Container Gardening Under an Oak Tree, North of a Tall Fence

I have just moved into an apartment with a lovely patio that faces south but is beneath a large oak tree and surrounded by a tall fence. In particular I'm concerned about my collection of lavenders in 12" pots; are there any suggestions other than keep them in as much sun as possible and outside the dripline of the oak tree? I gather that oak trees produce an acidic runoff, while lavenders appreciate sweeter soils.

Don't worry about acidicity. Oaktrees do not produce acid soils and there is no acid runoff. This is a myth. Oakleaves are usually acidic if tested with a pH meter but this also applies to a lot of other leaves. Decomposed oakleaves produce acidic leafmold but that is not the same. People often think that they can not grow plants under mature oaks due to the acidicity. In reality it is the excess shade, hard compact soil and heavy drain on water in the soil caused by competition by hungry tree roots and the dense canopy. The idea of acidic soil is not true.

If you can water regularily, you can even put the lavender under the canopy of the oak. However, you are right in trying to give it as much sun as atall possible.

Hello neighbor! You may be thinking about Walnut trees which are toxic to plants growing under them. Even so, I've been able to get a pleasant garden going there. What kind of an Oak tree is it?

You shouldn't have a problem but since your lavenders are in pots you could feed them a product that makes the soil more alkaline if necessary. Just get a ph tester from the nursery and talk to your local nursery person and of course you already know that they need sun. Check and see how many hours of sun you're getting. Most plants are OK with about 6 hours of sun a day. You may have to move them a little when the sun gets highter and the tree throws more of a shadow. You may want to expand into some shade plants which is a whole world of fun.

glasslady,

I remember getting to Pleasanton from Fremont via a two lane road. This was before 680 was built. If the tree is evergreen, you probably have a live oak, but it's best to be sure. Native live oaks in California are used to the mediterranean climate (Rainy winters dry summers) and can be killed by regular watering. If you garden under a native oak, try staying as far away from the trunk as possible. The non-native live oak, Quercus virginiana, loves water.

BettyDee

Evergreen and if the tree has really sharp leaves with multiple points on them that continually litter the ground, moths flying from it at this time of year, and a very fissured trunk, you have a California Live Oak. Don't get me wrong, I love the two in my garden. Water can be a problem, but it sounded as if you had a patio under it though and were container gardening so water should not be a problem. The tree behind the Horse Chestnut Tree is a California Live Oak.