Limestone Raised Bed

Planted!

 

I constructed this limestone raised bed by myself with no prior experience with stone masonry! It’s easier than you would think.

I haven’t seen any DIY instructions or blog posts for a raised limestone bed like this one so I followed instructions from various places, used some common sense, advice from my stone mason brother-in-law (who unfortunately lives too far away to help), and figured it out.

Location - BeforeStep 1. Figure out what size you want your bed, then identify the stone you want to use and do a little math to figure out how many stones you’ll need to make one row. I was aiming for a 4′ x 8′ bed, but I didn’t want to have to cut a lot of stones.  I also didn’t want to meticulously measure every stone before I bought them. They were not all the same length which presented some challenges. Since the stones I bought were (mostly) 14″ long, I ended up with a bed approximately 3.5′ x 7.5′.

 

Estimate

Step 2. Buying your stones. Once you’ve figured out how many you’ll need you have two options. You can buy them by weight from a local shop that sells stone, mulch, and media in bulk for landscapers. It’s much cheaper to buy by weight, but it may be more challenging to figure out how much you need that way. Home Depot tells you how much each stone approximately weighs so you can visit them, figure out how much in weight you would need, add a little extra just in case, and then go to your landscaping shop – assuming the stones are the same size approximately. I ended up buying them from Home Depot because I didn’t know that before hand and didn’t have time to make an extra trip. I ended up paying more to purchase per number of stones. (Qty. 42)

 

Estimate LocationStep 3 (optional) Lay out the bottom layer of stones on the ground approximately where you want them to be just to double check that you’re happy with the location. It’s more work, but you can make sure you aren’t forgetting something important. You can also walk around the bed to make sure you are leaving enough room on all sides. Arguably, with a small bed, you don’t have to leave a walk space on all four sides, but we tend to do a lot of fence repair and I wanted to make sure I had access to it and it’s much easier to reach everything with all sides available. I left a 2′ space between the raised bed and the fence.

 

Staking

Step 4. Stake the four corners of your raised bed area and tie string to create the shape of the area so you can begin to prepare the area. If you add diagonal strings and measure them, you can make sure your rectangle is square if both diagonals are the same length.

 

 

 

 

 

 

ClearedStep 5. Clear the area for your bed. Remove any grass, weeds, and dig down to 2-3″ below where you plan to lay your first stone. I made sure to remove enough area for the stones in a border shape, but I didn’t remove everything in the center of the bed down to the same level.

 

Step 6. Level the ground where the stones will be laid. My yard has a pretty good slope so I had to dig out quite a bit at the top of the bed and only just removed the sod at the bottom.

 

 

 

LevelStep 7. Lay out your stones. I went ahead and laid the stones in the ground and made sure they were level side to side and front to back at this point. I also added the second row and then I numbered the stones with sidewalk chalk so that I could put them back the same way. I also marked the last stones on each row that I was going to have to cut to fit.

 

Pea Gravel

 

 

Step 8. After setting aside the numbered stones, pour in 2-3″ of pea gravel and tamp it down with a tamper. I borrowed one from my neighbors and saved $25!

 

 

 

 

 

 

Saw the stonesStep 9. Cut the stones where you marked them. This is surprisingly easy. Limestone cuts easier than wood! I just used a simple hand saw and had a running water hose with a trickle of water to create a bit of a wet saw.

 

 

 

 

Step 10. Select your mortar. I’ll be honest. I was completely freaked out by this step having never worked with concrete before. One thing that make it tricky was I wanted the mortar/grout to be white, rather than grey because I didn’t want an obvious contrast with the light colored stone (which sort of happened anyway, but it looks fine so whatever). I also didn’t want to have to mix any sand myself, just a simple ‘just add water’ type. I had to speak with several hardware store employees before finding what I needed.  I ended up buying White Masonry Cement by the Alamo Cement Co. at Home Depot which ended up working very well after a bit of practice.

Step 11. Mixing the mortar. I highly recommending mixing your mortar in small batches. Since I have small kids and unpredictable amounts of time with which to work, I mixed batches that were only big enough to mortar about three or four stones at a time. It was a little bit frustrating to go so slowly and have to wash out my bucket and start over so many times, but it was worth not mixing up a huge batch that would harden or dry out before I could finish. It took a bit of searching, but I finally found one page that gave a ‘recipe’ for mixing the mortar. Use a ratio of 2 parts mortar to 1 part water and mix well. When mixed, you should be able to scoop a bit onto your trowel and it won’t drip off when you turn it sideways.

Waiting

Step 12. Apply mortar. This was my first experience with mortar and I can only offer my limited experience with how to apply. For the bottom row, I just glopped the mortar down in the spaces between the stones trying to fill them up. If you’re going to get mortar everywhere, try to aim the mess to the inside of the bed that will eventually be filled (and hidden). I would also add a bit more on the four inside corners to make them a bit stronger. Since I was working in small batches, I would do three to four stones and then go make another bath of mortar. After letting the mortar set for about 10 minutes, I would go back along my previous work and smooth out the mortar with my fingers removing any excess mortar. It reminded me of working with clay and I would just try and smooth it down so that it would harden without any rough edges. As you’re going, be sure to get up and go look down the length of the row to make sure you are setting them straight and continue leveling as you go. You can use a bit of mortar to make any adjustments. Adding the second row is a bit more tricky. You have to work fairly quickly to slap the mortar on the first row and then set your next stone. If you wait too long, the mortar will already begin to dry out and you won’t be able to set your stone properly. This is why there are no pictures of this part of the process. I can assure you it doesn’t look pretty while you are doing it. Don’t sweat it.

I did have a bit of trouble with one section/batch of mortar where it started getting really crumbly and I didn’t think it was going to set up, but I was wrong, it just needed time. However, if it’s starting to crumble while you’re applying it, you’ll have to make a new batch. I did end up having to re-do a section of one row the following day because I had loosened it a bit trying to see if it was set. I used metal spackle tools to scrape off the old mortar. They also worked pretty good to apply the mortar as well. You don’t need to buy the expensive tools either. Get the cheapest ones you can find.

Don’t forget to go back and smooth down your mortar after you’ve let it set for a little while. If you wait until the next day, it will be too hard to smooth down.

Step 13. Wait. I waited a few days to let the mortar set up and harden before continuing.

Weed Barrier

 

 

 

Step 14 (optional). Add a layer of weed barrier. Our yard is full of bermuda grass and I knew that if I didn’t put down a layer of weed barrier, it would only be a matter of time before my raised bed was full of it. It ran up the sides of the bed as well about 6-8″.

 

 

 

 

Fill it up!Step 15. Add media. It’s up to you how you want to proceed. I had originally planned to try lasagna gardening with this bed, but ran out of time. I had seedlings that needed to be planted so I got a 1/2 cubic yard of a mix of garden soil made with composts, soil, composted rice hulls, and decomposed granite from a local nursery for $24.50. The price was significantly less than buying bags and using a shovel and wheelbarrow was easier than I thought it would be. I added 4 cups of Espoma PT20 20-Pound Plant-Tone Organic Plant Food to it as well.

 

Finished Raised Bed

 

 

 

 

Step 16. Plant!!!