs that hatch into caterpillars and immediately start eating whatever they can find. For me, it is my 3,000 hardy-garden mums! Well I went immediately to the garden shop to get some Di-pel (the organic worm killer) only to find out that I was out. I did order it though; I must stop these creatures. They also go for cabbage, broccoli, cauliflower and many other garden vegetable plants.
The rule-of-thumb for cutting back perennials is "just after they finish blooming". This year I followed my own advice and cut back our unsold azalea plants back a few weeks ago. They looked terrible at the time and no one wanted to do it but now they look great. In fact someone just purchased 3 of them because they were so healthy; same thing with the lilacs. Later, towards fall, the use of Wilt Pruf and summer dormant oil will be applied to lock in moisture and to kill off those most difficult insects.