I'm in the process of preparing an area in my front yard for an herb garden. There are several large, old Valley Oaks trees in this area and I've read that their root system shouldn't be disturbed or watered during the summer months. Some articles say that you shouldn't plant within 10' of the trunk and some say not to plant anything under the canopy. Since the oaks are large, if I avoid planting under the canopy, I'll have only a very small area to plant. Do you have experience with planting near oaks? On other areas of our property, there are manzanita and other small shrubs growing right up against the trunks of the oaks, but they are not watered during the summer months and survive on the winter rains.
Thanks for sharing your knowledge and expertise with us! AA
Sorry AM, I support the idea of nothing irrigated under the dripline/canopy of the oak. Like you observed, there are many native plants that thrive under oaks - only if planted in the fall before the winter rains in CA. Oaks often have roots 2Xs wider than the foliage, so keep this in mind re your herb garden.
Robert Kourik wrote:Sorry AM, I support the idea of nothing irrigated under the dripline/canopy of the oak. Like you observed, there are many native plants that thrive under oaks - only if planted in the fall before the winter rains in CA. Oaks often have roots 2Xs wider than the foliage, so keep this in mind re your herb garden.
I am not trying to sound rude I am simply wondering the reason why? I was thinking about doing minor cultivation of things that like acid soil and don't need a lot of water but might require some.
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posted 3 years ago
Oaks are prone to crown rot - phytophera. Summer water in the rain-free summers here in Northern CA can promote this disease. If you live in rainy summer areas go for it.
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Location: Zone 9b Nothern California
posted 3 years ago
Thanks for the info. There's a small nursery in Chico that carries California natives so I'll visit them next fall and see if they have something that would be a good fit.
A bit of observation will reveal that valley oaks grow right up to the banks of the Sacramento and other perennial and seasonal waterways, so I would say that some root access to supplemental water won't be harmful...in fact otherwise. What they don't want is wet right up against the base of the trunk in the leafed-out season. I have both blue and valley oaks in my yard, and while I'm not irrigating anything under the canopies, I am irrigating gardens and other plants nearby outside the dripline. I regularly find oak roots in the gardens, sometimes quite a distance from the nearest oak canopy. Some of these roots are new, so they are apparently after the moisture and nutrients I'm adding to the gardens. Between roof runoff, slowing water runoff in the drainage areas by means of check dams, and my irrigation, I think this may be responsible for the higher and more regular yields of acorns from the oaks in the yard as opposed to out of it (good for me and my animals, since we eat them!)