Great, thanks for the quick reply. It really reassures me.

I was mainly concerned with the cedar being able to take such heat, considering it thrives for winters. I live in Canada and summers get very hot and humid in July and August.

I guess I was just concerned about de-stablizing a very well-established tree, by changing something so "drastic" in its set-up.

The pear tree, on the other hand, doesn't get very much sun directly on its base, as it's very close to a fence, so only the base and leaves from 5 feet off the ground really do.

Should I put mulch around the bases, or can I simply leave 2-3 inches of dirt around them like I did?

Nothing against the base of the plant/tree - just leave the bare soil exposed.

And depending on what you mean by 'cedar' - a whole lot of non-cedar plants are referred to by that common name - it's very likely that only a very small portion of the root system is covered by the rock mulch, so doubtful that there is much "destabilization" or "drastic" changes going on at the base of the tree. Ditto with the pear. Roots on mature trees can extend out 2-3 times the height of the tree, often more.

I think the cedar is an Eastern Red Cedar. It's already at least 30 feet high (and my pear tree is about 20 feet high). They're both fantastic so I want to make sure to take good care of them :)

Just so you know........Eastern Red Cedar is actually Juniperus virginiana. Where 'cedar' factors into the equation is anybody's guess, as Junipers are not even in the same plant family as true cedars (Cedrus species). One of the many issues when using a common name in place of the correct botanical name :-)

Just my opinion but as the owner of half an acre of woodland I don't get the appeal of surrounding any of my mature trees with river rock. Seems unnecessary, unattractive and maybe unhealthy.

A 'woodland' can be very different in both character and plants than a cultivated garden. I agree mulching with rocks is probably not a great idea in a woodland setting - first, it's completely out of character and yes, it is unnecessary. Woodlands generally are not mulched at all unless by mother nature :-)

I don't personally favor rock mulches as they are difficult to maintain cleanly and they do not add anything to soil quality, which is one of my requirements of a good mulch. But many urban and semi-suburban gardens do feature them, especially in drier climates.

The attractiveness or aesthetic appeal of this is all in the eye of the beholder. I attended a lecture recently presented by Helen Dillon, a very well-known Irish gardener and garden designer and she showed photos of a large birch grove on her property that was entirely mulched with river rock - just the trees and rocks, with a few clumps of early spring bulbs, and the look was dramatic and stunning. How she attends to the volume of leaves these drop each season was not revealed in the discussion but since her garden is open to the public each year, I'd suspect a large team of hired gardeners attends to the clean up. Not something us mere mortals can always take advantage of :-)

gardengal - We actually have tons (literally) of stone on this property. We have boulders, flagstones & river rock - some was here but we took everything apart, bought more & rearranged. 2 neighbors gave us their unwanted flagstones. We have retaining walls, stone edging, accent boulders & stone walkways. We used river rock between some man-made concrete aggregate circles (that were here) to make a path. Path has a stone edging to contain it. Would be a full time job to keep the river rock "perfect". Spent a HUGE amount of time picking river rock out of dirt sorting it (throwing out ugly & broken pieces) & moving it to the path. We chip leaves to compost & mulch with it. I hate anything surrounding tree bases. Even in a suburban garden I wouldn't want rock mulch around a tree and gave irasupa my opinion. Wish the previous owners didn't dump so much river rock here. There are pics of my backyard fall color on the hosta forum (thinking about next year already) but with so many leaves u can't see much rock.

I actually really don't mind leaves and a little bit of dirt getting on top of the river rocks. Honestly, I don't find that unattractive or even annoying - as a matter of fact, I even like that ;) I find it to be more organic that way, otherwise it would be too "perfect" for my tastes.

My only concern was whether it was unhealthy for the trees, the heat it can potentially generate, etc. That being said, I've cleared a good 2 inches around both bases so I'll see how things look next year I guess.

We have a very natural look & it will never look "perfect" - which I don't mind either. Trees with basal flare (no volcano mulching) appeal to me the most and fit our setting.

Trees have a big impact on your home value - established tree canopy can even raise the value of your neighbors by 3-15 percent. The loss of tree canopy has a deleterious effect on home value, energy costs, and enjoyment.

That is important to understand, as rocking the base of trees creates several issues that can lead to tree loss. Rocks harm trees as they:

1) Compact soil, reducing important air flow around roots,

2) Inhibit the absorption of rainfall, which keeps roots cool and encourages deeper roots, and

3) Encourage heat around the roots, making trees less drought tolerant.

The strategy produces additional issues. Rock mulch amplifies heat islands (and therefore your electric bill) and increases run-off, which must be [strategically directed[(https://www.houzz.com/magazine/dry-riverbeds-solve-water-runoff-stsetivw-vs~1501884) to avoid property damage. Because the roots of rocked trees will search more shallowly, they also become more likely to damage property.

In LA, the drought causedirreparable harm to our tree canopy throughout the city. The natural challenges were amplified by landscape choices, including rocking trees and gravelscaping more broadly.

Healthier options include leaving the area natural or planting foliage native to the underscores of woodlands nearest you. Here in LA, great understory options include:

Sword fern and Island Alum Root

Island Alum Root · More Info

Canyon Prince

Canyon Prince · More Info

Hummingbird Sage

Magical Hummingbird Sage · More Info

Hope this helps! Best of luck to you.