Growing Quercus Suber. (Cork Oak)

Hi,

I'm in the process of landscaping my front yard. Since I want an Oak tree that doesn't get massive it has been suggested that I consider a Cork Oak (Quercus Suber.)

Has anyone along the California coast grown a Cork Oak (nursery grown), or inherited one growing on their property? Would appreciate your sharing your experience growing this tree. Specifically how frequent you water (do you use drip irrigation), this particular oaks growth rate per year and how you would rate this tree as a garden landscape tree.

Thanks.

Barb

I have seen this species growing in the Bay Area and Napa. I am sure it would do well for you too. It takes very little water once it gets established. I have seen some growing that had no irrigation and were surrounded by parking lot paving.

It is alot smaller than the native oaks and grows more slowly. Even after decades it will not be a big tree. It is trouble free, but, with the problems of disease that are attacking the native oaks I have no information if it will have problems as the diseases spread across the coastal areas.

I say try it.

Hi Dale,

Thanks so much for your observations and information. Did the trees that you saw carry a lot of folage on them? The reason I ask is that I haven't been able to find much information about the Cork Oak. However, I did find an interesting article about the Cork Oak as it is grown in Algarve, Portugal for the commercial harvesting of the tree's bark. The tree in the picture had very little folage on it but was very picturesque in its growth.

I did find some Cork Oaks here on the Central Coast that had been started from acorns but the grower wasn't able to give me any information about the trees needs or growth rate. The trees I saw were about 3 feet out of the can. I was hoping it would be an oak that would grow enough that I might be able to see it develop into a tree about 25 - 30 feet tall in my life time.

Barb

Cork Oak has a nice outline/shape/form (pick your term). The one that I spent the most time around was on the campus of the College of Notre Dame, in Belmont CA (south of SF about 35 miles). It was surrounded by parking lot, was about 15-20' tall, round top and full foliage, maybe 40 yrs old (?). If you were underneath it you would call it dappled shade, like most oaks. From a distance it looked like most any oak, until you got close to see the bark. Even close up they don't look much different than other oaks, their bark is not that remarkable, until you touch it. From 15 feet away looks just like a Valley Oak or any of the other live oaks that have fissured bark. Coastal Oak is the one with smooth, light grey bark.

It will need some water to get started, especially this time of year, unless you get some summer rain. I have heard that you are having another drought, that means the soil will dry out quickly because the soil around your new tree will 'draw' the water away. Using a wood mulch will help keep the water in the soil.

If you plant it soon I would say prepare the soil deeply and add some woody compost (no cow manure, it is a tree). The old saying is don't put a $10 tree in a 10 cent hole.

On watering you will have to use your judgement. The first month I would say every other day. Ask the nursery people how often they water the plants in their containers and do as the do. Always water the edge of the rootball, no water on the trunk.

After a month you need to do the finger test. Stick you finger in the soil, if it's dry then water. Use about 5 gallons per watering for a 15 gallon tree. Get some buckets and fill them the day before, to get rid of the chlorine and get the water up to air temp.

If you are going to be absent for extended periods of time you can use 1 gallon milk jugs to water. Take a pin and make a tiny hole in the bottom, put in a little gravel/rock in so the wind won't blow them around. Fill with water every other day or every three days depending on how hot, windy etc the weather is.

Fall is best for planting, around the 1st of Oct in your area would be my guess. Summer is ok if you can take care of the tree because you will see it begin to grow. Once it starts to grow new leaves you can give it some water soluable fertilizer at 1/4 the recommended rate.

Cork oak is a nice species, never gets too big.

I actually belong to a different school of thought on amendments when planting trees--especially if you have clay soil, if you amend the hole the roots are going to want to stay in the nice amended planting hole rather than going out into your nasty clay soil. That may be fine at first, but as the roots grow, if they don't go out into the soil they'll just circle round and round the planting hole and you can end up with a rootbound plant which is definitely not a good thing. This can also lead to the "clay bathtub" effect, you water your nice amended hole, but then the water drains very slowly out into the clay beyond the planting hole and the roots end up sitting in water. When I plant trees and shrubs, I always shake off as much of the container soil as I can (most of the stuff I buy comes in containers vs bare root, B&B, etc) and plant it directly in the garden soil. If you don't have clay soil though this doesn't matter nearly as much, I've just always had clay anywhere I've ever lived so that's how I do things.

I definitely agree though on the fall planting, that is a great time of year to plant things here, that way it has the nice cool weather and all the winter rain to help get itself established. If you plant it now, it's going to require a lot more babying and your chances of having it survive are lower. I can never resist the urge to plant things in the summer, but I have to say my success rate is much higher on things I plant in the fall, so for anything big/expensive/rare/hard to replace I always wait until fall.

Slix years ago we planted three cork oaks in front of our house. I've only had one cork oak before--it was in the lawn of a house we moved to in Saratoga (from Santa Barbara, btw) that was about 20 years old. We had two or three years of heavy rains (82-3) and about a third of the oak died off. Now we live on a hillside in the Evergreen area of San Jose. Our landscaper planted the lot in mid-July and installed a drip for these trees. Earlier this year we removed the drip. One tree is on the edge of a steep slope and has grown very well--we've had to trim a few branches that were blocking the sidewalk. I'm sure its roots reach the edge of the lawn so it gets more water. It was a better specimen than the other two--they were about 12 ft tall and spindly when planted--this tree is now about 25 ft tall.

Two other trees are on top of the hill. They were smaller to begin with and have grown more slowly. This is the first year they look like real trees. They are now around 15 ft and still a little spindly.

I like the cork oak because they are slower growing and are a little different. The landscaper planted the trees in amended soil. We have heavy clay soil here. Other than watch them grow I've done nothing for them. I may deep water the two trees once or twice this summer if they look stressed, but otherwise all I've done is to clip off too-vigorous sideways-growing branches.

If I remember to do it I'll go out later today and take a photo for you.

E Crane 3, Dale and Tourmaline,

I've read each of your posts and really appreciate your sharing of experience and observations with me about the Cork Oak.

Dale, I'm not familiar with Belmont. Is it inland from SF or were the Cork Oaks subject to the ocean air? Since posting the first time I've talked to several tree people here is SB and was able to go see a lovely 80 - 100 year old specimen that was inland from us. Non of the arborist could tell me how the Cork Oaks will react to the salt air.

Fortunate or not we have a sandy soil with blue clay 15 - 20 feet down. We lost all of my carefully cultvated top soil of 35 years when the front yard was stripped down. I'm not sure which type of soil presents more problems, sandy loam or the heavy clay. I've had both here in Santa Barbara but I infinitely prefer the sandy loam if enough admendments can be incorporated into the soil before and during planting.

I've copied all of your replies. . . .I think I'm convinced to try using a Cork Oak. . .now my only concern is whether I'll live long enough to see it reach 20 feet or more. (grin)

Thanks so much for all of your help.

Barb


This message was edited Jul 6, 2007 5:22 AM

Barb,

Did you read the comments these folks made in Plant Piles> http://davesgarden.com/pf/go/54410/ ?

Another good source for information about gardening in California is Sunset Gardening Guide. It is not an 'in depth' book, but, it hits the high points very well.

I think I remember seeing a Q. suber in Golden Gate Park, which has salt air. I fled SF in 1998 so it is difficult to remember all the plants in all the places I visited.

I think it worth a try.

Hi Dale,

I'm new to the Dave's Garden Web site and wasn't aware of the Plant Files that you referred me to. Thank you for sending me there. I read the information with a great deal of interest. The nursery that the site referred to dosen't grow the Cork Oak so will probably check out the nursery that has started this Oak from acorns. I had hoped to find a larger specimen but in a lot of ways it may be better to start with the smaller size. They had 40-50 trees in 15 gal. nursery containers, all 4 to 5 feet out of the can. The trees are healthy looking with good healthy growth. The nursery is located a little further inland than where we are and with so many microclimates in Santa Barbara it can be interesting to see how the differences affect the plants.

Because of all the information and observations that all of you have so generously shared with me I have decided to use the Cork Oak as a specimen tree in our front yard. I'm looking forward to starting our landscaping project.

Thanks again Dale.

Barb

Barb,

We are all here to help out.

About buying a specimen tree - do you know how big a hole you have to dig? Smaller is better in that respect.

At UC-Davis they did a study on planting trees from various sized containers. They found that within 5 years (not a long time) the smaller containers grew iinto the same size tree as the larger containers (and sometimes better).

And now your adventure begins.....if you get a chance send a photo.

This is not a cork oak>