If your don't rely on an automatic irrigation system you probably watch the weather closely and are concerned about when to water your landscape plants. There are some various factors to consider, but a simple approach for starters, is to give your flowers and shrubs supplemental water any week that there is less than one inch of natural rainfall.
Today is Wednesday June 5 and we've already had close to half an inch in Nashville this morning. By Thursday afternoon I would estimate at least 1.5 inches (based on NOAA projections). So all things being equal, you might not think about watering again until middle of next week.
Since all things aren't equal, remember that some plants like a little less water, some a little more, some locations in your soil and yard hold moisture longer. Most plants do not like 'wet feet' where the soil stays moist and soggy for days at a time. This can lead to water starvation and fungal diseases. Prevent these problems by watering deeply but infrequently (e.g., not daily!) and by amending your garden soil with natural materials like finely shredded pine bark, known as 'pine fines' or with compost you have made or bought. This helps the soil drain better.
If you have shrubs that have been growing successfully in place for several years, they may only need extra watering in times of drought.
Particurlarly, these shrubs and flowers are very tolerant of dry periods:
Nandina
Yew
Oak Leaf Hydrangea
most native shrubs ( Fothergilla, Itea, Ninebark, native Viburnums, Hearts A Bustin, etc)
Sedums, Coneflowers,Salvas, Columbine, Asters, Joe-Pye Weed, Sunflowers,Bee Balm, Lavendar, Lenten Rose and most understory wildflowers are drought tolerant and can rely only on natural rainfall.
