Drip vs. Overhead for Watering Vegetables

Overhead Systems

• Overhead sprinkler systems are constructed from a range of sprinkler head types and irrigation methods. Some oscillating sprinklers attach to a garden hose and can be moved form one garden area to another. Simple watering cans are also a form of overhead watering as are more complex pop-up sprinkler heads that emerge at preset times. Pop-up sprinklers are connected to underground pipes that are attached to the home's water source. Water small container vegetable gardens with simple overhead sprinkler cans. Medium sized gardens are suited for garden-hose watering or overhead sprinkler systems. Large gardens benefit from pop-up sprinklers, as these provide greater coverage areas.

Drip Systems

• Drip systems also range from the simple to the complex. Soaker hoses are the simplest of drip systems. Attach a porous hose to an outdoor faucet. Place the hose at the base of crops and turn on the water. Water leaks from the porous hose directly above root systems. These systems slowly irrigate crops and are often used for deep watering. Move the hoses from area to area in the same manner as you would a sprinkler. Complex drip systems are made of tubing fitted with drip emitters. Drip irrigation systems conserve water by applying exact amounts of moisture to specific areas. Emitters are directed to plants that require moisture and can emit emit low or high flows as needed, with further adjustments. Because emitters and soaker hoses water the base of plants, less water is lost through evaporation.

Garden Size and Terrain

• Drip watering systems are useful in small gardens with flat terrain. Drip systems rely on water pressure to move water through their hose system. Pressure isn't great enough to move water uphill or over large distances. Overhead watering systems are more effective for areas with slopes and for large gardens, Before installing drip irrigation, ensure that your soil is well-draining. Compacted soils hold water. Standing water damages root systems and crops.
  Overhead sprinkler systems lose water through evaporation and the spray can be misdirected by wind. Overhead watering systems can also cause foliar damage and an increase in risk for diseases like powdery mildew. Use overhead sprinkler systems for large gardens with compacted or clay soils. Water in the morning to lessen the risk of foliar damage.

Crops

• Vegetables require 1/4 inch water per day. When weather is hot and windy more irrigation is necessary. Every day watering isn't necessary, but when the soil is dry to a depth of 4 to 6 inches, then watering is a necessity. Drip irrigation provides slow, deep irrigation and works well with root crops. Large crops like corn or beans are suited for drip irrigation as well. Watering at the base ensures uniform watering. Shallow rooted plants like lettuce and spinach do well with overhead watering but foliage may be damaged if watered at night.