This instructable gives an very cheap, very easy fix to this problem by allowing you to direct the spray in whatever pattern you like. You will need the following materials:
1. a small length of PEX tubing of the kind used in modern plumbing. probably 6 inches in length is enough depending on how you decide to implement this instructable. The cost for this tubing is negligible. I just used a piece of scrap that I had left over from plumbing a sink in my house.
2. a lawn sprinkler which has aluminum tubes with a series of spray nozzles. I show this with the type shown in the picture but the same technique will work on any similar type.
3. cutting tools to cut the pex.
4. about 5 minutes of free time.
Step 1: Cut the PEX Into Lengths
Step 2: Cut the Tube Along the Side
I then used tin snips to cut the PEX along one side so that it can be opened slightly. You will probably notice that the PEX is curved in one direction. It is best to make the cut along the inside of the curve so that the resulting piece follows the curvature of the sprinkler tube more closely.
Step 3: Open the Slice
Now use some pliers to bend open the tube so that it is easier to fit onto the sprinkler.
Step 4: Install the Tubes on the Sprinkler
Now you can fit the tubes on to the sprinkler and slide them back and forth to whatever position you like in order to cover various sets of spray nozzles.
When the water is flowing it will try to follow the easiest route and if you have plastic pex over a given nozzle it increases the pressure at that nozzle and so less water will flow there. You will still have a small about of water escaping beneath the covered nozzles but the bulk of the flow will go through the exposed nozzles instead.
In fact, you will notice that, after you cover several of the nozzles, the remaining ones will spray further. This makes it clear that more water is flowing to them.
Step 5: Conclusion
I have used my modified sprinkler to water in tight areas between houses while minimizing the amount of spray hitting the walls, I have used it to water grass on both sides of sidewalks and driveways without wasting water in the middle on the concrete, etc.
I hope you find this a quick, cheap, and useful way to mold your sprinkler spray to water in a more efficient manner.
Have a great summer!