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Penny Carnathan

Penny’s a Nurture And Hold (NAH): Nah, I won’t pull that out yet, it’s still got a green shoot. She likes dragonflies, lady bugs and new stuff only after weeding, pruning and fertilizing.

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Will your oak tree crush your house in the next big storm?

Posted Jul 26, 2009 by Loren Omoto

Updated Jul 29, 2009 at 10:29 AM

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I don’t have oak trees. The last big tree I had was a Florida maple. After the hurricanes in 2004, I had an arborist check it out and learned it was in bad shape. I paid a few hundred dollars to take it out. (I’d just had the kitchen remodeled and I really didn’t want to see that maple sprawled across my new granite countertops.)

I’d love shade, but it can come with a price. During a special presentation last weekend, county forester Rob Northrop spelled out that price for members of the Town ‘N Country Garden Circle.

Town ‘N Country has a lot of laurel oaks—huge shady behemoths. But at 40 or 50 years old, they’re hitting maturity. And, along with old age, many have serious health problems. Some are downright dangerous.

Town ‘N Country also has a lot of live oaks. These, Rob says, pose fewer problems. They live forever (250 years or more) and they don’t have the same health issues that laurels have.

Is your big oak tree ready to keel over or drop a big fat limb on your car? Or (gulp) your kid? No one can say for sure (Rob emphasized that!) but he gave us some excellent tips for doing an oak self-exam.

1. Is it laurel (perhaps old and dangerous?) or live oak (good)?

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The laurel has an ironed-flat leaf—the one on the left. The live oak’s leaf, right, is slightly cupped; the underside edge is slightly turned up.


Look at the bark.

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The laurel’s bark is smooth, compared to live oak.

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The live oak’s bark is extremely rough.


2. Are the connections good?

Look for very pronounced V-shaped connections between branches and trunk, and trunk to trunk. These are weak and under a lot of pressure. They can snap. U-shaped connections (and soft V’s) are strong.

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The tree in the foreground has a pronounced V to the right; it’s a third trunk. The tree in the background has a large limb connected with a soft (strong) V.

  Having an arborist prune back the trunk or limb connected with a weak V can help reduce the weight and stress on the joint.

3. Are there open wounds?

Holes in the trunk are evidence of cuts that never fully closed. Fungus enters these wounds and rots the core of the tree, which may look perfectly healthy on the exterior.

Pruned roots – to make way for sidewalks and pavement – invite rot at the tree’s base.

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Laurel oaks and water oaks have poor wound-healing capabilities, which increases the chances they have fungal infection and core rot.


4. Look up. Are there dead branches at the top of the tree?

They indicate a compromised root system or fungus – the tree can’t move water and nutrients all the way up its crown. The dead branches will slowly migrate deeper into the crown.

5. Look inside. Does the core have rot?

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Here’s a way to check, but it comes with no guarantees; there may be rot, just not in the area you check.

Get a small-diameter drill bit the length of which equals the trunk’s radius (measure the trunk’s circumference and divide by 6.28 to get the radius).

Drill into the trunk on a side where it may be compromised, such as facing the street. If, while drilling, you suddenly meet no resistance, you’ve hit a pocket of rot. At the very least, a third of the radius should be rot-free to consider the tree relatively safe.

Rob promises the small wound created by drilling won’t hurt the tree.


6. You think the tree is an old and dangerous laurel oak and you’re pretty sure it should be removed.

If you live in Hillsborough County, you’ll need a $35 permit. If you’re not certain the tree is a goner, ask for a county arborist to come out and take a look. Go to http://www.hillsboroughcounty.org and type “tree removal” in the search box or call (813) 272-5920.

If you live in Tampa, tree removal permits for protected species that meet certain criteria cost $99 per property. Permits to remove grand trees, those measuring 34 inches in diameter at chest height, are $128 if the tree is hazardous. Apply for permits through Construction Services, 1400 North Blvd., Tampa; (813) 274-3100 or http://www.tampagov.net (click on Construction Services in the “department” search box. Then click on “permits.”)
Grand trees will be evaluated by an arborist from Parks and Recreation, (813) 274-5764. If the tree is in a public right of way, the city will take responsibility for it.

7. You want to hire an arborist to evaluate your tree or prune it to reduce risks.

Under “tree services” in the Yellow Pages, look for companies with the International Society of Arboriculture label, which includes an oak leaf. Get two or three bids or estimates, Rob advises—these are big-ticket jobs.

8. You’ve lost your laurel oak and you want to replace it with another tree.

Have your soil pH tested to make sure the tree you choose will thrive in your dirt. Visit urbanforestry.ifas.ufl.edu/Hillsboroughtrees.shtml for a list of trees considered acceptable by Hillsborough County. (Laurel oaks are on the list, which just seems wrong. But Rob notes it’s a great tree that grows quickly and provides a lot of shade. People just need to know what to expect with any tree they plant.)

He recommends cross-referencing that list with the University of Florida’s lists of wind-resistant trees for storm protection. Go to edis.ifas.ufl.edu/FR175 and edis.ifas.ufl.edu/FR174 and click on “click here to view PDF.”.

9. Get tips on locating and planting your new tree at urbanforestry.ifas.ufl.edu.

10. Town ‘N Country’s problem came to light because garden circle member Rob Gamester took the county’s new Community Forest Steward class. Armed with knowledge, he recognized the impending crisis in his neighborhood. To learn about the fall forestry class, which runs Oct. 29 through Dec. 3, call (813) 744-5519, ext. 104. The 32-hour course costs $30.

 

 

Reader Comments

Por (Janna) on July 29, 2009 (Suggest removal)

Thanks to your info and photos, I think I’ve correctly identified the monstrosity in my back yard as a live oak. Thank goodness!

Suggest removal

Por (Dave C) on August 04, 2009 (Suggest removal)

Great. A huge laurel oak behind my 54 year-old house. Not even on my property, but the branches are covering my back yard. I’m going to miss that shade.

Suggest removal

Por (Dave C) on August 05, 2009 (Suggest removal)

I don’t think there’s much to worry about. The worst that could happen is it crushes the creepy shed in the back. I’ve only peeked in it since we moved here in April.

Suggest removal

Por (Dave C) on August 06, 2009 (Suggest removal)

I don’t feel so lucky now. It figures now that I start talking about it on a blog… A branch fell while I was at work today. a BIG one. It crushed the front of our creepy shed. Also busted our next door neighbor’s fence. It’s safe to say this tree isn’t safe anymore. Now I have liability questions…

... and I could use a tree service.

Suggest removal

Por (Dave C) on August 10, 2009 (Suggest removal)

Update:

I called Independednt and they were able to remove the fallen limb from the back yard. $495!!! Unfortunately, our healthy orange tree was beyond repair and had to be removed. We have a small circular stump where it used to be. As far as the remaining branches go, there are 3 that threaten the house. I have another arborist taking down our remaining branches. $1500 for the remaining large branches (over power lines leading to the house). Looks like I’m buying cheap plants this year.

Suggest removal

Por (Dave C) on August 10, 2009 (Suggest removal)

Oh, I know.

To not have to worry about it again is fine by me.

Suggest removal
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