Raised beds are a great way to confine your plants to the healthiest soil possible and in a space that makes it easier for you to plant, maintain, and harvest. There are many benefits to using raised beds on your property.
In this guide to raised beds, you will learn why you need raised beds, how and where to build and place them, and how to maintain them too.
What is the Point of Having Raised Beds?
Raised beds allow you to control the health of the soil in which you are growing your plants in. A raised garden bed is a garden bed made up of organic, nutrient-rich soil that sits on your existing soil and is constructed on four sides with food-safe materials.
This type of garden bed encourages plant roots to grow down and outward. It provides healthier soil with less chemical leeching into the soil and can make it easier to reach into the bed when gardening or harvesting.
The Benefits of Using Raised Beds
Although raised beds can be pricey depending on the materials you use, and it takes some time to build them, the benefits of raised beds far outweigh any cons.
Some of the benefits of having raised beds include:
- They allow you to garden just about anywhere you want. These beds can be built on almost any surface and in pretty much any climate.
- Raised beds allow you to "create" the perfect soil mixture for your plants. And as an added bonus it is contained so there is not the "washing away" as normal in-ground garden soil may do. You can mix the exact mixture needed for the specific plants you will be planting right from the start.
- You can plant a bit earlier. There are many bed covers you can create or buy for your raised beds. This means you can plant in them sooner than you could in the ground. You may be able to eliminate the need to start indoors in some climates. This saves space indoors or in the greenhouse.
- Minimal weeds will appear in raised beds. Even if a few do appear, they will be easily removed by hand due to the looser soil than what they normally grow in with in-ground planting.
- They are a great solution for the elderly or handicapped. They can be built to any height allowing gardening to be enjoyed instead of dreaded.
- Pest control is minimized. You can monitor your beds easier in a raised bed. There are also screening and covers available to cover the beds to prevent pests. Now you can protect the one crop that may be affected without having to cover all of the gardens.
- You can grow much more food in far less space. In a raised bed you can utilize almost every square inch of gardening space easier than in a ground garden. Therefore, you will be blessed with a more bountiful harvest.
Material Options That You Should Never Use
The best and least expensive option for materials is, of course, using what you already have on hand. However, that is not always the safest way to build these types of beds. Let me explain why.
You have to be aware of the "ingredients" of your materials. Some wood has been treated with chemicals you may not be aware of, especially treated wood and railroad ties.
Treated Wood for Raised Beds
Many of the treated wood boards we purchase at Home Depot and Lowes, for example, have levels of chemicals in them. Thus the term "treated wood". However, these chemicals can leach into the soil, into the plants, and unfortunately, into our bodies when we consume that food.
I don't think anyone would want to put chemicals like arsenic and copper for example, into our family's bodies. What you need to know is that using treated wood may be exactly what you are doing.
Simply sitting on the side of raised beds and placing your hand on the treated wood can cause both of those chemicals to enter your body as they are leaching from the wood of the beds.
Now, on the flip side of that if your soil in the raised beds is high in organic matter, (you are using good compost, I assume) you should be ok since plants in healthy soil will not absorb arsenic. That is unless it is almost depleted of phosphorus.
You need to make your own decisions here, I don't take the risk.
Concrete Blocks
Concrete blocks and cinder blocks are often used interchangeably. However, cinder blocks refer to blocks made over 50 years ago, and probably not what you have. Concrete blocks, however, are what we find now.
Concrete blocks are made from Portland cement. One of the main ingredients found in Portland cement is fly ash (ranging from 15% to 25%). It’s used to make concrete blocks lighter yet stronger.
Fly ash is a fine powder byproduct of coal burning, so In other words, it’s a petroleum byproduct. This means it contains various amounts of toxic metals; including arsenic, lead, and mercury.
The risk of these leaching into the soil is high when the concrete is broken into smacker pieces. And again, the better the organic matter of the soil, the lesser the risk. However, there isn't much research available about fly ash ingredients in garden soil. Again, you decide.
Galvanized or Metal Troughs
I really couldn't find a ton of information on the health risks of planting inside these two materials. I did find out that they are usually both dipped in a zinc mixture. Zinc is actually used in small amounts in plants.
However, too much zinc would mean dying plants. Again, I act on the side of caution. Although for many, many years, people transported water in galvanized buckets, and the animals we slaughter tend to eat from galvanized feeders, I would rather not use them. And again you must make your own choices.
Tires
So many people have become garden creatives with their tire planters in the last few years. I, however, refuse to do so.
Our landfill here, in Central Florida, and many others will not take tires. Do you know why?
According to eco-green equipment, " Their hollow, rounded shape takes up the valuable shape in landfills. Additionally, tires often don’t stay buried. They have the unfortunate habit of trapping gases like methane and then “bubbling up” through landfills, ripping through landfill liners in the process." You can read the entire article on the Eco Green Equipment website.
I do not want methane or any of the other petroleum-based yucky stuff in those tires in my food source!
The Best Materials For Building Your Beds
The best material for raised beds is raw wood. The best raw woods are the ones that are unfortunately the most expensive though. Some cities and towns may have a hard time finding the right raw wood types also.
These include:
- Cedar
- Black Walnut
- Redwood
- Osage Orange
- Oak
- Cypress
- Black Oak
The above types of raw wood tend to be more rot-resistant, pest resistant, and last longer because they are more durable.
We use oak. Of course, oaks are dominant on our property. So when we cut down oak trees, we save the longest straightest limbs and logs for things like fencing and raised beds. These last a few years.
You can use untreated pine. It will not hold up as long as the others above, but it is much more affordable if cost is an issue. It is also readily available pretty much anywhere.
Size of the Beds
As far as what size to build your beds, just remember this, no more than four-foot wide. At four feet wide you can easily reach across to the opposite side without stretching too much. If you make them any wider, it may be difficult to reach the other side and you will have to constantly walk around the bed.
The length, however, can be any size you want it to be. I have 4ft. wide x 20 ft long beds for vegetables and 3ft wide x 5ft long beds for herbs. I even have 4ft x 4ft beds for small fruit trees. Length is whatever you need it to be.
The height should be between 12" - 18" for an average height. However, you can design a six-inches-high bed for lettuce and some herbs that will work well. 18" is a perfect size to sit comfortably too.
If you want higher beds, go ahead. Please keep in mind, the cost to fill them increases with every inch taller you go. If cost is an issue you may want to stay with the 12" - 18" height.
Placing Your Raised Beds
Placing your raised beds is fairly easy. As long as the ground is mostly level, just about any place should work. You can build a floor in your raised bed if placed on a patio or hard surface, however, this post is specifically for placing your bed on dirt.
Before placing your bed you may want to prepare the surface it will be on. This may include digging the first layer of grass and especially weeds out of the soil. Digging a bit deeper than the roots of the grass should suffice.
You may also wish to break up the soil at that point. This is for the more shallow beds so that the deeper roots can penetrate the soil eventually.
You may want to build your beds in place if moving them after being built is going to be a problem. We build ours in the place they are going to stay regardless of what size.
Other Considerations for Your Raised Beds
Other considerations to keep in mind may include the following:
- The proximity to a water source. You want to be able to water the bed in the event that there is not enough rain. Remember, the longer the hose you need, the more work to return the hose to its original space. You may have to cross other beds too. Keep the distance close as possible. Consider using rain barrels.
- Consider predators. If rabbits are in abundance on your property, a six-inch bed with lettuce next to a tree line or an open field probably is not the best placement. Consider what predators and wildlife may be an issue and adjust your placement if necessary.
- Is fencing needed? Sometimes kids throwing a ball and mishaps with your hubby using the weed eater, (I would know), happen. Decide whether or not the raised beds need fencing or protection from these things before you plant.
- Will it get enough or too much sunlight and/or water? Don't place your beds where they get sun from morning til dusk. Most plants require 6 or 7 hours but many do not. Also, pay attention to any heavily puddling spots or run-off paths when it rains. You don't want your beds in a direct path.
Using the Right Soil
When filling your raised beds I recommend the following:
- 60% topsoil
- 30% compost
- 10% peat moss and pearlite mixture
If you are growing vegetables, you may not want to add more than 10% of the peat moss. It is actually considered acidic and really isn't great for growing vegetables. Add more compost or vermiculite instead.
You may want to have your topsoil delivered if you need a lot. It will be less expensive to have it delivered in bulk than to buy those individual nags in the long run.
You can use your own compost. If you need more information on starting a compost pile, read The Ultimate Guide To Composting At Home.
I use a wheelbarrow to mix up my parts and then wheel the mixture to the bed and dump it. This way it is already mixed by the time the bed is full.
It's Planting Time!
Now the fun begins. Whether you are planting seeds or starter plants, be sure to allow enough depth for the roots to grow. Lettuce grows well in a 6" deep bed, but I wouldn't plants beets in a bed that shallow.
Now of course the exception to this is if the soil under your bed is nutrient-rich enough for those roots when they reach that area.
When planting watermelon or squash that throws vines, you may only want to plant one or two seeds or plants so that you can harvest more easily later on. And don't be afraid to grow vertically.
A raised bed of peas and beans may require string or some type of trellis but will allow more plants to be in the same bed.
Be creative and design your beds for smart use of space and ease of planting. be sure to include small fruit trees, berries, and even sprouts.
I would love for you to share your images or thoughts and ideas with me. Just enter them in the comment box below! Happy planting.