To water or not to water ?

You don't need anyone to tell you how important trees are to our community. They not only add incalculable visual aesthetic value to our town and neighborhoods, but also provide significant environmental benefits such as summer cooling of our homes, streets, yards, etc. They also produce oxygen in exchange for our production of carbon dioxide.

How often do we give them some attention or even a nod for all they do for us? Not often enough.

Now that summer is upon us, it is the most important time of year to give trees some of that missed attention by asking yourself &

or your trees if you are so inclined &

Are the trees in my yard getting enough or too much water? To answer this, let's take a look at how a tree goes about getting the water it needs.

If asked, most people would think that deep rooted trees such as oak, walnut, hickory and hornbeam are designed to retrieve water and nutrients from deep within the soil, and the shallow rooted trees such as conifers like pine, cedar, spruce, redwood, but also other nonconiferous trees such as sycamore and cottonwood are best suited to collect frequent but often not too intense rains or tap into nearby streambeds.

The truth is, although the amount of water each tree needs will vary by type and a host of other factors, they all obtain their water from the near surface root system. These are called the feeder roots. Feeder roots often have very fine root hair that increase the area for the uptake of moisture and nutrients and the feeder roots of other types of trees establish mutually-beneficial relationships with certain mychorrhizae (fungi) to assist in uptake.

OK, now we know we need to get the water to the near surface root system. Most people would assume to apply the water (and fertilizers) at the drip line of the tree since after all that's where the majority of the rainfall would make it to the soil. Although the reasoning is correct, the truth is research has shown that feeder roots can extend 7 to 10 times the drip line of the tree.

Then the age of the tree comes into play. In general, if the tree is young or newly planted, supplemental summer water is a must. If it is an older established tree extra water may not be necessary, but it is still wise to look the tree over and if its leaves don't look droopy or wilted on a hot afternoon there's no need for additional water. Sound simple? It really is. And best of all, proper watering will not only benefit the tree, but can help conserve precious water as well.

Other less obvious, but no less important factors also come into play when considering the seasonal watering needs of our trees. Some trees, like the native oaks and the madrone, do not respond well to abrupt changes in watering patterns. Also, even though a mature tree may not have required supplemental water in years' past, it doesn't mean it may not need a boost in water this year, especially as we approach the peak temperatures of summer.

Finally, another important consideration is how the projects we may undertake on our property this summer, such as home construction, room additions, surfacing driveways, building pathways, etc. affect our established trees. In such cases, care should be given not to disturb the root zone of the established trees, unnecessarily compact the soil, or worse; sever existing roots.

If you would like more information about a particular tree in your yard and its watering needs look for the "Recommended Street Tree Guide," a 72-page booklet published by the City of Ashland through its tree commission &

available at the Ashland Community Development Engineering Services Building at 51 Winburn Way or online at /Page.asp?NavID=1033. A certified arborist can be a great resource as well, and the Southern Oregon Research and Extension Center not only is a great source for information but can also provide referrals to master gardeners who have graduated from their education and training program.

The Ashland Tree Commission is made up of seven volunteer members appointed by the mayor and confirmed by the Ashland City Council. In addition to updating and maintaining the "Recommended Street Tree Guide" and participating in the annual Tree of the Year award, the commission also acts in an advisory capacity to the planning commission in the development process with respect to landscape design, suitable plantings, protection of natural vegetation, and tree requirements. There are current openings on the commission. Interested persons are encouraged to contact the city recorder's office at 488-5307 for further information.

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