Problems with drip irrigation

The City of Arroyo Grande, CA encountered these problems with drip irrigatoin systems.

• A survey of landscape professionals and homeowners had “drip irrigation” as the highest maintenance of irrigation systems; it requires constant monitoring.
• Most maintenance people are not familiar with drip system repair, maintenance or even simple scheduling – there are too many different systems.
• And less familiar are home-owners.   For most efficient use, systems require pressure regulation (usually pressure reduction); a bit of information rarely shared at purchase.
• Often shoddy products.  (There are quality products available but that’s not usually what people are looking for with “drip” systems – usually people are seeking a cheaper irrigation solution).
• Products are constantly being introduced, often disappearing after a few months; hence, failed products become hard to replace or impossible to find or repair.
• Small tubing often becomes clogged from hard water and although new designs include filters and self-flushing emitters, they are costly.
• The tubing/system is unsightly.
• And because it’s unsightly, tubing is often covered by mulch or plant foliage, making it difficult to monitor the effectiveness of the system.
• Most gardeners, amateur and professional, often aren’t aware of a clog in the system or other maintenance issue until the affected plants begin to show signs of stress.
• Easy prey for wayward mowers and other garden tools.
• Easy prey for kids and pets.
• Easy prey for rodents.
• Easy prey for vandalism.
• Provides no cooling effect for plants during hot spells.
• Does not wash off foliage as do sprinklers.  Yes, it’s a good thing to occasionally wash off your plants and it does not cause diseases nor “burn” the leaves.
• It’s not easy to water areas with quantities of small plants, such as in newly-planted groundcovers and bedding flowers.
• Because the system is black and above ground and because water remains in the main line, micro-irrigation often applies damaging hot water to young plants.
• The vast majority of our weeds in Mediterranean climates are cool-season weeds — the kind that come up with winter rains. Even with a drip system, we still get cool-season weeds.
• Salts build up at perimeter of wetted area; such minerals aggravate most root-rot organisms.
• It’s often necessary to run it long to provide “deep” watering and consequently creates a long-term low-oxygen environment.
• Does not push oxygen into the soil.
• Because the wetted area is much smaller when delivered by drip compared to sprinklers, control is more critical in application of water to avoid plant stress.
• A recent evaluation of landscape drip irrigation systems revealed an average uniformity of less than 20% (> 70% is acceptable efficiency).
• One peculiar disadvantage to drip systems: gardeners often replace plants that have died at the end of a drip system tube by placing a new plant in the exact same place as the existing tube end – regardless of the type, needs, or eventual size of the new plant.

THE  WORST ISSUE

• Drip systems do not promote an extensive root system, one that is deep and wide and not shallow-rooted — the very type of system that allows a plant to be truly drought-resistant in the long run.