Landscapes flower and vegetable beds sure needed some moisture; just getting it all at once is not ideal. Couple the high humidity, temperatures together, and we have great opportunities for disease outbreaks in the yard.
Some general precautions would be NOT to work in the beds at all while the foliage remains wet. As gardeners, we can spread disease pathogens on our pants, gloves and garden tools. The typical fungal disease needs what is called the disease triangle in order to infect our plants. The three parts are having the pathogen present, a susceptible host and the right environmental conditions. The one part of the disease triangle that is usually missing is the environment. Currently that has not been the case with all the free moisture on plant tissue and in the air. A couple of easy examples of disease just waiting for the right conditions in the home landscape are powdery mildew and rust. Both appear in the lawn right now. Powdery mildew can also been seen on several perennials and shrubs. In the vegetable garden, powdery mildew can be seen on many of the vine crops.
In the vegetable garden, tomato foliage diseases that have been slowly growing can really take a hold now. The pathogens start at the soil line having been splashed up from the soil and begin to infect the inner lower leaves, the ones we rarely pay attention to. The recent heavy rains clearly sent soil flying all over the lower leaves for sure and more likely several more inches upward. Strong sunlight and good winds will dry out the leaves and lessen the infection period.
Disease management in the home landscape and gardens can be difficult since gardeners grow so many different kinds of plants. There is no universal treatment available and treatment timing will vary species to species. In the vegetable garden, grow disease resistant plants if you can. The heritage/heirloom varieties have very little if any disease resistance and gardens rely heavily on rotation, management strategies such as mulching to keep the plants clean. Spacing is very important to create good air movement among the and within the plants. If you can eliminate the environment that allows disease to develop, you are way ahead of the game.
While not a disease management issue, rain does cause another problem for tomatoes. Any tomato fruit that is already mature or nearly so can split open during a rainy period. The tomato skin stops growing once the fruit is mature. Rains allow the plant to continue to absorb water out of the soil and that moisture will be moved into the fruits. The result is the skin splits. To avoid this, harvest any tomato fruits that are mature or ripe or in your estimation will be ripe in the next few days. Fruits that are green or just starting to turn color can still absorb the moisture without splitting.
Gardeners may see a slightly different situation with our vine crops, especially cucumber. The cucumber fruit will grow very rapidly and develops in response to available soil moisture. Cucumbers will appear thin in some spots and fat in others. To keep a uniform shape and size, moisture control is key.