My troubles to date have been the probing nibbles of deer (usually because I don't have the Water Scarecrow sprinklers aimed quite right, or are insufficient in number....they've sampled some young hot pepper plants, and each end of a bean row - but the damage has been minimal), a few chews of foliage by beetles of various sorts, and the seemingly inevitable appearance of disease on tomato plants. Diagnosing disease is tricky and challenging business and is worth some Googling at pictures and perhaps a visit to the local Extension service with some tainted plant parts. Our current conditions - lots of rain, especially late in the day (meaning wet foliage overnight) - seems to be favoring some Early Blight (alternaria), showing up on lower foliage or that at the rear of the plant (brownish spots, especially on the edge, with some yellowing next to it), away from the direct, day long rays of the sun. If the agent is present, the increasing heat and humidity can also bring on Fusarium wilt, which shows itself as wilting (even when the plant is well watered) and then yellowing of the foliage on a particular stem of the plant.
Below are some pictures I took of the issues I am dealing with (and compared to previous years, things are pretty rosy - I am wondering if all of that bleaching, detergent-spraying, of pots, stakes, the driveway, are really helping). I am not spraying, though there is no shortage of products that can be used (again, Google is your friend). What each gardener uses is a very personal choice. I am going around the garden each morning with a container of detergent and shears - I am cutting off the lower impacted foliage and then dipping the shears in the detergent, so I don't spread issues plant to plant. For the deer, I added the second Water Scarecrow to the driveway garden; for the side yard garden, I've got my unused tomato cages providing blockage to the rear of the garden, and aiming the scarecrow right down the middle to protect the garden front. It is a daily - and nightly - battle and I am sure surprises await me in the coming days and weeks!
By the way, we ate the first ripe tomato today - a Mexico Midget - 37 days from transplant...and yummy!