Raised Bed Gardening: 7 Beginner Tips
Ready to build a raised bed garden in your yard? Wondering how to prep your raised beds for success? In this article, certified master gardener Liz Jaros offers 7 beginner tips for choosing, building, filling, planting, and caring for a raised bed garden.
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If you’re thinking about installing raised beds in your yard this year, you’re not alone. Raised bed gardening is surging in popularity due to its urban farmhouse charm and sustainable, home-grown advantages. It’s a movement more than a trend, and we’re fairly sure it’s here to stay.
The benefits of raised bed gardening include a longer growing season, greater soil control, less strain on the body, water conservation, and pest reduction, to name a few. The beds can be made from scratch yourself or purchased ready to assemble. They come in a wide range of shapes, sizes, and materials. They vary in design complexity to suit your needs.
Both seasoned and newbie gardeners are dedicating large sections of the yard to raised bed gardening. Before dumping a single bag of potting soil into the abyss, read through these 7 beginner tips for planting a raised bed garden. You’ll learn how to choose the right bed for your space, locate it properly, fill it with quality materials, and care for it like a pro.
Get the size right
Before beginners order beds online or dash out for construction materials, they should take a sketch pad and a measuring tape out into the yard. Examine the space where you’re planning to install your bed(s) and determine what size and shape would work best for your unique location.
Think first about scale. There’s nothing goofier than a teeny tiny planter box on a great big lot. If your property is large, plan a garden that’s proportionate to the overall space. Depending on your layout, a group of four evenly spaced beds with generous pathways will have more visual appeal than a massive, singular box running the length of the yard.
To keep the proportions right, buy or build beds with a height between 12 and 30 inches. You can opt for taller beds if mobility is an issue, making it easy to bend and tend your crops. However, lower beds are often more cost-effective.
Beds should be at least 12 inches wide but no more than 48. A 36-inch width is ideal for most layouts and gardeners. The length is more flexible and space-dependent, but a max of somewhere between 6 and 8 feet is the standard.
Use cardboard, lawn bags, newspaper, or rope to block the layout of your future beds. Think about access and create alleys that are generous and evenly proportioned all around. Seeing the scale of your plan at the intended site allows you to tweak the dimensions until they are just right.
Build beds in full sun
Unless you’re planning to grow hosta, fern, or other woodland plants, choose a location with at least six hours of direct sunlight per day. Raised beds are ideal for growing herbs, veggies, and flowers that require full sun exposure to be healthy and happy.
Choose a location with morning rather than afternoon sun, if possible, since many plants will wilt in the late-day heat. In wide open spaces, consider a location where they’ll benefit from shade in the west. Or plant a shrub nearby to offer some relief from the day’s most intense rays.
If you’re struggling to get enough sun, have a tree trimmer out to prune mature trees. Also, keep in mind that plants demanding ‘full sun’ do not need six consecutive hours of direct light. They just need six total. If a potential location gets a few hours here and there, it may very well be enough.
Use quality materials
You can make a raised bed from a wide range of materials. Bricks, cinder blocks, shipping pallets, boulders, and railroad ties are sometimes used by handy gardeners to DIY a makeshift bed. But in the interest of preserving your investment, creating the best aesthetic, and growing the healthiest plants, we recommend beds made of wood or metal.
Cedar is the optimal wood choice for construction due to its durability and natural weather resistance. Oak, pine, and maple will be less expensive. However, they are softer woods that will not last as long or have the same rustic charm as a bed made from cedar. They will also be more vulnerable to rot and insect damage.
Opt for wood that’s at least two inches thick and has not been chemically treated. You don’t want anything toxic leaching into your soil. Cedar beds may be stained or sealed with an environmentally friendly product but should never be painted or pressure-treated.
A galvanized steel or corrugated metal bed will give the yard a more industrial, contemporary vibe. Metal beds are fast becoming the container of choice. With a 20-year life expectancy, flexible sizing, diverse color options, and relatively easy assembly, they are a great option. When shopping around, look for manufacturers who use food-safe steel and sustainable processes.
Layer the soil
The best foundation for raised garden beds is fine gravel or crushed stone. Start with a level, two-to-three-inch layer over the entire area where you plan to build your beds. This facilitates even drainage within and around the beds while discouraging puddles on the work paths.
Once your bed is assembled and in place, cover the bottom with a layer or two of cardboard. This step discourages weeds while inviting earthworms and beneficial microorganisms to the garden. After the cardboard layer, fill taller beds halfway with logs, branches, sticks, leaves, yard waste, or food scraps. This is called a ‘passive’ or ‘cold’ compost layer because materials are left to break down naturally over time without intervention.
Herbs, veggies, and annual/perennial flowers have relatively shallow root systems, with the deepest root hairs extending roughly 12 to 18 inches below the soil surface. With that in mind, you’ll want the top foot or so of the bed to contain the best quality growing medium. In taller beds, adjust the cold compost level to achieve the right depth. Lower-level beds may not need filler at all.
On top of the filler level, spread a generous layer of compost. Purchase ready-to-go compost in bulk or bags from your local garden center, or make your own with a home composter and a little know-how.
The compost layer should account for about one-quarter of the top layer if you’re planning to use a pre-mixed potting soil or a raised bed mix). Increase the compost-soil ratio to one-half if you’re planning to fill beds with basic topsoil, and consider adding some worm castings or leaf mold to the mix.
Think about water
When you’re in the planning phase, evaluate a potential location’s proximity to your water source and think about how you’ll irrigate your new plants. The optimal way to water is through a drip system or soaker hose network. When snaked through a bed or arranged in a grid pattern, these systems will direct water toward thirsty roots and away from plant leaves, which is always the goal.
If a soaker hose system is not feasible, consider your other options. Will your hose reach the beds easily, or do you need an extension? Do you have a nozzle with a soaker or directional setting? Can you use a rain barrel to capture runoff water from a nearby roof? If your property has inground sprinklers, do they need a tweak or redirection to effectively and efficiently water your raised beds?
Once you’ve nailed down your watering approach, think about what you plan to grow and how much water those plants will need. Do not install a drought-loving perennial like stonecrop next to a water-lover like asparagus or squash unless you want one of the two to be unhappy.
Water in the morning, if possible. Any moisture that lands on your plants’ leaves will evaporate before the day is done, which reduces your run-ins with fungal conditions and/or chewing critters like slugs and snails. Consider adding a light layer of organic mulch to suppress weeds, retain moisture, and create a tidy surface area.
Time your harvests
Before you drop 25 lettuce seeds into your raised bed, take a minute to consider the outcome. If you’re successful, in roughly 60 days, you’re going to have 25 full heads of lettuce ready for harvest at the same time. If you’re planning to share with neighbors or donate to the local food pantry, disregard this warning. You’re doing a great thing.
If your goal is personal consumption, however, you’ll want to stagger your crops or reduce the quantity. Plant two or three seeds every other week through mid-summer, and you’ll have fresh, ready-to-cut lettuce on hand long into the fall. Read your seed packets or nursery tags closely and know your crop’s days to harvest to plan the fullest, most productive succession of plants.
Similarly, if you’re filling a bed with perennials for a cutting garden or personal enjoyment, you’ll want to choose plants that will bloom sequentially from spring through fall. Think ahead and map your bloom times out on paper to create beds that are lively and colorful all season long.
Provide protection
Many of us choose to install raised beds because we are tired of feeding the rabbits and deer. Consider this when you’re determining how tall to make your beds. A two-foot height might shut down the bunny buffet, but the deer will find it even more attractive since plants are now at eye level. To exclude the neighborhood deer, run a chicken wire fence around your beds or work in some deterring plants.
Educate yourself on companion planting before making your selections. If you’re worried about aphids, work some aromatic herbs like garlic, chives, or cilantro into the mix. Marigolds and nasturtium are other known pest repellants. Similarly, there are some plants like tomatoes and cucumbers that do not grow well together. Understanding and utilizing these symbiotic plant relationships will help you up your gardening game considerably.
Monitor the garden often for changes in leaf color or flower quality, and watch the soil for signs of viruses and fungus. Familiarity with the status quo is your best weapon against pests and disease, and these things should be dealt with swiftly to prevent cross-contamination.
Keep an eye on the weather forecast, particularly in spring. If you’ve jumped the gun and planted too early or an unseasonable cold snap is expected in your region, covering young sprouts with a sheet or light tarp on cold nights might save their lives.
Final Thoughts
The soil in your raised beds will shrink and break down as it matures, especially if you’ve incorporated a layer of cold compost that will decompose gradually. Plan to replenish your beds with compost and additional potting soil each fall until their levels are stable and the soil makeup is optimal for continued success.
Enjoy your new, beautiful garden set-up!