# Gravel Boulevard



## Montanamamma (Aug 29, 2018)

We had our boulevard excavated and plan to lay landscape fabric then decorative gravel down. There will be a few small beds with hardy, native drought tolerant plants here and there, plus a few pre-existing trees. I plan to spread fill dirt evenly on top of the uneven existing soil to bring the soil up to the desired level to allow space for 3-4 inches of gravel to be flush and contained with the surrounding curb and sidewalk. 
My question:
I have been told by several people that I don't need the fill dirt. Just get more gravel and spread that evenly. Gravel is more expensive than dirt and in my opinion, will shift around on uneven ground, and end up looking crappy. Also, in 10 or so years, we may need to replace the gravel if it is full of debris and harboring a weed patch. I don't want to remove 6 inches of gravel! What is the correct way to do this?
Thanks! MM


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## ken-n-nancy (Jul 25, 2017)

A few thoughts from my personal experience with gravel / crushed rock along the roadside:

The bigger the rocks and the deeper the rock layer, the less weeds will grow in the rocks. The spaces between the rocks will tend to become filled up with stuff over time, such as sand (is that spread on your road by the town?), dirt, decaying biomatter (leaves, grass clippings, twigs, pine needles, etc.) and the like.

Bigger rocks will have "bigger gaps" between them, which will allow the above items to percolate down into the bottom of the rock layer, instead of building up on the surface where they're start to be soil in which weeds can germinate.

Similarly, a "deeper layer" will allow the "other stuff" to percolate down to the bottom of the rock layer, where weed seeds won't be able to grow, even if they germinate, as it will be dark down there.

So, in general, I would recommend the largest rocks and the deepest layer that you can. Personally, for something like the area between the sidewalk and the road (is that what a "boulevard" is in your neck of the woods?) I'd want to use a rock size of maybe 2-3" and about 6-8" depth as minimums. More would be better.

You want to make sure that your gravel doesn't include "fines" in it - this is small aggregate all the way down to sand-sized grains. Any fines in your crushed rock are basically just a head start on getting weeds in your rock bed.

Personally, my experience is that I would only use a crushed rock mix that has stones of at least 1.5" in size (meaning that they don't fit through a 1.5" screen) and have been "washed" so that they don't include significant "fines." Otherwise, the rock bed will become an ongoing weed prevention problem.

From my perspective, regular gravel is to be avoided for areas intending to remain weed-free, as it includes fines, and will grow weeds. This is what would be used for a typical gravel driveway or gravel road, which will tend to develop weeds in it over time unless receiving heavy traffic. It has the advantage of packing down great (to carry vehicles without shifting at all) but will support weed germination, rooting, and growth.

"Decorative gravel" isn't a lot better, from my perspective, as it will typically be approximately 3/8" or 1/2" crushed stone, which may be washed to remove stone dust and fines, but doesn't have very large gaps in it. This will look awesome the first year, or maybe even a couple years, but by years 3-5 will be starting to clog up with sediment and grow weeds and have you wishing you had done something different. I've "Been there, done that," so your description of what you are putting down as "decorative gravel" gives me the chills, as a few years ago I ended up replacing a roadside border that was made up of what it sounds like you're going to install because keeping it looking good was too much of a maintenance headache.

"Decorative gravel" also has the problem of being hard (impossible?) to pick out of the lawn when some inevitably gets there, whether from a snowplow, kids playing, etc. (On the other hand, 2" stones aren't so hard to find and pluck out of the lawn...)

If you're sold on going with "decorative gravel" I'd encourage a depth of more like 5-6" instead of 3-4" if the cost difference is manageable. I would definitely not add any fill dirt to a decorative gravel bed unless the initial depth is about 10-12".

What is the edge around the boulevard? Is it concrete on all sides? Concrete sidewalk on one side? Concrete curb on the other? Asphalt? Dirt? Pavers? Granite Block? Dirt lawn? The reason I ask is that crushed rock / gravel will want to "escape" from the rock/gravel area unless the rock/gravel height is a little bit lower than the surrounding border. The ability of the border edge to sustain wear will depend upon what it is and what traffic is expected.

Does the rock/gravel need to sustain parked cars? Kid's bicycles? An occasional commercial vehicle? (UPS truck? Septic truck?) These may affect the choice of the border edge and rock type, too.

In any case, good luck with the project -- sounds like it will be an improvement and you seem to have an aesthetic vision of what you want!


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