This week... Micro Irrigation (Drip)

The two main types of drip we'll discuss here are single emitters and inline systems. Neither is a 100% solution for all landscapes so let's discuss their attributes and uses.

Single emitters. These come in a range of models from � gallon per hour to 2+ gallons per hour. They are a small item that plugs straight into the feeder line itself or via a �" connector pipe. Many moons ago the emitters would clog up with gunk coming down the line or from insects poking stuff (including themselves) down into the orifice. I still have visions of my father in 100 degree heat on his hands on knees poking a paperclip into the emitter trying (with the help of a few choice adjectives) to clear the blockage. Fortunately, the product manufacturers have worked this glitch out and now most are fool proof. This type of emitter works best when plantings are sparse and for new plantings. One emitter is fine for 4" or gallon plants while two are preferred for 5 gallons. The down side is that these little emitters can be time consuming to plug in.

Inline systems. This type of system utilizes a �" pipe with emitters attached to the inside of the pipe at equal intervals i.e. 12", 18" or 24". The pipe was developed for row crops but is useful in gardens also. The benefit of this pipe is that it is a breeze to install. The emitters are built in so all you need to do is connect the pipe to the (pressure reduced) valve then roll the tube out around the plants. Throw a clamp on the end and that's it.

Although this sounds like the perfect solution it does have its draw backs. Firstly, the system is only efficient for dense plantings such as meadows or perennial beds. Using it in a sparsely planted area leaves emitters in no man's land irrigation nothing the first season and a new crop of weeds the next. The second problem is that plants need to be roughly in line and spaced roughly about the same distance apart as the emitters. Otherwise you are trying to bend the pipe to fit the plants which tends to lead to kinks... and more than a little tantrum throwing!

There are two main manufacturers of inline drip and their strengths and weaknesses are as different as their prices. The lesser priced model is available at most big box stores and is about half the price of its competitor. If you only plan to irrigate a small area than this model may work just fine. The higher priced model comes with a number of benefits and naturally a higher price tag. Firstly, it was designed to be used underground (see note below) and is impervious to roots and bugs. Secondly, the emitters are pressure compensated. This means that the emitter closest to the valve puts out the same amount of water as the emitter 200' from the valve. This makes it a lot easier to regulate water.