What I love about raised bed gardening (besides less back ache) is that it’s such an easy way to add big impact to your garden design while simplifying the whole gardening process, from starting straight off with great soil to growing bumper crops. And there are so many ways you can use a raised bed. Yes, growing veggies is what often comes to mind first. But a raised bed can also be a fast fix when you’ve got no soil at all or limited space and it’s an easy way for first-time gardeners to substantially enhance their garden and enjoy real growing success. Want to get creative with a new raised bed in your garden? Here are some space-saving ideas and no-fail shortcuts.
MAKE YOUR RAISED BED A MULTI-TASKER
Raised beds are the answer, of course, when you’ve only got a hard surface such as paving or asphalt to work with or when the soil is very poor. But the rooftop garden shown at left, photographed on the roof of a housing co-op in downtown Toronto, does much more than give the residents a place to grow things. It’s a real multi-tasker in a small space, providing lots of room for growing perennials as well as offering a built-in bench for a a shady break and acting as a support for a rose-covered archway. Why not put your raised bed to work doing double duty:
- adding lighting effects to your garden. Trim the tops of the walls of your raised bed, adding an overhanging lip. Then tuck a string of outdoor lights running just under the lip. Now you can enjoy your softly glowing garden at night.
- making your garden more private. Build your raised bed with one side extra tall and you’ve got a self-supporting wall that can add privacy and be used to support vining plants.
- dividing your space into separate “rooms”. Assigning separate areas in a garden and giving each a different planting scheme is a classic garden design trick to make even the smallest garden feel larger. But making the separation between these areas can be a challenge. Raised beds can help you delineate these areas while providing extra garden areas themselves.
PREVENTING EROSION AND MAKING MORE SPACE
I used raised beds when I renovated the backyard of my former home in the heart of urban Toronto into my tiny garden hideaway. Using beds solved a variety of problems. The ground level of my neighbour’s garden (behind the tall fence seen in both photos) was higher than my garden by a couple of feet so the raised beds served as a kind of terracing to help deter erosion. Also, my original yard was filled with chunks of rotting concrete and very poor soil so the beds neatly avoided all of that. Varying the heights of the beds created interest, accommodated tree roots and made a very small garden appear much roomier. But I think the best part of these raised beds is that my dear old cat loved what she thought was a wooden pathway made just for her.
ELEVATING A BELOW GROUND AREA
The two photos seen below show how raised beds can turn a below ground entranceway into a cheery and welcoming space. I’ll sidestep the philosophical question as to whether the example on the right is actually a bed that’s raised or a ground-level bed with one side that’s been lowered.
So far, I hope I’ve convinced you that raised beds can be as much an important garden design element as a practical option for raising vegetables and growing ornamentals. Conveniently, whether you’re planning an elevated flower bed or itching to grow your own salad makings, the basic principles in successful raised bed gardening remain the same.
SHORTCUTS TO SUCCESSFUL RAISED BED GARDENING
1. Start clean. This is particularly important if you’re planning on growing vegetables. If you’re strictly organic, you’d do this even if you weren’t going to eat what you grow. By simply sticking to building materials and soil products that aren’t doused in chemicals, your raised bed will be a healthy addition to the environment in general. (Remember, a raised bed is meant to last a long time and its impact on critters and the surrounding soil will also last a long time.) So build your bed with non-toxic materials such as untreated wood–rot resistant cedar is great. Stone is another organic and very handsome albeit more expensive option.
2. Get to your height by knowing your depth. Think about the root systems of the plants you want to grow when you’re deciding on the height of your bed. If you’ve got your heart set on growing deep rooted plants like carrots, plan on a bed wall that’s at least taller than your average carrot is long.
3. What’s on the bottom? If you’re building your bed on top of an impermeable surface like concrete or asphalt, on unhealthy soil or you’re worried about tree roots invading it, line the bottom of the bed with landscape fabric (which isn’t strictly organic but works best in these situations). But if the soil is perfectly fine, don’t line the bottom of the bed.
4. Now start saving up old cardboard boxes. If you’re building your bed on healthy lawn, there’s no need to dig up the grass. In fact, the grass will be a bonus. Once your bed walls are up, water the lawn inside your bed thoroughly. Then add a shallow layer of compost mixed with well-rotted manure. (Packaged compost and manure from the local garden centre will do.) Top this with a layer of cardboard, being sure that you’re not using any board that’s covered with toxic inks, taping, sticky labels, staples, etc. Soak the cardboard layer with your hose. Then fill up your bed with healthy topsoil.
Why the cardboard? Worms love it. Or, more to the point, they love the glue in it. Yum! The cardboard is an earthworm magnet so you get plenty of earthworms helping your raised bed soil stay healthy and fertile so you don’t need to add a pile of fertilizers and other unhealthy soil amendments.
5. Skip the gravel. Notice I didn’t mention anything about adding a layer of gravel for “improved drainage”. It’s a myth that gravel improves drainage in any container, whether you’re looking at a flower pot or a raised bed. Moisture moves through soil due to the powers of gravity and adhesion (to soil particles). If moisture encounters materials courser than the soil itself, such as gravel, the movement of the moisture stops moving until the soil is nearly saturated. Not good. The research on water movement in soil by Walter H. Gardner of the University of Washington in the 1950s, proved that gravel won’t help or speed up the process of drainage. It hinders it. (Besides, you don’t want to make it difficult for your good buddies, the earthworms, to get up into your topsoil. See above.) What’s more important when prepping the bottom of your raised bed is that you have a level surface directly underneath the bed as well as in the immediate surrounding area to avoid water pooling.
6. Remember that a raised bed ain’t exactly like a regular garden bed. The very nature of a raised bed–soil elevated in an above-ground container–means that certain things will happen to it that won’t happen to the rest of your garden. In a good way. But as much as it would be nice to maintain your raised bed on the same schedule as the rest of your garden, you’ll need to keep in mind its extra special quirks:
- The soil in your raised bed will warm up faster in the spring than the rest of your garden. This is a good thing. You can usually plant seeds out in a raised bed sooner than in a normal garden bed. How do you know the soil is ready for planting? Just grab a handful and squeeze. If the soil is still very cold, your seeds won’t germinate. You want to tuck your little seeds into warm soil–soil that feels comfortable in your hand.
- The soil in your raised bed will get colder faster in winter. If you’re growing perennial ornamentals, for best results choose plants that can thrive in colder zones than your own.
- The soil will likely dry out faster than the rest of your garden. I say “likely” because the rate at which your bed dries out depends a lot on the materials you used to build your bed, where it’s located (sun or shade), the size of it, the soil used, etc. The shortcut to success in this regard is to just keep in mind that your raised bed is a different animal than the rest of your garden beds. Treat it as it’s own unique environment and you’re good.
Here’s a photo of the awesome raised bed my stepson is building. He and his girlfriend are about to try growing vegetables for the first time.
Photo courtesy of Lee Reynolds.
I wish I was there right now. This photo was sent to me via text message–such are the conveniences of technology and the realities of an extended, geographically-challenged modern family. They’re trying out gardening for the first time this year, using their raised bed to grow vegetables, and I can’t wait to see lots more photos and hear in their voices the sounds of discovery, wonder and happiness that gardening can bring.
Ministry of the fence 