Wednesday, July 1, 2015

Don't let the drought kill your trees!

Not a day goes by without the mention of the word drought in California. At this point, everyone understands how serious the problem is, and what steps need to be taken to help.

Yes, we need to save water, but more important, we need to use water wisely, and that means watering your trees to keep them alive.

Frequently you hear people talking about the evils of landscaping. In most cases, they're right. Bright green lawns serve no purpose aside from aesthetics. Places to play? Theoretically, but outside of the 4th of July, I can't ever remember seeing a neighbor play in their front lawn.

Because of how wasteful these lawns can be, most cities have limited watering days, and encourage people to simply let their grass turn brown.

That's perfectly good advice - as long you as you remember to keep your trees watered!

Unlike grass, which has little use outside of athletic facilities, trees come with a variety of very important benefits.

This article provides some great links into a lot of the research done on urban trees, but here is a summary of the benefits:
  • Higher property values
    • The presence of street trees in front of a house raised the property value by $8,870 and reduced time-on-market by 1.7 days
    • Average price premium of 4% for homes located in the greenest neighborhoods, and a 7% discount for homes in the least green neighborhoods
  • Decrease in crime
    • Large trees indicate a neighborhood with strong community investment – and thus, more effective policing
    • More desirable environment means more eyes on the street to deter crime
  • Health
    • Air quality improvement (very important in Fresno!)
    • Decreased stress
    • Noise abatement 
    • Reduction in heat island effect (again great for Fresno!)
    • Can result in lower traffic speeds = less collisions and fatalities
    • Healthier babies/births
  • Pedestrian activity
    • Shade leads to more outdoor activity (more health!)
  • Environment
    • Better air quality again of course
    • More shade means less use of A/C - less electricity in turn means less emissions
      • Also a great cost saver! 
    • Improved ground stability / erosion prevention 
    • Habitat for animals
Again, the article has links to research papers with citations for these benefits.

There is simply no denying the importance of large, healthy trees, especially in Fresno, with sweltering heat and abysmal air quality.

Letting a tree dry out and die could mean losing all these benefits. This is especially dangerous because a grassy lawn can go from dirt to luscious in a couple of months, (when water is available!) or even in a couple of hours, if you simply want to roll out sod. But a good tree can take years if not decades to reach maturity. Letting a tree die means losing out on the benefits for a very long time.

 photo Clovis trees_zpsfe2va031.png
These giant trees are lucky enough to draw water from an underground canal, but most Fresno-area trees need your help


The Fresno Bee recently had a good article letting people know what to look for in their trees:

If your citrus trees continue to drop immature fruit, if the leaves curl up (a moisture conservation reaction) or if leaf fall is heavy, consider increasing irrigation. Sprinkler water will not soak the soil to the necessary depth of at least one foot. When the top three to four inches of soil is dry, use soaker hoses or a bubbler attachment on a hose to slowly soak the soil for several hours. Plan on weekly irrigation; more often when temperatures are high in July. Supplement irrigation with shower bucket water as needed.

Redwood roots form a shallow mat that lies just under the canopy. The feeder roots that draw up rain water and fog condensation droplets lie at the outer edge of the canopy. Supplemental slow irrigation by soaker hoses, drip emitters or bubbler attachments should be placed at the drip edge and the soil should be soaked to a depth of one foot. Allow the fallen needles to remain under the tree as a water-conserving mulch and do not cut off lower branches that shade the tree roots.

Fresno Bee



From what I understand, the watering restrictions are about automated sprinklers. You can still go out with a hose to water your trees. This way, you can let the grass die off while ensuring your trees get what they need.

Don't forget to only do this in the early morning or late evening, and to always use a nozzle so no water is being wasted.

Another important tip is to use mulch. It is very inexpensive, and it blocks the sun from drying the ground, thus meaning more water is available for your tree, rather than being lost to evaporation. The mulch also blocks weeds and grasses which steal your water.

If you have a tree on the street, or one near your property that is being neglected, try and adopt it. If your neighbor lets their tree die, it hurts you as well.

The Sacramento Bee also has a video with some tips. An important one is to remember that trees absorb water slowly. Flooding your tree is just going to waste water. Instead, they suggest setting out a bucket with holes that will slowly release water, or even using ice. (That wouldn't work for us, our dog would eat all the ice!)

A fancier solution is a soaker hose (hose with holes) attached to a timer. That way you turn it on, and if you forget to turn it off, the timer will block the water for you.

Here are some additional details on using that:

The drip line, which marks the edge of the tree canopy, is a good place to start watering. To “deep water” the tree, lay a soaker hose in a ring around the tree just inside the drip line and continue in a spiral outward. Let the hose run until the water soaks in to a depth of about 8-12 inches, but watch for runoff, especially on clay or compacted soils. Depending on soil type and flow rate of the hose, this may take a few minutes to a few hours. Check the soil to make sure you’re not watering too deep or too little. To prevent runoff you may want to install a simple battery operated or wind-up timer to shut off the hose after a certain amount of time. If water runs off before water soaks in, turn the water off and turn it on again after a couple of hours of soak-in time. If the tree you are watering is small, start laying the soaker hose closer to the trunk or hand water.
Save Our Water

An even fancier solution is to use your existing sprinkler system, but adjusting the heads and locations so that they only water your trees and bushes. This works well if you're abandoning your grass.

Whatever method picked, it is important to remain committed and to water every week. Trees can do pretty well with limited water, but once a tree dies, there is no way to bring it back.

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