|How To Install A Brick Garden Border - Part I|
|The Edging Of Choice For Elite Gardens|
|James Kohut, Staff Writer|
If you are a homeowner and have a lawn and one or more gardens, then you know it's a constant challenge to keep the grass out of the garden. It will try everything in its power to get into the garden, whereupon it will wreak total havoc on even the most diligent gardener.
Other than by a regular and frequent maintenance program, the kind which most of us have neither the time nor the patience to perform, the key to solving this nasty situation is to have an effective boundary between the lawn and the garden. And when it comes to edgings, none is quite as attractive and effective as a brick border. It looks fantastic when properly designed into the landscape composition, and is amazingly efficient at keeping the grass away from the garden. Even when the odd runner of grass does succeed in getting between the bricks, it's a two second pull away from the weed pile - maintenance has never been so easy!
Here at Northscaping, we've had numerous requests for instructions on how to design and install these magnificent low-maintenance brick borders. Well, folks, here it is - Part 1 of a two-part series with everything you need to know about bringing one of these into your landscape!
As an opening comment on the scope of this project, we're going to cover brick edging where the garden is at approximately the same level as the lawn when viewed across the bricks. As such, the bricks are used as a finishing edge only rather than for a structural purpose, for example in a retaining wall application where they have to actually provide support for the garden soil. Structural walls have further considerations which we're not going to cover in this article - you'll find a separate article in the Info Zone on how to build a retaining wall planter if this is what you're after.
Let's start things off by painting ourselves a picture of what this will look like when we're done. On the surface, all we'll see is the garden, the lawn, and a level train of ornamental bricks cleanly separating the two. Underneath, the bricks are actually sitting atop a base course of crushed rock inside of a wide and deep trench. The crushed rock provides structural support for the bricks, gives us a level surface to work on, assists with drainage of water away from the bricks and resists frost heave in winter.
The process is pretty straightforward. As with any landscaping project, we'll start by planning the project long before a spade ever hits the ground. We need to derive a final design, which can either be on paper (recommended) or done right on the site (for smaller projects). Once we have a design, we'll plan the logistics of the project and the worksite, and then begin preparing the site for installation. We then install the base and the bricks, apply some finishing touches, and voila - we're done!
Planning And Design
So you want to install an attractive and low-maintenance brick edging to separate your lawn from your garden. This means you either have an existing garden, or you're building a new garden and will install the edging as a part of the overall garden installation. The process is quite similar in both cases.
All good projects start with a design. We can either create a design on paper which we'll then transpose onto the garden, which is my definite preference, or we can develop the design right on the site itself. I'd only recommend the latter approach for the smallest and simplest of projects. For the purposes of this article, I'm going to proceed as though we're developing a design on paper.
We therefore need to transfer our garden onto paper. If you're designing a new garden, simply plan for the border as a component of the overall garden design. If this is an existing garden and you don't have a paper layout on hand, get yourself some good linear graph paper, a pencil and an eraser. Take your measuring tape, some markers, string and a friend, and get some of the key dimensions onto paper. The drawing must be to scale, so select some specific ratio of squares on the paper to actual units of measure in the garden. The outside or border dimensions of the garden are most important, as they will determine the quantity of materials you'll need to order.
When planning for the border, remember that the bricks themselves have specified dimensions. They have a known width, and the trench in which they will be installed will extend at least 4" into the garden and 4" into the lawn away from the bricks. In essence, your garden will be getting bigger with this project - take this additional distance away from the garden into account when laying out the plan.
One question that inevitably comes up is whether to design the border to follow the grade or to be at plumb level. Whereas retaining walls and multi-tiered planters should almost always follow true level, the opposite is usually true for single-course garden edging - it should follow the natural grade of the garden/lawn boundary. You therefore need to pay special attention to slopes; follow them if they run parallel to the brick course, but be careful if they run across the course; this may call for a retaining wall rather than a simple edging.
You'll need to select your bricks. There are all kinds of landscaping bricks and stones available. Many of them will work in this application, but not all. The ideal bricks for this kind of an edging have a relatively uniform height, have edges that interlock well and accommodate the transitions around a curve, and have a top surface which will stand up as the key feature. The bricks also need to be at least 4" high if they're going to be effective in keeping the grass out of the garden. They need to have the structural integrity to stand up to being walked on, and must tolerate ground moisture and frost movement.
I find that pre-manufactured precast retaining wall or "stacking stone" type bricks work best in this application, but I can see this working quite well with thick slate or flagstone slabs and other naturally carved stone. If you're using retaining wall bricks, you'll want to use the capping stones rather than the stacking type, because it's only the top surface of the stones that will show once they're installed.
Keep in mind that most precast bricks have a fixed minimum bend radius. That is to say, if the bricks are going to maintain a contiguous edge along the outside of the border, the radius of the curve can't be less than a value prescribed by the manufacturer. If your garden doesn't have very sharp curves or turns, you probably have nothing to worry about, but if it does have some decent bends, you'll want to check this dimension in the manufacturer's specifications. Also keep in mind that for linear borders, you might need to purchase special corner stones to make the 90° turns cleanly.
From a landscaping perspective, you must consider the key attributes of color, texture and form of the bricks in the context of your greater landscape composition. Here, color is clearly the most important choice; manufactured precast bricks come in a wide range of designer colors and color blends. Note the style of your landscape and the selection of materials and colors therein. Look for harmony with other similar hard materials in your landscape; decorative gravel, walkway and driveway surfaces, house finishes and statuary. Because a garden edging is most noticeable from some distance, look at your landscape from a distance and see which colors and textures are dominant, which are repeated, and which are clearly accents.
Supplies And Logistics
Once you have your design, the next step is to compile a list of materials and estimate the quantities. At a minimum, you'll need to purchase the bricks and the crushed rock for the base course, along with at least a little good garden soil for finishing purposes. If you're creating a new garden, then you'll need lots of good garden soil, and don't forget the plants!
The key to determining the quantity of materials lies in the dimensions of the border. You'll need a relatively accurate estimation of the circumference or perimeter of the garden edging. If you've done a design on paper, take yourself a piece of string and lay it along the middle of the border trench, i.e. along the centerline of the bricks. Wrap it all the way along and around the border so that you've accounted for every part of the border that will have bricks. Make a mark on the string where the border ends or where it meets the starting end of the string (for a closed garden).
Take the string and measure it to your mark, then multiply the measurement by your scale to calculate the actual length of the border in feet. To determine the number of bricks you'll need to order, divide this number by the length of the bricks. Since many precast bricks have a length which is tapered along the width to facilitate following curves, you'll need to make an approximation of the average length for this calculation. For a very linear border, use the maximum length, for a very curvy border, use the minimum length, and use the average for a border with both straight sections and flowing curves.
Now to determine the amount of crushed rock required for the base and filling in the sides, we'll again use the measurement for the total length of the border, but converted to feet. Take the measurement for the width of the bricks, add a total of 8" for the gap on either side, and then convert to feet. Multiply these two together, then multiply that number by 1/3' (4") for the depth of the base, plus one more "spare" inch (explanation coming later). This will give you the amount of crushed rock in cubic feet for the base.
Then take the total length measurement and multiply it by 2/3' (8") for the gap on either side of the bricks. Multiply this by the height of the bricks in feet to get the quantity of crushed rock you'll need for filling in the sides of the bricks. Add the two quantities together, and then divide by 27 to get the number of yards of crushed rock you'll need to order, as gravel is most often sold in cubic yards. You might want to add 5 or 10% as a contingency just in case your measurements are slightly off, especially if you're having the gravel delivered.
A note here on the crushed rock - not just any old gravel will do. I strongly recommend using a type of gravel known as "3/4-down crushed rock", often limestone. The "down" part means that it is comprised of gravel that is 3/4" or less, including a fine sand or silt which will help settle the base and make it stronger.
As for tools, you should plan to have a spade, a lawn edger, a heavy duty shovel which can handle the crushed rock, a rake, and a good wheelbarrow. Smaller items include string and wooden stakes for marking off the cut, a small 2x6 for tamping the gravel, and other sundry items you'll probably find in your garage or tool shed.
There are a few other things you need to consider. One is delivery of the materials. Unless you're undertaking a really small garden edging project, you'll need quite a lot of crushed rock, and the edging bricks are shockingly heavy, so you might want to plan ahead to have them ordered and scheduled to arrive well in advance of your targeted installation date. Be sure you have a "staging zone" in your yard where the delivery folks can drop off the heavy bricks, but which gives easy access to the worksite. And plan for the gravel to be dumped somewhere that can take it, i.e. other than on the lawn - it will completely kill the grass in a couple of days or less.
In Part II of this Info Sheet, we'll get into the actual installation process, so get your work clothes ready!