dealing with tree roots and gardens, root barriers

[che]

I read this question on a gardening forum, and I don't have an answer (I don't garden around the trees much...that's where I SIT.) I'd like to get the viewpoint on this question from those interested in the health of the tree as well as the ease of making a garden close to it. Thanks, Che

Here 'tis:

<i>I have big oaks all around and cutting them isn't an option (although I'd like to).
Some beds, we've put in fiberglass panels (2'deep )on the perimeters as root barriers, otherwise the big oaks 'feeder' roots choke out many plants (daylilies included) in no time.
I'm not finding new oak roots in those beds, but I'm wondering if I can get away with something less than 2' with new beds or if for long term, I should go the max width of panels and dig them in a full 2'. Or would galvanized metal be better choice for new root barriers?
Actually, I don't dig the trenches for the root barriers myself, that's Hubby's department, but I need to know also, how close to the trees we can put them in? Is the dripline a good guide?
(I wouldn't mind going right up to the trunk with some of these big oaks.
If they die a little at a time, Hubby won't blame it on me
Thanks, Lisa</i>

 

[che]

Thanks for your reply, Brian.....but that's kinda why I wrote....there are alot of people (most, I would hope) who don't share that opinion of oaks (or any tree for that matter) but are also looking for an an option to gardening near trees. IF they can, HOW they can.....without doing damage to the trees. I can't imagine anyone truly disliking an oak, especially a gardener.....their leaves make the BEST mulch available (IMHO.)

I can ignore this woman's post, or try to give a reply back that WOULD help the trees involved.


Please don't label me a tree hater on my posts about Osage Orange this upcoming winter. We have a love/hate relationship....'hedge' and me.

Che

 

[John Paul Sanborn]

Gardening in the immidiet root zone of trees is problematic. Shigo refers to the realted decline in trees "garden disease".

When evr people ask about putting in gardens in the Critical Root Zone (CRZ) I always recomend fire and forget perrenial types like hasta and lilley-of-the-valley.

recurent damage ro roots in the CRZ can lead to rootrots in the supportive roots and decline noticable decline in the crown. Especialy if one is doing bulbs and annualls every spring summer and fall, year in and year out.

So only if it is a small tree that is not important to the landscape and one can afford to Remove & Replace every 5-10 years.

I 'now, you get gardeners hat say they do it all the time, but that is anecdotal observation. We supply imperical data, based on vuage studies done somewhere by someone we cannot recall at the time

 

[MasterBlaster]

Why doesn't she use something like Biobarrier Root Control System, from Sherrill? Don't that stuff work?

 

[Tom Dunlap]

Che,

It sounds like Lisa is a tree hater. It doesn't make sense to put in barriers around mature trees just to keep roots out of gardens. Its possible to garden around mature trees. Just takes more care. Designing plant materials that don't need replacements and using mulch to get the plants up a little higher in the rhizosphere.

Tom

 

[che]

Sounds like this is not a really 'simple' question. I read a few more current posts, and did a search on roots and CRZ, finding a bit more. Beyond my ability (or desire) to convey in a reply to this woman's post. If it's difficult for a professional to convince people to consider the trees while they are busy putting together their 'look'....I would have 'no chance at all'.

I will probably take some of this info and use it at my own home, so don't consider your time ill spent....THIS time. I am a gardener....but as far as I'm concerned, the trees are part of it that I wouldn't want to compromise. I need to find out more about the CRZ....I did pick out the rule of thumb: 1" trunk radius means 1 foot CRZ (which so far I'm assuming means active, important feeding roots.)

forget perrenial types like hasta and lilley-of-the-valley

This confuses me. While I understand the repeated damge if planting with annuals, why, if someone is going to plant around a tree would you not recommend a perennial like hosta (because of the size of the roots?), or a ground cover (shallow roots) like lily of the valley?

I realized yesterday that I DO have an area where I planted around the tree....I put a circle of thin but large flat stones (with fossils) around my pin oak by the house. I ship daylilies bareroot, so I use alot of water to wash them off....I normally do the rinses near a plant/tree/bush that needs the water anyway...so I put these rocks out to lay the plants on and the tree would be getting the benefit of the extra water. I worked a couple plants in by hand when I set it up.

Thanks for all suggestions, again...I think I'll just stay out of the original post's quesiton.

Brian....I'm sure looking forward to be able to 'gripe' about my 'hedge battles'......there's a smell of fall in the air early this morning, shouldn't be too long....

Che

 

[Guy Meilleur]

mb and Tom have the right ideas--plant higher, use fabric.

My experience is that people are excessively freaked out about the notion of adding soil above a tree's root system. Consider where the soil level would be if no one raked the leaves and twigs away

That's the height that high-organic soil can be added, imo. Lay down fabric, add soil, and plant your hostas ferns etc. The oak roots will connect to mycorhiza going through the fabric(see the bright gold strands!), it's a win-win situation.

The 1' per 1" diameter is a rough ballpark thing--1.5' is more like it on old trees. digging down to install panels is insanely destructive, but that doesn't make Lisa a tree hater, just a flower-lover who is underinformed about trees. Lighten up, Brian!
Betcha never heard that before, huh?

Planting between big roots makes a great effect and if an associate like ground orchids are used it's good for the tree. Symbiotic. Don't take my word for it--go into oldgrowth forest and see them growing together there for yourself.

Trees like to have friends around them. It's only natural

 

[Kneejerk Bombas]

Originally posted by Guy Meilleur
mb and Tom have the right ideas--plant higher, use fabric.]

I think Tom said it was not good idea, it's just you and MB on this one.

Originally posted by Guy Meilleur

My experience is that people are excessively freaked out about the notion of adding soil above a tree's root system. Consider where the soil level would be if no one raked the leaves and twigs away

Yeah, thats why trees in the forest don't have root flaires, 'cus the soil gets deeper and deeper from the leaves. In really old forests the trees are short 'cus the soil is so deep

Originally posted by Guy Meilleur

That's the height that high-organic soil can be added, imo. Lay down fabric, add soil, and plant your hostas ferns etc. The oak roots will connect to mycorhiza going through the fabric(see the bright gold strands!), it's a win-win situation.

Yes, soil piled up on tree roots improves soil gas exchange, the deeper you go with added soil, the more oxygen gets down to the roots. They don't get really good oxygen levels until you bury them a foot or two, especially if you use clay soil on top, that holds the oxygen in real good. Consider using plastic too, instead of fabric. If you are going to do a job, do it well, and today we're killing trees.

Originally posted by Guy Meilleur

The 1' per 1" diameter is a rough ballpark thing--1.5' is more like it on old trees. digging down to install panels is insanely destructive, but that doesn't make Lisa a tree hater, just a flower-lover who is underinformed about trees. Lighten up, Brian!
Betcha never heard that before, huh?

Are you talking about putting a foot of soil over the roots for each inch the tree is thick? Cool. that's what I do too.
Some people think that is a reference to staying away from roots in the zone of rapid taper, but I say just cut them off, I have yet to see a tree die in the first week after cutting it's roots off, so it must be ok.

Originally posted by Guy Meilleur

Planting between big roots makes a great effect and if an associate like ground orchids are used it's good for the tree. Symbiotic. Don't take my word for it--go into oldgrowth forest and see them growing together there for yourself.

I like the way you try to throw one serious statement in with all the other (sarcastic?) nonsense.

Originally posted by Guy Meilleur

Trees like to have friends around them. It's only natural

Or two.

Now for my serious comments:
Tree care is easy. Don't cut off the tops. Don't cut off the bottoms. Don't cut off the roots. Don't compact the soil. Don't bury the roots.
These actions alone would save 97% of trees, yet there are tree professionals who don't understand.

 

[SpikeSupra]

Mike,
What if I cut off the top AND bury the roots, won't that balance things out?

 

[Guy Meilleur]

Originally posted by Tom Dunlap
Its possible to garden around mature trees. Just takes more care. Designing plant materials that don't need replacements and using mulch to get the plants up a little higher in the rhizosphere.

Tom [/B]

So, Mike, read the above very carefully and you'll see I'm not alone in believing groundcover plants can work under trees.
As for fill soil, note I said high-organic, just like the composted leaf litter that would be there if it wasn't raked. Compost happens, and if it's removed it should be replaced.

I've seen a lot of root systems suffocated and I've seen a lot rejuvenated as they colonize good soil that's not applied too deep. It's just reversing human-caused erosion, right? Added soil, like reduction pruning,can be overdone but can help a tree if done with moderation.
"There are no absolutes in Nature"--A. Shigo, ANTB

 

[Kneejerk Bombas]

I read Tom's idea as thoughtful and in keeping with proper care of trees. He isn't advocating putting down fabric and additional soil. Just carefully planting perennials in shallow, carefully dug holes.
If annuals need to go in small planting holes could be dug in with a jet stream from a garden hose. Again, using Tom's idea of shallow planting and utilizing mulch to make up the difference.
Comming on this site and saying that from an arborist's point of view burying any root is OK, is just wrong. Same with saying topping is ok, or bottoming, or compacting, or cutting.

 

[Kneejerk Bombas]

Spike,
I wanted to make a seperate post to answer your question.
Yes, that would be fine.

 

[Kneejerk Bombas]

Doesn't the amount of interference that a tree can handle depend on the condition of the tree to start with?
A young healthy tree, of a vigorous species, can take more abuse than an old, over mature tree, of a slow growing species, growing in urban compacted soils.
Can we agree that the safest thing to say, without seeing the tree, is to just suggest the tree owner does what is best for the tree?
Urban trees face a lot of challenges; pollution, compaction, trenching, poor soils, over trimming, lawn mower blight, monocultures, ect. Any or all of these (and more) stresses could occour at any time in the trees life. One owner could water and take careful care, only to have the next tree owner do nothing but cut off it's lower limbs and park his leaky 1981 AMC Pacer under it.
A suggestion that covering the root area is ok, based on excellent tree health, might turn out to be the death of the tree when two months later there is an electric wire trenched by on the other side of the tree.
Trees can live for hundereds of years, we own them for a national average of 7 years.

 

[Guy Meilleur]

Originally posted by Mike Maas
Can we agree that the safest thing to say, without seeing the tree, is to just suggest the tree owner does what is best for the tree?
** Wee agree.
One owner could water and take careful care, only to have the next tree owner do nothing but cut off it's lower limbs and park his leaky 1981 AMC Pacer under it.
**one owner can leave the fallen leaves to recycle, the next rake them all away and plant grass. What's an arborist to do? Begin the cycle again by replacing the lost compost with compost and mulch.

Down here, red maples love new soil, and old white oaks like it fine. In my experience most any old tree with roots above grade will tolerate some porous fill in between. Red oaks, hickories, ya gotta be way more careful with the intervention.

covering the root area is ok, based on excellent tree health, might turn out to be the death of the tree
** Yes, and it might turn out to be its salvation. Species, condition and site specific, like most tree care issues.
"There are no absolutes in Nature", right?:angel:

 

[John Paul Sanborn]

Che, I shoulda put it like this

I always recomend "fire and forget" perrenial types like hasta and Lilley-of-the-valley.

Just me back-sliding into military vernacular. My way of saying lo maintinance, non invasive perrenials.

 

[Striker]

Could it be that the lady with the oak trees might be a little on the ignorant side when it comes to taking care of trees?A couple of years ago I didn't know that buring the roots would kill a tree. Now I try to talk people into installing tree wells when backfilling house foundations. ( we do grass seeding and and tree work) I'm not a tree hugger by any stretch of the imagination, but I have gained some appreciation for properly cared for trees . And yes I hate to see a tree that has been cut back to the big wood.

 

[che]

Could it be that the lady with the oak trees might be a little on the ignorant side when it comes to taking care of trees?

I think that's an accurate statement. I consider myself a gardener, but while I am really fascinated and in awe of so many trees here (sycamore, pawpaws, osage orange, red cedar, honey locust with dinosaur thorns, etc.)...I'll admit freely that I don't really understand how they tick. I'm picking up bits and pieces here even when mainly just observing the head butting that's going on. Most gardeners/homeowners don't have the opportunity to be lurking around a bunch of tree lovers and arborists letting it soak in at leisure.

There's a picture somewhere....kind of a mirrored silouette image of a tree. I get the feeling that to 'know trees' you have to kind of think like that. Feeling/seeing the whole unit. Good gardeners, those with green thumbs....do this naturally with their plants....but it's a step in a different direction to do this with trees.

I'll admit I have trouble with the thought of cutting out an oak for (what I feel is) no good reason. I guess its a case of priorities...or ill chosen words. I even have trouble cutting up dead horizontal osage orange trees though. We have a fence line full of old giants laying horizontally into the fields. Some are dead. I've been cutting these up for firewood(since I CAN, with my new saw )....but even then I have a bit of a wobble in my conscience. These trees were here at the turn of the century....being hedge, if I left them....they may be here until the NEXT century...a bit 'petrified', but intact.

Sorry to ramble, it's hot tonight.

JPS, thank-you for clearing that up. I understand now, and am glad I don't have to go clear out the lily-of-the-valley out back.

Che

 

[M.D. Vaden]

Based off some ideas in this thread, it could be concluded that anyone that has wood furniture in their house hates trees.

About gardening under trees.

One aspect of the issue may be adding a garden into an existing root zone, versus establishing a garden near a tree before the roots of the tree get there.

If the garden gets into the soil first, and the tree invades on the garden, then that is TREE DISEASE.

Shigo is great, and I have his books. But many people that commit tree idolatry can get one track minded.

Which has more right to live - an Oak, or a Rhododendron?

If a garden is put in with a root barrier, before tree roots enter that area, it can be much, much better than urban forestry where trees are planted along streets.

In a spacious yard, a garden with root barrier can leave far more room for roots than a tree in a planting strip near curb, sidewalk and street.

For the original post person, find a commercial source for a good tree root barrier if you can install it out a ways. And bamboo specialty stores carry root barriers.

The dripline you mentioned probably won't allow much root damage. There will be some roots out past that line, but it is probably insignificant and inconsequential.

The named Dr. Shigo also wrote that roots compartmentalize damage rapidly to isolate it.

Enjoy the gardening.

 

[John Paul Sanborn]

Originally posted by che
JPS, thank-you for clearing that up. I understand now, and am glad I don't have to go clear out the lily-of-the-valley out back.

If my Mom found out I had even concidered giving that advice, I would be persona non gratus for quite a while. No apple pie for me!

It is one of her favorite flowers. She wanted them for her wedding bouquette, but the florist in 1959 northern Wisconsin talke her out of it, by telling her how much it would cost to fly them in

 

[John Paul Sanborn]

Based off some ideas in this thread, it could be concluded that anyone that has wood furniture in their house hates trees.

is that hyperboly or solipsism?

One aspect of the issue may be adding a garden into an existing root zone, versus establishing a garden near a tree before the roots of the tree get there.

If the garden gets into the soil first, and the tree invades on the garden, then that is TREE DISEASE.

I guess it is what has more value. What we talk about is my referance to recurrant tilling of soil in the CRZ

Yes there are ways to get around it, but many may cause problems long term.

How long should that tree live? Does the property owner desire it to be able to live to something close to the species matureity?

If you mound soil on the trunk, you will get encircling roots that cause girdling decades down the road. Having the the FOR's covered can cause root to cross, which may lead to the fused rootplates that Bones and Smalley at Bartlet say indicate root rots.



Shigo is great, and I have his books. But many people that commit tree idolatry can get one track minded.

Which has more right to live - an Oak, or a Rhododendron?

which is more replaceable. Will your practices cause one or bith to have a graetly reduced Servicable Useful Life Expectancy?




The named Dr. Shigo also wrote that roots compartmentalize damage rapidly to isolate it.

This is refering to individual roots, not about the entire CRZ being disturbed on a regular basis several times a year.

Many people will alter their activites if they are properly informed. Having perennials in the CRZ and the annual/bulb beds out where the root density is sparser is better all around.