How much water your plants need to stay healthy depends on several factors:

• Climate and weather: The average weather where you live on a season-to-season, year-to-year basis determines climate. Out-of-the ordinary weather can wreak havoc on your plants. Hot, dry winds can fry plants even when the soil is moist.

• Soil types: Sandy soil holds water about as effectively as a sieve, while the dense particles in clay cause the soil to crust over and deflect water drops. In both cases, adding organic matter helps alleviate the problems.

• Location: In general, shady gardens need less water than those receiving direct sun. However, in places where trees cast shadows, their roots may greedily hog all the water, leaving little for the flowers.

• Genetic disposition: Most plants need a consistent supply of moisture to remain healthy and free-blooming. Some types, however, can get by on less water than others.

Getting Water To Your Garden

The best watering method often depends on how large your space is. In some areas, certain watering techniques become a matter of necessity instead of practicality. Where droughts are common or water supplies are unpredictable, conservation is the order of the day. And, where foliage diseases, such as powdery mildew are common, you want to keep water off the plant leaves and apply the water only to the roots. The following list describes several watering methods:

• Hand watering: Hose-end attachments soften the force of the spray and help apply the water over a larger area. You can control the amount of water each plant gets and even do some pest control at the same time — blast that blanket flower to wash away aphids!

• Sprinklers: The problem with sprinklers is that you have to drag the hose all around and move the sprinkler every so often, most hose-end sprinklers don’t apply water very evenly, and you waste water if you forget to turn off the sprinkler.

• Furrow irrigation: Furrows are shallow trenches that run parallel to your rows. You typically dig the furrows with a hoe at planting time and then plant a row of flowers or vegetables on either side of the furrow. Ideally, the bed should slope just the tiniest bit so that water runs naturally from one end of the furrow to the other. (See image below.) When you want to water, you just put a slowly running hose at the end of the furrow and wait for the water to reach the other end. Furrow irrigation keeps the foliage dry and doesn’t promote disease, but you still have to move the hose around frequently, and it doesn’t work well on fast-draining, sandy soil.

  
  A garden bed showing furrow irrigation where water flows between rows of plants.

• Drip irrigation: Water slowly drips through tiny holes, or emitters, in black plastic pipe. The pipe connects to a water supply, filter, and, often, a pressure regulator. The pipes weave through the plants, applying water directly to the base of the plants. You can lay the pipe right on top of the soil and cover it with a mulch or bury it a few inches deep. Drip systems usually have to run for at least several hours to wet a large area, so watch the soil carefully the first few times you water. If you live in an area where the soil freezes, prevent your drip system from bursting in winter by draining the water, rolling up the tubing, and storing it in the garage.
  
  Drip emitters can wet an entire planting bed from one end to the other at each watering. (You can either snap the emitters into the pipe or buy the pipes with the emitters already installed.  ....read more