Here are a few tips to make sure your plants are safe from the dreaded death from overwatering.

1. After tucking flower bulbs, bare-root perennials and small transplants into soil, water well to settle the dirt. Then walk away and don't look back (for a while).
2. Water indoor bulbs again when green top growth appears. This typically occurs in 1 to 3 weeks, depending on the variety. Some sleepy bulbs/rhizomes, like cannas, can take a long time to begin sprouting.
3. Outdoor perennials and transplants will need water in 3-7 days or when the soil is dry about 1.5 inches down. Poke your finger in to see and don't assume that dryness on the top of the soil translates into a parched environment below.
4. Plants need moisture to replace that which is lost through evaporation from leaf surfaces. No leaves = no evaporation (or next to none.) As plants grow large and develop lush foliage they will lose more moisture through their increasingly numerous leaves. More water will be needed to replace that which is lost.

Other helpful considerations:

1. To thrive, plant roots need to be able to absorb oxygen. This can't occur if the soil is wet and all the space for air between soil particles has been taken up by water.
2. The source of water doesn't matter and either Mother Nature or your sprinkler can provide too much. Be mindful of what's happening in your yard before assuming that more water is needed. Use a rain gauge or even just an empty tuna can to keep track of how much moisture (rain and sprinkler water) is really being received.
3. Different types of plants have different water needs. If you live in an area that gets lots of rain and you want to grow dry land varieties, consider potting them up and placing them where they will be sheltered from most rain storms. Sites that often work include the area under house or garage roof overhangs and on covered porches, assuming the plants' sunlight requirements can be met.
4. Plants in pots without drainage holes must be handled extra carefully as excess water will pool in the bottom of the pot. Water judiciously. 

5. In very hot weather, plants often droop. This is natural and is not necessarily a cry for more water. Watch to see if plants perk up in the cool of the evening.  If so, all is well. Over watering in hot weather is especially dangerous as it more readily leads to rot. 

6. Plants, like kids, are individuals. Even within the same variety, some sprout and grow more quickly than others. For those plants that get off to a leisurely start, water lightly, keeping in mind that there's little, if any, foliage to support.

7. Watering to a depth of 6 inches encourages deeper, healthier root development and it allows longer periods between watering. If only half the water required for healthy garden growth is applied at a given time, it only penetrates the top half of the root zone; the area below remains as dry as if no irrigation has been applied at all. 

One final thought . . . if you start mornings by watering your pots and gardens and give each an inch of water, you've effectively provided the equivalent of 365" of water per year. That's more than 30 feet of water. No place on earth gets that much rain. So while a few containers, ones in full sun, subjected to consistant winds and with unglazed terra cotta sides may need lots of moisture, most of your garden will be happy with an inch or two a week.