Brown patches and uneven plant growth can be caused by a number of factors, but in this article we are going to focus specifically on sprinkler systems as the source of the problem. Below are several common problems and some tips for fixing them.
Incorrect sprinkler head height is one of the most common problems leading to brown spots and poor growth. Heads installed at incorrect heights can also lead to damage to the sprinkler system.
Sprinkler heads that have been installed too low aren’t able to rise above the ground or turf level, or the level of the plants directly around them. This prevents the water from spraying properly, and often leads to coverage gaps and flooding around the sprinkler head. Additionally, sprinkler heads that are too low are more likely to have retraction problems and mechanism failures. This is caused by dirt entering the internals of the sprinkler head.
Heads that have been placed too high are a tripping hazard, and are a risk that could damaging lawn mowers or other landscaping equipment. The easiest way to correct this is to dig out around the head, disconnect it, and reconnect it using funny pipe or a swing joint, which can be positioned to exactly the right height.
Another common cause of incorrect sprinkler head height is the natural growth of surrounding plants. A sprinkler head that was installed correctly near a shrub may need to be adjusted as the plant grows. Sprinkler heads watering ground cover plants will also need adjustment.
Over time, ground levels can raise or lower (soil is washed away with rain and flooding, and built up with decomposing leaf matter, grass clippings, etc.), which can cause a sprinkler head to be too high or too low. Either way, the best solution is to dig it out, remove it, and reconnect it using a swing joint or funny pipe. All sprinkler systems should be checked periodically to verify that the heads are still at the correct level.
Clogged sprinkler nozzles are caused by dirt or debris working its way into the sprinkler head. This can prevent the sprinkler head from spraying properly, causing gaps in the spray pattern, which will lead to brown patches. The first step in diagnosing brown spot is to observe the sprinkler while it is running. You’ll be able to see if overgrown plants are blocking the sprinkler, the head is broken, or the spray pattern is being internally disrupted.
Note: Don’t try to remove a nozzle by prying at it with a screwdriver. Both rotor and spray nozzles are easy to remove, but must be removed carefully to avoid damage.
Wrong spacing of heads
Even if sprinklers appear to be spraying evenly over an area, there may be gaps in the coverage. When planning and installing sprinklers, it is important to lay out the heads with “head to head” coverage. This means that the spray from one sprinkler head should reach the next closest sprinkler heads, and vice versa. Head to head coverage creates optimum watering overlap, and help compensate for spray pattern imperfections.
Uneven growth or brown patches in your lawn may be an indication of damaged or clogged heads, or improper installation or placement. It is important to check all these possibilities, and repair or correct any problem areas to maintain a healthy lawn. Often, poor coverage will not manifest itself until severe hot, dry weather conditions prevent your lawn from receiving supplemental water through rainfall. New plantings can also reveal problem areas, as they have not yet developed mature root systems. additional watering times or hand watering can help, but the best solution is to adjust your sprinkler system properly and clean or repair any damaged or clogged heads. A well-maintained, properly installed and adjusted sprinkler system will keep your landscape well-watered, beautiful, and healthy.