Like a Flagstone Cowboy: Summer 2023 Project

I've been walking these paths so long, singin' the same old song

One of the things that has long annoyed me are the gravel paths we put between the perennial beds in the side yard many years ago. I had hoped they would be low maintenance, requiring minimal work to keep them clean and weed free. Boy, was I wrong. Between the moles pulling up soil from underneath, the raccoons and birds throwing mulch in from the sides, and seeds, leaves, and fir needles falling in from above, it has been nigh impossible to keep our gravel paths looking as pristine as they do in everyone else’s garden. Enough is enough. Time to try something new.

This, for example, is from last April and shows a semi-circular swath of gravel path next to one of the perennial beds. It’s a weedy, trashy mess that requires constant maintenance and I hate it. You can barely tell the difference between the perennial bed and the gravel. It all blurs together.

A few years ago, we installed pavers between the house and the raised beds to replace one of the problem areas. It’s DIY, so it undulates with the terrain. Moles and rodents have tunneled underneath, causing a little more uneveness. But, it’s easy to maintain and far better than what was there before. Just behind those raised beds is the basalt rock garden that runs the length of the side yard. It’s the weedy gravel path between the raised beds and the rock garden that became one of my top three summer projects for 2023.

Pavers installed a few years ago in the garden
May 2023 (L to R); sun garden (next to house), paver path, raised beds, gravel path (2023 project), rock garden, more gravel paths (future projects), and perennial beds in distance

Here’s a better view of the path from May 2023. I wanted something easier to install than pavers (digging in and leveling the crushed basalt base layer was a lot of work). I considered flagstone, but that became prohibitively expensive during the pandemic and would have required multiple trips to haul home from a store inconveniently located on the other side of town .

Weedy, gravel path in a garden
The object of my ire

L suggested using reusable concrete paver molds (here), but I didn’t want a repeating pattern and installation looked like a lot of work. The rectangular molds also wouldn’t fit easily around the uneven edges of the rock garden. After tootling around on the internet one day, I found this video by Uniquely Ursula showing how to make individual flagstone molds from vinyl blinds. The advantages were immediately apparent – no digging and no repeating pattern –  the molds are reusable, easy to reshape, and I could make the stones directly on top of the existing gravel path. I trialed the method with several types of concrete during fall 2022, before the weather started freezing. This was the result.

Trial concrete pavers made in fall 2022
First trial at bottom, last trial at top

After trying four different types of concrete, I was happy with the results and comfortable enough with the technique to try it on a larger scale next to the house. Quickrete 5000 gave the best results without too having too much exposed gravel. So, in the spring of 2023, I started on the gravel path next to the rock garden.

I know every crack in these dirty sidewalks of Broadway

I began work once the weather stopped freezing in May. Basic materials included a trowel, vertical blind louvers ($23 for a pack of 9), painters tape, scissors, metal stakes or pins, nitrile gloves, vegetable oil, cheap paint brushes, a bucket, Quikrete 5000 ($5.30 per 50 lb bag), Quikrete liquid concrete dye ($10, charcoal and brown), and Behr low-lustre concrete sealer ($38/gallon). I used 3.5 inch wide blinds, cut them lengthwise into two 1.75″ wide strips, and then cut them again crosswise to get different lengths. I then bent the ends of each strip into a loop and taped it together to make an individual concrete mold. Using this process, I was able to make 4 to 6 molds from each blind.

I wanted my flagstones to be more angular, so I crimped the plastic at several points around the perimeter. If I bent the plastic too far or if the temperature was too cold, it would crack and break. So, I had to be careful. However, the breaks were reparable with more tape. I’ve also always wanted to try making my own fossil impressions, so I thought this would be a good opportunity to see what would happen if I tried pressing leaves into the wet concrete. We’ll get to that part in a bit.

Placing DIY plastic molds to make concrete flagstone
Test mold with concrete (top) and two empty molds (bottom)

Once I had a set of about 12 molds ready, I used the trowel to roughly level the area where I wanted the new flagstones to go. I then painted the inner surface of each mold with vegetable oil (to make removing the mold easier once the concrete sets) and pinned them into place next to each other with thick metal pins. The pins also helped keep each mold in the specific shapes that I wanted them to be in. I then either poured or moved the prepared concrete into one of the molds by hand.

Plastic molds set up and concrete ready to pour for DIY flagstones
The Flagstone Cowboy mixing concrete
Using nitrile gloves to transfer wet concrete to the plastic mold to make DIY flagstone
Flagstone Cowboy in action

The concrete needs to be pretty wet and loose, with a light sheen of free water on top. If it is too dry, it sets too fast and you end up with a lot of exposed gravel.

After evenly spreading and smoothing the wet concrete throughout the mold (about 3/4 to 1.5 inches thick), I drip dilute concrete dye (about 50% with water) onto the wet surface and spread it over the top layer by hand. I varied the amount and placement of each color to achieve a more natural appearance, preferring charcoal over brown to match the basalt in the rock garden.

Spreading the wet concrete through a DIY plastic flagstone mold
Spreading the concrete in the mold
Dripping black concrete dye onto wet concrete in a DIY plastic flagstone mold
Dripping the charcoal dye
Dripping brown concrete dye onto wet concrete in a DIY plastic flagstone mold
Only a little brown dye
Mixing concrete dye into the surface of wet concrete
Spreading the charcoal dye
Mixing concrete dye into the surface of wet concrete
Bringing in a little brown

After the entire surface is covered in dye, I place the leaves to make the fossil impressions. The bottom of the leaf has more texture, so that side goes down. Then, pat into place. Any pins used to hold the molds in place can come out at this point. Smooth over any holes.

Placing a leaf into wet concrete to make a fossil impression
Alder leaf, bottom side down
Patting the dyed concrete down in the concrete flagstone mold
Pat, pat, pat

After completing this step, I move on to the next mold in the lineup and repeat the process until I am done with the bag of concrete. Once the concrete has dried a little bit, I texturize the surface with my finger to roughen up the surface and make the stones look more natural. This step depends a lot on the temperature outside. Cooler temperatures significantly lengthen the amount of time I need to wait (sometimes overnight), while hotter, drier conditions shortened it to as little as 15 to 30 minutes after pressing in the leaves.

Texturizing the surface of the concrete after it has hardened for an hour.
Texturizing to make the surface look more like real flagstone

After texturizing, the concrete should be set enough to begin removing the molds by hand, working them gently up and down while moving around the perimeter. The concrete at this stage should still be moist, but flexible and firm, like soft artist’s clay. This allows you to patch any bits that accidentally crack off with a wet fingertip. This is also a good point in time to pat down the edges. Wet concrete rides up the sides of the plastic, creating a sharp lip if it isn’t smoothed down soon after the mold is removed. After all of that is done, I clean up by washing any concrete residue from my plastic molds, tools, and bucket.

Setting the molds in place for the next set of concrete flagstones
Placing the molds before adding concrete
Leaves pressed into wet concrete flagstone to make fossils
Time to remove the molds

I was sort of dumb/impatient and didn’t rewatch the instructional video when I began making flagstones back in May. As a consequence, I waited waaaaay too long to remove the molds after the concrete had set. This resulted in a lot of sharp ridges and cracking around the perimeter of each stone, exposing the ugly gray concrete underneath. I continued doing things this way for a while until L recommended coating the mold with motor oil. This made the removal much easier, but also left a long-lasting oily residue on everything that I felt uncomfortable washing into the soil. Luckily, vegetable oil worked just as well, was safer, and the residue disappeared within a day or two. And, after finally rewatching the video, I learned that I needed to remove the molds much earlier in the process while it was still somewhat wet and pliable.

Each bag of concrete filled about 9 to 11 molds, depending on size. After completing a set of stones (1 bag), I cover them with a tarp (per the bag’s instructions) to keep the concrete from drying out too much in hot, dry weather. This promotes curing and prevents cracking and brittleness. I also sprayed the concrete down with water every morning and evening for a few days to make sure it stayed moist.

Where hustle's the name of the game and nice guys get washed away like snow in the rain

Here, I was about a quarter of the way done with the path – looking west towards the orchard garden. In order to finish the project by fall, I tried to do two bags each weekend – one on Saturday and one on Sunday. It was a busy, difficult summer, so things didn’t always go according to schedule.

There's been a load of compromising on the road to my horizon

The next photo shows what happened when I waited too long to remove the molds. There is a lighter-colored, rough edge around the perimeter of each stone where the top layer of concrete flaked off during mold removal. I tried painting on a dilute suspension of black dye to cover it up, but that didn’t work. So, I stopped trying and decided to see if the edges would weather and become more natural looking over time on their own.

Another issue was that some stones ended up at different heights. It was hard to tell whether the stones were level with each other because the surface of each stone was below the lip of the mold. It would have been easier if the the molds had been shorter and the concrete had come all the way to top. There is also a slight slope along the length of the path that made it difficult to keep the stones level. I eyeballed things as best as I could, but things didn’t always work out. I will probably have to reset some of the worst offenders come spring.

Uneven heights in DIY flagstone
Stones at different heights with exposed edges. I painted the edge of the tallest stone, but it turned out too black.

But I'm gonna be where the lights are shinin' on me

There is also a slight difference in appearance between the stones I made in May versus those in September. My process of making the stones evolved over time and there was always batch to batch variability. However, natural flagstone varies in appearance too, so I think that worked out in my favor. I am also extremely pleased with how well some of the fossil impressions turned out.

Lady's mantle and fern fossil impressions in DIY concrete flagstone
Lady's mantle (Alchemilla mollis)
Fern frond fossil impressions in DIY concrete flagstone
Bracken fern (Pteridium aquilinum)
Sword fern and Polygonum leaf impressions in DIY concrete flagstone
Sword fern (Polystichum munitum) and Polygonum
Devils club leaf impressions in DIY concrete flagstone
Devil's club (Oplopanax horridus)

Flowers worked too.

Common oxeye daisy flower fossil impression in DIY concrete flagstone
Fossilized oxeye daisy (Leucanthemum vulgare)

The flagstones looked dull and gray once they dried out, so the next step was to let them cure for 30 days and then apply a concrete sealer to give them a deeper, more lustrous look. 

Unsealed concrete flagstone has a dull, gray appearance
Before the sealer was applied

I also needed to wait for the leaves to peel/wear off in the older sections first. Here’s a long view looking east sometime in mid-July, 2023. Most of the leaves dried up and were easy to remove. Others have remained firmly embedded, even through winter.

Like a Flagstone Cowboy

I started applying sealer in late September. You can see how shiny it is on the east end of the path. I used two coats.

This is as about as far as I got with the sealer before the rains halted progress in mid-October. Even with all the imperfections, I like how this project turned out.

A few photos from this year in early February. It looks like real flagstone from this height.

There are weeds already coming up in the cracks, but far fewer than in the gravel path off to the right of the rock garden. This should be easier to keep clean with our electric leafblower too.

It is interesting that some of the impressions I made at the end of last summer turned white. I wonder if the heat leached out salts from the leaves that then reacted with the concrete? Whatever this substance is, it is hard and crusty, and impossible to scrub out without destroying the impression.

I’ll leave you with a parting shot from October, looking west towards the orchard garden from underneath a manzanita (Arctostaphylos manzanita).

Recap

  1. Prepare surface, making sure it is somewhat level.
  2. Make molds, cutting plastic blinds to the width and length that you want, and then taping the ends together to make a loop. Bend to shape.
  3. Coat inner surface of each mold with vegetable oil using a cheap paintbrush.
  4. Pin molds into place.
  5. Prepare concrete to be fairly wet and loose.
  6. Pour concrete into one of the molds, smoothing into place at least 3/4 inch thick.
  7. Drip cement dye onto surface and spread to cover.
  8. Press in leaves.
  9. Repeat steps 6 – 8 for each successive mold until 1 bag of concrete is used up.
  10. Once concrete has set to the consistency of artist’s clay, roughen surface with finger and remove mold. Patch any cracks and smooth edges with a wet fingertip.
  11. Clean up by washing off residual concrete from the molds, buckets, and tools with water.
  12. Let stones cure per instructions on bag.
  13. Coat with concrete sealer once curing is complete.
Note: Headings for today’s post adapted from Glen Campbell’s 1975 hit song “Like a Rhinestone Cowboy’.
 
Linnaeus, the super cat, finally gets to take his cone off. Paws healed from being burnt on wood stove.
Oh, and look who finally got to take his cone off! All (mostly) healed!

This Post Has 18 Comments

  1. tracy

    Applause, standing ovation! I really love what you’ve done, and that was some work you put in. I can only imagine how satisfying it is to walk on your path. Good Job, and yay for kitty feeling better/healing.

    1. Botanica Chaotica

      Thank you tracy! I am definitely satisfied with how it turned out after all that effort.

  2. S.

    That’s fabulous! Looks great.

  3. Jane / MulchMaid

    Impressive! I like the freeform shapes and the final look after all your color and finish work. And thanks for admitting it didn’t all go completely to plan; I appreciate a humanized DIY far more than a perfect one.

    1. Botanica Chaotica

      Thanks Jane. Heh, nothing I do ever goes completely to plan. And, as a person with perfectionist tendencies, I am learning that even when I try to achieve perfection, there is always a flaw. I am lucky to have a country garden where rustic goes well with the aesthetic and perfection would look out of place.

  4. @perennialtherapy

    Well done. This is really amazing. The foliage impressions were a great touch! Thanks for sharing.

    1. Botanica Chaotica

      You are welcome. I had such fun doing this project. I’ve been wanting to make leaf impressions for a long time. It’s satisfying that I finally found a way to do so and incorporate the result into the garden.

  5. Tamara - Chickadee Gardens

    Oh my gawd, that’s incredible! What a project and thank you for spelling it out, step by step, for those of us who may use this in the future. It looks amazing and I imagine as it weathers naturally will have smoother edges and be more uniform, though the variations make it interesting to me. Great job, very impressed, Mr. Rhinestone. Looks fabulous.

    1. Botanica Chaotica

      Thank you Tamara! Yes, I think you are right, everything will weather and look more natural over time. I’m looking forward to having one less path to weed this year.

  6. danger garden

    Wow, that’s fantastic and so much work. You’ll always be the Flagstone Cowboy in my eyes.

    1. Botanica Chaotica

      And, yet somehow, it seemed like far less work than putting in pavers. I need to get a real cowboy hat and boots now.

  7. Kris P

    That’s impressive, Jerry! It looks great. I love the leaf impressions. It was clearly a LOT of work but I”m sure you’ll find the investment of time worthwhile. My garden has cement block paving that came with the garden, flagstones my husband and I laid to separate beds after we removed all the lawn, and gravel we dug up from parts of the garden and used to cover the ground surrounding our raised planters in the cutting garden and a path through the dry garden. (Our neighborhood was a rock quarry in the 1940s and we made a lot of odd discoveries after moving in.) Weeds are a regular problem throughout but the block paving is by far the easiest to maintains.

    1. Botanica Chaotica

      Yep, that is what I am betting too – paving will be the easiest and quickest to maintain. I am hoping that will free up more time for me to focus on something else more rewarding in the garden, like working on my projects for 2024!

  8. Chavli

    Joining the chorus of adulations, this is indeed a very impressive DYI… gorgeous and I suppose most gratifying results. I particularly loved the leaf impressions: I could possibly commit to making a (single) decorative stepping stone using your method. I’m partial to the fern leaf and “fossilized” daisy.
    It’s nice to see a more panoramic view of your garden as well.

    1. Botanica Chaotica

      Some of those impressions turned out amazingly well. There is one of a bread poppy leaf that has every curve beautifully captured that is a favorite. But, even some of the crustier ones that didn’t turn out so well have charm. I’ve been thinking I should do an overview of all the different garden areas of the yard. It just takes some planning that I haven’t had time to do yet.

  9. hb

    That’s very impressive indeed! Looks like real stone, and it must be good to walk on, too. Congratulations on a job well done.

    1. Botanica Chaotica

      They turned out better than I had hoped. It’s nice to have them done!

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