Monterey County Magazine - Winter 2007-2008
Gardening in the Urban Forest
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When Father Serra first landed on the sands of Carmel Beach he would have seen open groves of live oaks and dense clusters of Monterey pines above the dunes with perhaps a twisted cypress on a rocky crag. Over 300 years later the forest is much denser, having been augmented with hundreds of pines, cypress, eucalyptus, and acacia planted during Carmel’s days as an emerging arts colony. But many of those trees, other than the oaks, which live for hundreds of years, are fast growers that are now aging and failing.
The most important aspect of keeping the urban forest healthy is the addition of new disease resistant trees to replace those being lost. Dedicated citizens, Friends of the Carmel Forest, strive to see that every fallen tree is replaced with an appropriate new specimen with the medians and street sides are rich with newly planted trees. But this is no easy feat, with ground space in the city pricey and scarce. For landowners, the cost per square foot becomes so intense there is an urge to use all the available space for building opposed to room for massive 100ft Monterey pines to take root. But if we are to maintain the unique atmosphere that makes Carmel so special, the forest canopy must continue to have room to grow.
At ground level it is the gardens blooming under the trees that catch our attention most. Gardening under native trees is a challenge. Roots are everywhere and some trees grow dense mats of thin surface roots to wick up irrigation moisture. Everything in nature has a purpose and the constant rain of leaves and needles from the canopy helps to build the soil, creating a rich moist layer of duff ideal for starting a new garden. Instead of raking away this treasure, we should be allowing it build slowly, feeding not only our gardens but also the trees themselves.
Now, I will be a contrary voice to common opinions about irrigation. Common thought is that oaks quickly decline under irrigation. While this might be true on heavier soils in warmer areas, in cool summer Carmel where the underlying soil is mostly sand, the ancient oaks continue to thrive with regular irrigation from golf courses or gardens. For new gardens, native plant experts now recommend the use of micro-irrigation, tiny water sprayers that mimic the fog drip of summer. These miniature spray jets installed as part of a conventional dripper system deliver a light mist of water near the soil surface, enough water to encourage a wide spreading root network in newly installed natives without disturbing an oak’s deep delving root system.
When it comes to plant choices, you might be surprised to find that there’s a wealth of plants that will thrive in the dry, often shady conditions of the urban forest. I recommend plants that give more than one season of interest. They flower but also have interesting leaves, or unusual flaking bark or colorful berries and are both drought tolerant and deer resistant. While I love to recommend California natives, there is nothing wrong with well-behaved “exotic” plants. This includes the varied clan of Grevilleas from Australia who are winter bloomers in red, pink, orange or yellow on evergreen shrubs from ground cover to tree stature. Then there is the combination of spring blooms with spectacular leaves in every shade, from deepest chocolate to pink-flecked, orange, and lime in all of the new Heuchera and Tiarella and their crosses (called Heucharellas!). They give a constant foliage effect all year that cannot be rivaled in shade.
If we continue in our efforts to be sensitive to the needs of our urban trees, take the time and space to renew the forest with resistant species, and plant with a interesting, low-water use palette of native and compatible flowers we will continue to enjoy our urban forest and ensure it’s continued survival.
Dave Egbert, The Coastal Gardener
