Interlock and River Rock: Pros and Cons

Interlocked sidewalks or driveways/laneways and river rock instead of lawns may look nice and tidy until the weeds move in. And they will try, you just have to stay on top of them for a winning look.

Weeds are inevitable as their seeds blow around in the wind, lodging themselves in the cracks between the interlocked stones or river rock. They can settle into the tiniest of cracks and then sprout to become a huge mess. Don’t disparage the contractor that you paid to make your yard look nice, it is not (generally) their fault. Weeds and wind are facts of nature.

Polymer Sand Between Interlock

Most landscapers use polymer sand, AKA hardscape, jointing, or paver sand, a mixture of fine grains of sand and bonding agents. These products fill in the cracks between the interlock stones of sidewalks, patios, and driveways. The benefits are stability (the stones don’t shift), weed control, and even insect control.

The problem is, even when applied properly (there is a specific method of applying polymer sand) weed seeds will still congregate on top.

The most recent look in interlock involves larger slabs of stone, meaning fewer cracks for weed seeds to invade and you to keep clean. That’s a move in the right direction.

Landscape Fabric Under River Rock

Landscape fabric is (should be) used under river rock when it replaces lawns to help keep weeds from poking through from underneath. Some aggressive weeds still do manage to get through the barrier though. As mentioned above, nothing prevents weed seeds from blowing from above and settling between the rocks.

Landscape fabric can be purchased in (very) large rolls or smaller, more manageable rolls. Regardless of the roll size, choose the heavy-duty kind.

Unstable Footing

One of my biggest complaints about landscaping with river rock is the instability of the rock surface for anyone walking on it. That would be me working in a client’s garden. Even though I always wear stable shoes, I still find the rocks unstable to walk on so worry about twisted ankles.

I do find the smaller stones more stable than the larger ones.

Interlock and River Rock, pros and cons

Vinegar to Kill and Deter Weeds in Interlock or River Rock

Vinegar, and not just regular vinegar but the extra strength “cleaning” vinegar, works well to kill any weeds that do manage to sprout between the cracks of your interlock or stones/rocks. It also deters new weeds from sprouting. I put the vinegar in a large pressurized sprayer to make large applications easier.

Interlock and River Rock, weeds

Weed Torches to Keep Interlock and River Rock Tidy

Another method of removing weeds that have sprouted between the cracks of your walkways or patios or your river rock is a propane-powered weed torch. I have yet to try one but have heard only good reviews on them.

Conclusions

I don’t mean to discourage anyone from replacing their old, outdated walkways with much prettier interlock or their lawns with river rock, but want people to be aware these types of landscaping still require work. Lots of work.

photo credit: Pexels free photos

Patio Restoration

For many hours this past month, one of my large projects in my landscaping business was a patio restoration in one of my favourite Kanata gardens. ┬áThe extensive patio and walkways were constructed approximately 7 years ago using an intricate and beautiful combination of flagstone as well as interlocking rectangular and square pavers, surrounding an exquisite custom-built home in one of Kanata’s most desirable neighbourhoods.

My job was to restore the patio and walkways to their former glory, as they had become weed, moss, and ant-infested over the years.  This patio restoration was quite a massive undertaking for me, as I had no previous experience with this type of landscaping, work as a one-woman team, and generally specialize in garden design and maintenance.

I consulted with a few friends that have built and maintained patios to find out the best way to get rid of the unwanted moss and weeds, then replace them with a polymer sand product to discourage their return.  Although I do realize that moss between flagstones can offer a desirable and natural look in some gardens, I agreed with the homeowner that this was not suitable for this magnificent home as it appeared neglected and unappealing, rather than intentional, yet natural.

This home is built in a natural woodland setting, so the first step of the patio restoration was to sweep the walkways and patios clean of leaves, dirt, twigs, deer and rabbit poop etc.  I then enlisted the help of my 16-year-old son to power wash the stones,  especially the cracks in between the stones, to remove the clumps of moss and weeds.  I am not sure what was originally used between these stones as a sealant, but whatever it was, there was not much of it left in the cracks, so the weeds,  moss, and ants had clearly taken over.

patio restoration

Once the patio and walkways were completely cleaned, I had to wait for a few consecutive sunny days with no chance of rain.  Last summer, this would not have been a problem, but this summer it was much more challenging.  The instructions for the polymer sand indicate that the area to be sealed must be completely clean and dry before sweeping the polymer sand between the cracks.  Then the area must be gently wet with a hose several times to complete the sealing process.  It must then dry for at least 24 hours without rain, excessive heat or cold, or foot traffic, to ensure a proper and successful seal.

The end result of this patio restoration is beautiful though, hopefully, long-lasting and well worth the effort.  The greenish tinge on the patio beneath the swing in this picture is not moss, just a reflection of the lush greenery in the damp patio stones after the completion of the project…

patio restoration