Here's where the brick border really takes shape!

How To Install A Brick Garden Border - Part II
The Edging Of Choice For Elite Gardens
by Jim Kohut, Staff Writer

To refresh, we’re going through the complete process of designing and installing a brick garden border. In the first part of this two-part series, we outlined the planning and design process, and looked at the logistics of ordering and bringing in the supplies. If you’ve just joined us or you’d like a refresher, click here to see Part I.

In this final installment of the series, we’re going to get down and dirty, first by preparing the site and then by installing the bricks. A few words about maintenance, and we’re done! So without further ado, here’s Part II...

Site Preparation

We begin the installation phase by first preparing the garden site. If this border is being installed in a new garden, then you’ll incorporate these preparations into the new garden installation process. If this is for an existing garden, then we have a few extra things to consider.

For one, the garden itself must be clean. That means free of mulch along the edges, accessible at the base for at least a couple of feet in, and it MUST be weed-free - if there is any grass already in the garden, then your efforts at keeping the lawn out of the garden, and in fact this entire project, will be in vain. If your garden is currently hosting a weed festival, dig the entire thing out and start fresh!

If there are any perennials or small shrubs in the first foot or so away from the edge, dig them out and set them aside in temporary planting locations or pots, and keep them well watered. This won’t be much of a challenge in spring or fall, but you’ll require some extra care and attention in the heat of summer - be sure to get as much of the roots out intact as you can, and keep them well watered! Likewise, the entire span of the border, including at least two feet out from the outside edge of the bricks, must be free and clear to allow for work, digging and access.

Now we’re going to transpose your design from paper onto the lawn. If your garden already has a clearly delineated edge which you trust to be true to your design intentions, then you can take a shortcut here. Take a sufficient length of garden hose, and using a rigid tape measure to set the gap, lay it along the outside (lawn) edge of the intended trench and exactly the width of the trench away from the existing garden’s edge (as a reminder, that’s equal to the width of the bricks plus 4” on either side). If the edge is relatively straight, you can set this gap every five feet or so, and if there are significant curves, take the measurements every foot or so. A little tweaking here and there, and when you’re done, the garden hose should follow the curves and look exactly like your plan on paper.

	Use a lawn edger to cut a clean edge into the lawn

If the garden edge isn’t well defined or if you’re creating a new edge, then I would recommend that you stake out the key definitions of the border using small wooden stakes. If the garden is going to be linear, you can stake only the turns in the edge and then tie a string from post to post to mark off the cut. If the garden is curved, then I would recommend staking off key points, with fewer stakes in straightaway runs and more in sharper curves, and then lay a garden hose along the outside of the stakes to get the flowing curves you desire. Remember, you’ll need to stake both the inside and the outside cuts of the trench.

Either way, your objective is to get a nice, clean and accurate demarcation of the places for you to cut into the lawn and the garden; along a string or along a garden hose will both work. Now take your lawn edger, and make a deep cut in the sod all along the string or hose, cleanly and continuously. You’re not trying to lift the sod, just cut it to give a sharp vertical edge.

Once that’s done, use your spade to dig out the sod in chunks, and on the garden side, to remove soil so as to fully carve out a square trench with the dimensions you have specified. On the lawn side, the cut should be vertical and precise, while on the garden side, it’s not quite as critical (nor as easy in softer soil). The depth and shape of the trench are very important. The floor of the trench should be as flat and level as possible, both to allow for a proper settling of the crushed rock base, and to ensure that you have a consistent depth of the base.

Installing The Bricks

Now we get to play with our newly delivered materials. After the trench has been excavated along the entire length of the garden, we must first protect it from intrusion by grass and weeds with a barrier of high-grade landscape fabric. Take a 3’ wide by however long roll of professional grade landscape fabric and run it all along the base of the trench and up the sides of both walls. Don’t worry if it extends up and over the edges; we’ll take care of that later. Scatter a few handfuls of crushed rock along the corners to hold it in place. The fabric will bunch up when rounding curves; this is perfectly natural.

Fill the trench with 3/4-down crushed rock

Next we fill it in with a base course of crushed rock. Get out your gravel spade and wheelbarrow, and haul in some crushed 3/4-down gravel. Use the spade or shovel to scoop it into the trench on top of the fabric, a little at a time, spreading it with a rake or some other convenient tool. Take care not to rip the fabric with your tools, or it will defeat their purpose! Pack the gravel as you go, using your feet and a good sturdy set of work boots. Try and keep it as level as possible, but don’t worry about precision right now. Fill and tamp a starter course all the way along, trying to visually approximate the correct depth.

So we now have a floor, but how do we ensure that we have the prescribed depth of crushed rock? And even more importantly, how do we ensure that the bricks are the proper seating height relative to the grade? Here’s the real trick to making this work. Take a flat 2x4 that’s a few inches longer than the width of the trench. Starting at the beginning of the trench, lay it perpendicular to the trench, so that it spans the trench and represents the average final grade across the trench. Be sure that it sits at a finished grade level on both ends rather than atop some temporary pile of displaced dirt.

Now take a yardstick which has been marked off with the proper depth, and check all along the course of the trench for the proper depth. Use the rake or a hand trowel to move the crushed rock around until the floor is both level and at the correct depth, constantly tamping and re-tamping to build up a very firm base. You can even ask your kids or neighbors to join in and jump around the bottom of the trench!

	Build a level base of the crushed tock on which the bricks will be seated

But here’s a catch. We’re actually going to set the base course a little higher than simply the depth of the trench minus the height of the blocks. The reason is, we don’t want the bricks to sit with their tops exactly level with the earth grade, but rather a little above. We want this for three reasons; one, this will make them a little more visible against the grass, which you’ll note rises a few inches above the soil when mowed; two, it’s better to be higher than lower, because nature will work against you to fill over any bricks that are lower than grade; and three, the gravel base will settle a little over time.

The ideal height of the tops of the bricks should be somewhere between 1/2” and 1” above grade, giving us a little leeway for error. Too high, and they’ll interfere with your lawnmower, probably in a nasty way! That’s why we had set aside a “spare inch” of gravel when we ordered it - we’ll use it to build up the base just a little higher than “spec”. So to sum up, the “floor” of the base course should be somewhere between 4-1/2” to 5” above the bottom of the trench, or the height of the bricks less 1/2” to 1” below final grade.

If you’ve been following me so far and doing everything reasonably correctly, you should now have a nice, flat course of well-packed gravel running along the bottom of the entire trench. You’ve checked along its entire length to be sure that it is precisely the correct depth below final grade. Finally, we’re ready to install the bricks themselves and finish off the project.

Look for a smooth surface to develop along the row

To do this, pick a starting point, and place your first brick squarely on the gravel base. Make sure it sits relatively level, visually speaking, to the grade. If there is a slope running parallel to the course, the brick should gently follow the slope, but I would suggest that for any slopes running perpendicular to (across) the trench, the brick should actually sit truly level along this axis; it just looks better. Use a level to help you achieve this.

Tamp the brick down firmly with the butt end of a small 2x6. It should be seated firmly in place, enough so that it doesn’t rock from side to side, and yet without digging itself into the gravel base. Keep a little pail of gravel handy beside you, so that you can add or remove gravel as necessary to level each stone. Once the first brick is firmly in place, continue on in one direction adding brick by brick, leveling each, and additionally comparing its lie to the preceding bricks. As you add bricks, you should see a smooth surface developing in the trench, and any deviations in the lies of individual bricks will become evident - go back and correct them as necessary. From time to time, use your long 2x4 to check the tops of the bricks against the grade; remember, they should be between 1/2” and 1” above the final grade.

If the ends of the course aren’t intended to meet by your design, then you’re done when you’re done. If this is a continuous border that meets back at the starting brick, the meeting should be smooth and level. But if for whatever reason the two ends don’t meet just quite right, address this by removing 2 or 3 bricks on either end and creating a smooth medium level in the base and refitting the bricks. Even if an adjustment is required, by spreading it out across 6-7 stones, it won’t be perceptible to the eye.

Last But Not Least...

Finally, we’re ready for the finishing touches. First, we’re going to fill in the gaps along each side and in between any of the bricks, and we’re going to do this using the crushed rock rather than soil. There’s two reasons for this - it facilitates proper drainage around the bricks, and it acts as a further disincentive for grass to try and grow into the border; even if it does, grass is much easier to pull from gravel than from soil. So gently scoop gravel into the sub-trenches along either side of the bricks and into any gaps in between, filling them to maybe 1/2” below grade. Tamp down using the 2x6 frequently - it should ideally be as well packed as the base gravel. It’s a little tougher to do this in between bricks, but do your best.

	Fill over the bricks, add the soil and don't forget the plants!

Now use a sharp utility knife to trim the exposed excess landscape fabric along either side of the trench to grade level or slightly above; cutting too low may allow grass roots to creep over top. Next, take some good quality garden soil, and sprinkle it over the top of the entire trench, including the bricks and the gravel in the sub-trenches and gaps, to a depth of about 1/4”. Use your hands or a soft broom to sweep the soil off the tops of the bricks evenly onto either side, bringing the soil to roughly level with the earth grade on either side, with the bricks sitting slightly above - don’t slope it. Gently wash the tops of the bricks and settle the soil on the sides and gaps using a light spray from a garden hose.

And that’s it - you’re done! Fill the garden gap back in with soil, replant any perennials or shrubs that you moved, and enjoy. As for maintenance, there’s almost none required - maybe just the odd pulling of a weed or some bold runners of grass that have dared to grow over the barrier and into the gravel in between the bricks. But you’ll find them very easy to pick out of the gravel, and they won’t be very persistent at all!

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