Choosing Your Garden GravelSeptember 23, 2016
There are many garden gravels to choose from and many applications for gravel in the garden. Making a poor material selection can be both dangerous and ugly. Fortunately, with proper planning and installation, gravel can be a wonderful and relatively inexpensive hardscape material.
Why do you need gravel?
Trying to suppress weeds in a planting area? Creating a walkway, patio or driveway? Creating a decorative dry stream bed? Or something else?
A common challenge is simply selecting the right gravel for the right application.
If you’ve ever visited a stone yard, you’ve probably fallen in love with many colorful gravels on display. The problem with many of these gravels is their shape. While using round stones in mixed sizes is ideal for creating a decorative dry stream bed, these stones simply do not compact into a safe, hard surface for pathways and patios. Soft mixes of pea gravel, round pebbles or even semi-angular pebbles with tumbled edges will turn into ankle-twisting walkways that neither a wheelchair nor a wheelbarrow can traverse.
Instead, opt for something a little less showy for your walkways. Truly angular rock with lots of fines will compact into a solid path that also drains. These gravels are usually referred to by the size of the largest partical in the mix: 5/8s-minus or 1/4″ minus are two popular options for walking paths.
These are also used as an ideal base material for permeable stone patios and paths. In fact, in most applications they work better than sand, which is also a bunch of tiny, round particles that don’t compact well.
What about gravel to suppress weeds?
Many believe that covering a planting area with decorative rock will keep weeds from growing. But, weeds are tough and will easily push right through a permeable pebble or gravel layer.
Too, a thick layer of stone placed over a planting bed may raise temperatures enough to burn tender plant roots below. While flame weeding over stone may be possible in some situations, running a flame weeder around plants may burn and even kill your garden.
Should I put landscape fabric under my gravel?
Covering the earth with landscape fabric and topping it with gravel path or patio is just asking for a twisted ankle or worse injury. That fabric is slippery. Stone on top just gets more slippery. Angular gravel that should compact into a safer walking layer, won’t tighten up over fabric. And round pebbles will roll worse than ever on that slick surface. Plus, in the wet season, water may end up pooling or sheeting in runoff streams when it can’t readily pass through fabric to the soil below.
Adding a layer (or overlapping layers) of landscape fabric between your garden bed soil and a topping layer of gravel isn’t going to do you any weeding favors in the long run. That fabric layer will eventually pop up through the stone and look like trash flags on your garden floor. And, the fabric will inhibit moisture from flowing into the soil, which can stunt or kill your plants and the living eco-system within the soil itself. Plant roots will readily grow between overlapping layers of any fabric as they attempt to find access to moisture above ground. As they weave their way through the layers, roots may become kinked and otherwise caught in a messy entanglement that’s hard to later remedy.
So, do it right in the first place. Skip the fabric. Avoid the lure of colorful round pebbles. Install functional paths that will weather the test of time and mulches that will encourage rather than suppress the complex life beneath your feet.