Looking for the best way to create and maintain a raised garden bed?
According to experts at the University of Minnesota,
"Raised bed gardening is a simple technique that can improve the health and productivity of your garden. Raised beds have better soil structure and drainage, allowing the soil to warm up earlier in the season, and giving you a head start on spring."
This guide will show you how to practically build a raised bed garden and recommend how to fill it with the right soil and plants. We will also give you tips on how to feed your plants, automate your watering, manage pests, and more.
But first, let's quickly cover the advantages of raised beds.
Why use raised garden beds?
Raised beds are a gardening solution that elevates function and reduces waste according to researchers at the University of Georgia. They can also add dimension to your landscape and make growing healthy plants easier.
There are five main reasons why you should consider using raised garden beds:
- Improved drainage. A raised garden bed has multiple benefits, but one of the most significant is that it helps with drainage. Unlike ground soil, the earth in a raised bed isn't compacted and will usually have perlite in it. This allows water to drain quickly and efficiently, which any gardener knows is critical for a healthy root zone.
But that's not the only benefit we should be paying attention to.
- Better air circulation. Raised garden beds provide better air circulation, which is important because plants need oxygen for their roots. When the soil is compacted, it can limit the amount of oxygen that gets to the roots, which can lead to problems with plant growth.
So it can help with aeration, but did you know raised garden beds minimize unwanted weeds from growing?
- Fewer weeds. Weeds can be a big problem in gardens, but they are less of a problem in raised garden beds. This is because it is easier to control the weed population in a small area than in a large area. Additionally, weeds are less likely to take root in loose, well-aerated soil.
We've all felt it before: as we age, it becomes harder to engage in daily manual gardening tasks. Luckily, raised beds can help with that.
Easier on your body. Gardening on the ground can be back-breaking work, and stooping and kneeling can also be rough on your knees and hips. Getting the plants off the ground helps ease some of that pain and makes it easier to access and see the plants.
But the biggest reason?
- Greater yields. Because raised garden beds provide better drainage and air circulation, plants tend to grow better. You will likely see greater plant yields if you grow them in raised beds.
So now that we know the advantages, let's dig a little deeper.
What size raised bed do I need?
There are many factors to consider when deciding the size of a raised bed.
The first is the type of plant you want to grow. Some plants, like tomatoes, need more room to spread out their roots, while others, like lettuce, don’t need as much space.
The second factor is the amount of sun your plants will need. If you’re growing vegetables that need a lot of sunlight, you’ll want a larger raised bed so they can get all the sun they need.
The third and final factor is how much time you have to maintain your raised bed. A larger bed will require more watering and weeding than a smaller one. The best way to decide on the size of your raised bed is to start small and see how it goes. You can always add more beds later if you need more space.
But what if you don't know how big your plants will get? Here are some common guidelines.
General sizing guidelines for common plants:
Vegetables: As a general rule of thumb when planting raised garden beds, each vegetable plant needs about 1 square foot (929 cm2) of space. So, if you want to grow four tomato plants, you’ll need a 4 x 4-foot (1x1 m) raised bed. You can get away with planting leafy greens like lettuce or spinach closer together since they don’t spread out as much as other vegetables.
Try planting them in rows with about 6 inches (15 cm) between each plant in the row and 12 inches (30 cm) between rows. This will give each plant enough room to grow without overcrowding the bed. Check out the back of your seed packets for specific plant recommendations.
Let's not forget our herbs, flowers, and fruits:
Herbs: Most herbs don’t spread out very much and can be planted close together. Try planting them in rows with about 6 inches (15 cm) between each plant in the row and 12 inches (30 cm) between rows. This will give each herb enough room to grow without overcrowding the bed.
Flowers: Flowers come in all shapes and sizes, so giving a general rule for how much space they need is tough. If you’re growing tall flowers like sunflowers, you’ll want to give them more room, so they don’t overcrowd the bed.
Try planting them in rows with about 12 inches (30 cm) between each plant in the row and 18 inches (46 cm) between rows. This will give each flower enough room to grow without overcrowding the bed.
Fruits: Like vegetables, each fruit plant needs about 1 square foot (929 cm2) of space. You can get away with planting small fruits like strawberries closer together since they don’t spread out as much as other plants. Try planting them in rows with about 6 inches (15 cm) between each plant in the row and 12 inches (30 cm) between rows. This will give each plant enough room to grow without overcrowding the bed. Vining fruits like watermelon, or pumpkin, need room to spread out, but technically the vines can overflow the raised bed area and onto the ground, or some folks trellis them on cattle fencing, which has a cool vibe to it.
Now you have your sizing down, but pay close attention to where you place your raised garden beds. Here's why.
Where should I set up my raised beds?
There is no definitive answer to the question of where the best place to build a raised bed garden is. It depends on several factors, including the climate, the type of plants you want to grow, and the available space.
Here's the truth:
Raised beds are best suited for areas that receive full sun for at least six hours daily.This is because most fruits, vegetables, and herbs need plenty of sunlight to produce healthy crops. If you live in an area with hot summers, choosing a spot that offers protection from the afternoon sun and heat is also important.
But that doesn't mean that you can't succeed with a raised bed garden in a shady area - you just have to choose the right plants. Consider planting shade-loving cool-season crops like lettuce, spinach, broccoli, and kale instead of sun-worshiping tomatoes or peppers.
Here are some common fruits, vegetables, and herbs with their light requirements:
6 to 8 hours of full sun per day | Carrots, squash, zucchini, beans
8 to 10 hours of full sun per day | Cucumbers, eggplants, peppers, tomatoes, corn
6 to 8 hours of full sun per day | Basil, oregano, rosemary, sage, thyme,
4 to 6 hours of full sun per day | Cilantro, dill, parsley
6 to 8 hours of full sun per day | Strawberries
4 to 6 hours of full sun per day | Blueberries, raspberries
Okay, are you ready to build your raised garden bed?
How to build a 4’ x 8’ raised garden bed:
If you would like a raised garden bed made out of wood, here are the materials and steps needed:
- 4” x 4” x 8’ pressure-treated lumber (2 total)
- 2” x 8” x 8’ pressure-treated lumber (9 total)
- 1 box of 3” deck screws
- Landscape fabric
- Optional: food-grade plastic sheeting
Here are the exact steps:
- Using the 4" x 4" x 8' pressure-treated lumber, cut six pieces 2 feet long each. These will act as the four corners and two middle support posts.
- Using the 2" x 8" x 8' pressure-treated lumber, cut three in half, giving you six pieces that are 4 feet long each. These will end up being used on each short end of the frame, stacking three on top of each other, giving you a 24” tall bed. (The other six pieces of 2” x 8” x 8’ wood will be used for the long sides of the frame by stacking three on each side.)
It's time to assemble your frame!
- Take three 4-foot long side rails and attach each end to one of the 4” x 4” support posts you cut to size in step 1. Use your 3" deck screws for this. Make sure that the ends of the side rails are flush with the top and bottom edges of the support post before screwing them in place. Repeat this step with the remaining side rail and end post to complete one-half of your frame.
4. To assemble the other half of your frame, repeat Step 3! Once both halves are complete, it's time to attach your 2” x 8” x 8’ rails to each side using the deck screws. Stack three high on each side, so you’re at 24” all the way around. Screw in the last two 4” x 4” x 2’ support posts in the middle of the 2”
x 6” x 8’ side rails for support.
And now you’re done with the frame!
But before we put soil in, we need to line it with landscape fabric all along the inside walls and bottom. This will help prevent weeds from growing up through your soil and give you an extra layer of protection.
To do this, first lay out a piece of landscape fabric large enough to cover the entire inside surface area of the frame plus have several inches of excess on all sides.
Next, staple fabric securely along all four sides, ensuring no gaps or openings where weed seeds could potentially enter. Trim any excess fabric beyond the stapled edge, then proceed to the next step.
An alternative way to ensure delicate plant roots won't come into direct contact with chemicals from the pressure-treated wood is to line the inside of the bed with food-grade plastic sheeting. It can be stapled or taped in place, creating a physical barrier between soil and wood.
And that’s it; you’re ready to plant in your new raised garden beds!
Planting your raised garden bed:
Starting with high-quality raised bed soil is crucial. We recommend using SoHum Living Soil as the base of your soil mixture. This soil is made from OMRI-certified organic materials and contains all the essential nutrients that plants need to thrive from seed to harvest. It contains beneficial bacteria, microbes, and fungi that your soil needs to thrive. To cut costs for big projects, you can cut down your living soil with topsoil, perlite, organic soil amendments, etc.
If you use a lot of topsoil in your mixture, you'll want to add perlite and soil amendments. These amendments will help improve drainage and aeration in your soil and provide additional plant nutrients. To prepare your soil for planting, mix equal parts of topsoil, perlite, and Gaia Green amendments according to package directions. There are many amendment options, so if you need help figuring out where to start, go with the All Purpose 4-4-4, everything else is optional. Fill the bed until it's 4-6” from the top.
Planting raised garden beds begins with seedlings. Space them evenly apart so they have room to grow. Either sow seeds directly into the prepared soil or transplant young plants from pots or flats. Once planted, keep seedlings moist by watering regularly and protecting them from strong winds or direct sunlight if necessary. As they mature, thin out overcrowded areas by transplanting excess seedlings elsewhere or giving them away to friends or family members who enjoy gardening.
Make a self-watering raised garden bed:
Now that your bed is full of soil, it is time to install a watering system. It’s essential if you live in an area with hot summers or little rainfall. Blumat Watering Systems are an excellent solution for the automatic irrigation of raised garden beds. The Blumat system will then deliver water directly to the roots of your plants based on the moisture level at the carrot sensor included with the system.
They don't use electricity and only water the plants as needed, automatically shutting off when it rains. They provide consistent moisture without over watering or flooding the bed - and that's ideal for keeping your beneficial microbe population thriving.
Where can I buy a raised bed garden?
There are a few places where you can buy raised garden beds. One option is to go to your local hardware or home improvement store. They will typically have a selection of different sizes and styles.
Another option is ordering them online from a retailer specializing in gardening supplies. This can be a great option to compare prices and get the best deal possible. Finally, you could always build your own diy raised garden bed. This option will take more time and effort, but it will be much cheaper than buying one pre-made.
Raised garden beds are an excellent way to grow plants and vegetables in a smaller space. They offer numerous benefits, such as better soil drainage, improved air circulation, less compaction of the soil, fewer weeds, and more efficient use of water. Plus they look great!
There are lots of options when it comes to buying or building raised beds, so do your research to find the best solution for you. And with a little bit of preparation and planning, you can be on your way to harvesting delicious fruits and vegetables from your raised garden bed in no time. Have fun!