There has been a lot of hype lately about growing plants and vegetables in raised garden beds, but raised gardens come with some notable disadvantages. In some cases, they only make your garden harder to maintain!
I understand the benefits of raised gardens, and for some of you, it’s just the right thing.
For example, raised garden beds can save your back (no more bending over is nice, after all). If you live in an urban area with no garden space, you can put a raised garden anywhere, even on concrete. And if you’re renting, you might not even be allowed to dig up the garden.
But… by growing plants in a contained space like a garden bed, you may be making your job as the gardener much more difficult. Let’s get into the details and discuss the disadvantages of using a raised garden bed. After that, we’ll share tips to help you overcome the cons of raised garden beds and have a successful raised garden.
- The Disadvantages of Raised Gardens
- 1. Raised Garden Beds Are Expensive
- 2. You Need Exceptional Soil
- 3. Raised Garden Beds May Offer Too Much Drainage
- 4. Raised Garden Beds Increase Water Evaporation
- 5. Wood Robs Nitrogen From the Soil
- 6. Raised Garden Beds Are Prone to Rot and Rust
- 7. Wooden Raised Garden Beds Attract Termites
- 8. Overplanted Garden Beds Lack Air Circulation
- 9. Raised Beds May Be Too Small for Some Plants
- The Advantages of Raised Garden Beds
- Tips for Successful Raised Gardens
- Final Thoughts
The Disadvantages of Raised Gardens
Everything comes with some distinct disadvantages, and raised garden beds are no exception to this rule.
Raised garden beds might be the right option for some people, but they are not the best option for everyone. Growing your plants in the earth is much easier and better than using a bed. Why is that, you ask?
Well, let’s look at the most significant disadvantages of using a raised bed vs. growing your plants in the ground:
1. Raised Garden Beds Are Expensive
Raised gardens can get expensive. Not only can the upfront cost of material for the bed be high, but the soil and compost you’ll need to fill it can be pricey, too.
You can’t use any old soil dug up from somewhere when filling a raised garden bed. Instead, the soil must be of exceptional quality. There’s no room for error (I’ll explain more about this below).
Don’t discount the labor cost either. Most of us will build raised garden beds from scratch or buy a kit. But, it can take a lot of time of effort, not to mention the back-breaking work of filling the thing! Many a wheelbarrow goes into a raised garden.
Then, there’s the additional cost of new materials for bed repairs, fertilizers, and other soil amendments. Compared to in ground gardening, beds are not cheap.
2. You Need Exceptional Soil
The soil in a raised garden needs to be exceptional. The soil is everything. Mother Earth can’t give you a helping hand with a raised bed, as you have walled her out.
When you use in ground gardening, you have a whole ecosystem you can feed and nourish. You can encourage worm and microbe activity. Your garden is an ecosystem on its own, and nutrients share around.
However, raised bed garden soil tired much easier than the native soil in your garden. You’d never think of replacing the soil in your in-ground garden (not usually, anyway). However, you may need to replace the poor soil in your raised garden.
We replace the soil in our raised gardens yearly. After a year, it lacks nutrients and doesn’t grow nice vegetables anymore. If you are on top of adding nutrients, your raised garden soil might last longer. I have no doubt you’ll need to replace it at some stage, though.
3. Raised Garden Beds May Offer Too Much Drainage
One of the most significant disadvantages of raised garden beds is that they get really dry really quickly and often require very frequent watering.
I have seen a lot of tips to “not overwater” raised gardens. There’s no such thing. When the soil in your raised garden is good, water drainage will be no problem. It’s tough to overwater, and sometimes, it’s tricky to even keep moisture in the soil.
Every time you water your raised garden bed, you create a “tunnel” for the water to run down. Water always finds the easiest way down, so it keeps going down these tunnels. When this happens, the moisture doesn’t get anywhere else in the bed.
Knowing when to water is also harder. It’s not rocket science in the garden. Stick your finger in and you can feel whether it’s moist or not. However, in a raised garden, just because it’s moist doesn’t mean it’s wet enough around your plant’s roots.
On the other hand, if you live in an overly wet climate, this excessive drainage could help you keep heavy rains from flooding your garden.
4. Raised Garden Beds Increase Water Evaporation
Raised garden beds are also much warmer than ground soil since the sides of the bed are exposed to sunlight. While that can be a benefit for starting plants in early spring and extending your harvests in cold weather, it also increases water evaporation, leaving the soil dryer.
Still, how quickly your beds lose moisture depends a little on the area you’re in. For example, in a cold area, this will be less the case than in the hot tropics.
For example, I have a raised garden next to my carport and it needs watering every other day when it’s not the wet season. It has a deep layer of mulch, and the raised garden itself is deep, but it still needs watering all the time.
Additionally, unlike plants in container gardening, you can’t plonk a raised garden in a bucket of water to rehydrate it. When your raised garden gets dehydrated, it’s tricky to rehydrate the soil. You may even have to resort to wetting agents and the like.
A thick layer of mulch will help prevent too much evaporation and tunneling, but it’s unavoidable to some extent.
5. Wood Robs Nitrogen From the Soil
If you have a wooden raised garden bed, the wood will decompose around your beds over time. As it decomposes, it robs all the nitrogen from your soil and acidifies it, ruining the soil quality. That’s why it’s never a great idea to fill raised garden beds with logs, wood chips, and twigs.
You can fix this nitrogen deficiency by adding soil amendments and raising the pH of your soil, but this will take some extra work. You’ll also need pH tests and soil nutrient tests to check the levels before adding anything.
6. Raised Garden Beds Are Prone to Rot and Rust
Another big disadvantage of raised garden beds is that they don’t last very long. While the short life of a garden bed means that you’ll have to invest in repairs or replacement eventually, it also means that the material could cause an imbalance in your soil or introduce pests.
Having wet, or at least moist, soil sitting in your raised garden bed 24/7 does a lot of damage to most materials. Anything metal will rust, potentially causing an iron overdose or other issues in your soil. Wood rots.
Rusting metal raised gardens are also sharp, often causing nasty cuts.
Additionally, you must consider the safety of the materials you plan to use. Cheap wood, railroad ties, or treated wood might contain some preservatives like arsenic, and you really don’t want that leaching into your garden soil. Paints and artificial wood can also contain lead and plastics that might be toxic.
7. Wooden Raised Garden Beds Attract Termites
Moist, deteriorating wood attracts termites, which means that your garden beds are prime targets for these little bugs. Termites are a real nightmare if you’ve got wooden structures on your land, especially your house! We had a huge termite infestation in our last house, which was an old train carriage.
They destroyed at least 60% of the house before we stopped them. They ate all the window frames, the door frames, and anything that wasn’t proper hardwood.
8. Overplanted Garden Beds Lack Air Circulation
Air circulation is critical if you want to keep mildew and many pests from infesting your garden. Raised garden beds, with their limited space, often fall victim to diseases and pests when you aren’t careful about planting space and pruning.
For example, if you look at the picture above, you’ll see my bee balm plant, which I grew in my raised garden bed alongside a passion vine. These plants developed white powdery mildew last year. Unfortunately, this mildew spread to all of my pumpkins and squash, my tomatoes, and my herbs.
I fumbled there because I overplanted, neglected to prune things back, and didn’t give things enough air circulation in the bed.
So, don’t make the same mistake as me. Give your plants ample space and keep pruning to increase air flow.
9. Raised Beds May Be Too Small for Some Plants
Every plant is different, and deep beneath the soil, each plant’s root system is unique, too.
Some plants may only need a few inches of root space to mature. However, many common garden plants, such as tomatoes, corn, and squash, need more than a foot of soil space to bear fruit.
So, keep in mind the plant root size of what you want to grow when considering using a raised garden bed.
The Advantages of Raised Garden Beds
We’ve already discussed this topic in-depth in our other article, How Deep Should a Raised Garden Be? so I recommend reading it if you want the big picture. However, I’ll briefly touch on the highlights here.
Raised garden beds, as I’ve already mentioned, offer better access for gardeners with mobility issues and those living in an urban area with very little soil space to work with.
Additionally, they can be nice if your native soil is not great for growing the type of plants you want. For example, in dry climates with sandy soil, a bed gives you the opportunity to control the soil more directly and keep it moist for a veggie garden. The same is true for heavy clay soils.
Plus, a bed offers you more protection from weeds.
Beds are also naturally warmer since they have sun exposure on all sides, allowing your garden to survive cold weather and frost a bit better. They are also less prone to soil compaction since you won’t have any foot traffic on the surface.
Tips for Successful Raised Gardens
Despite the disadvantages of raised garden beds, there are clearly still some advantages.
So, if you have decided you want to try raised bed gardening, here are some tips to make it work:
- Consider in ground beds. In ground raised garden beds are a type of bed that basically consists of short walls of material that sit on top of your native soil and have no bottom. These beds are fantastic for increasing soil moisture and helping your garden stay more fertile.
- Start small. Start with small garden boxes to see if they work for you. You can grow some easy seedlings like lettuce, parsley, and basil in a smaller bed.
- Don’t forget the mulch! Mulch can suppress weeds while also preventing water from tunneling straight out of your garden bed’s soil.
- Make sure you use healthy soil. Good soil is important in any garden, but it is essential in a raised garden. There’s not a lot of room for error here, so get the best soil you can afford and avoid filling your bed with native soil.
- Make the garden bed as deep as you can. Shallow raised garden beds are much harder to deal with than deep ones. If you want to learn more about how deep to make your garden beds, we’ve dedicated a whole article to it and made a handy chart to help you make the best bed for the plants you want to grow. Check it out here.
- Add trellises to grow vegetables up and save space. One zucchini left to its own will take up a huge amount of space, for example. Train it up so you can grow low-growing vegetables in front. Here are some sturdy trellis ideas to help you add more vertical space to your garden beds.
- Fertilize regularly. Use a good organic fertilizer and reapply it just as often as the packaging says.
- Start a compost pile so you have a ready supply of goodness to add to your raised garden. Remember, raised gardens do not “make” their own nutrients like an in-ground garden might. You’ll have to feed it everything it needs.
- Plan for a cover. Raised garden beds are even more susceptible to bugs and animals than in-ground gardens. It’s a good idea to plan for an animal-proof cover if the need arises. It could be anything from a simple net cover to a complete roof.
Because of the many disadvantages of raised garden beds, I don’t think you should start a raised garden if you don’t have to. The disadvantages far outweigh the benefits.
The few raised gardens I have don’t perform anywhere near as well as a nicely-prepared in-ground garden.
Try to grow in-ground if you can. You’ll find that growing vegetables is easier in the ground than in a raised garden. Don’t be afraid to put your edibles nice and close together in the ground (see why in my Wild Food Forest article), and try growing some “weird” veggies too!
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