The Advantages & Disadvantages Of Raised Beds Are Frequently Discussed By Gardeners & Allotment Plot Holders. But There Is A Lot Of Confusion. Here’s My Professional View.
Table of Contents
What Are Raised Beds?
This is where much of the “Advantages & Disadvantages Of Raised Beds” confusion starts. Many new gardeners seem to confuse raised beds with enclosed beds. A raised bed is defined (in all the dictionaries I’ve consulted) as an area of land that is raised above the rest of the area. It is often contained within an “enclosure’ of some sort. This might be a wooden, metal, concrete or even stone enclosure of some sort. BUT the enclosure isn’t the vital part, the raised area is the essential element of the definition. And as can bee seen from the previous link to Wikipedia they are in agreement, the area must be raised.
So a pallet collar or other form of enclosure doesn’t make the bed a raised bed, UNLESS the soil is raised. And many gardeners, myself included, wouldn’t consider any bed a raised bed if it was only raised an inch or two. An inch of compost inside an enclosure doesn’t really seem to satisfy the term “raised” to any extent.
How High Is High Enough To Be Raised?
Someone is bound to ask this question. So let me say there is no agreed definition. Common sense needs to be used.
Let’s start by asking ourselves why we would raise the soil level at all. As a market gardeners I never raised my soil levels. Farmers don’t raise their soil levels (and I have considered how potatoes are ridged, but the ridges are formed by moving soil and forming a lower area to produce a ridge!).
The idea behind raised beds is usually to amend the soil or make it easier to reach the soil level. There is also an argument for the use of beds to make the site look more aesthetically pleasing. But I’ll delve into all these in the next section.
Before leaving this section, let me address why people often feel the need to enclose a bed with a pallet collar or similar. I believe it is to make the plot more manageable. It’s a psychological thing for many people I talk to. They see a huge expanse of soil in front of them and it is so big it freaks them out. They can only imagine being able to manage a smaller piece. So they set about building small beds within the plot simply because it looks more manageable to them. I understand this. A large plot can be overwhelming. But creating beds like this can actually make things worse in terms of the workload, simply because you have to start by building the beds.
A simpler way is to simply divide the plot up with a path and a few canes or sticks into manageable sections.
Why Use Raised Beds?
Some people want to raise the soil level so they don’t have to bend too much. I sympathise with this. Decades of bending to plant and harvest tens of millions of lettuce has left me with a back that prefers not to haver to bend more than need be!
However, it is interesting to note that several gardeners I know that use wheelchairs tell me that beds are actually a nuisance and means they cant reach their crops. They struggle to reach far enough into a raised bed and prefer to garden at ground level. They use tools on longer handles and find it much easier.
Raised beds also mean that a wet site is useable during very wet times. The logic is that if the site has a foot of flood on it the crops can be several feet above the flood level. That makes sense to me, though there are disadvantages that I’ll cover later.
Raised beds also mean were can garden where the bedrock is at surface levels and we have no soil. Ditto, it makes sense where there is concrete that is impossible to remove.
Mandatory Raised Bed Systems
Some systems such as Square Foot Gardening mandate raised beds as part of their gardening technique. Personally I don’t favour any system that is this rigid about raised beds.
Advantages & Disadvantages Of Raised Beds
In the next two sections I’ve taken some of the arguments I frequently see both for and against the use of raised beds. It is an area of gardening that tends to generate strong feelings and emotions and I’m going to try to inject a bit of common sense into the discussion. Though it’s undoubtedly just as likely that my “common sense” will be seen by some as being dogmatic and provocative. But, bearing that in mind I’ll do my best!
Advantages of Raised Beds:
Enhanced soil quality
Raised beds allow for the creation of optimal soil conditions, incorporating ample organic matter and amendments for fertile, well-draining soil.
I would argue that in most cases this also applies to soil at ground level. The exceptions would be where the soil regularly floods due to conditions beyond the landowners control, where there is rock rather than topsoil and where there is concrete rather than soil.
Improved drainage and aeration
Raised beds provide better drainage, preventing water-logging and root rot. Aeration is also enhanced, encouraging healthy root growth and minimising compaction.
Again I would argue all these plusses are possible with soil at ground level. Well structured soil is a mix of organic matter, mineral constituents, and voids/spaces that contain varying amounts of air and water.
Warmer soil temperatures
Raised beds warm up faster in the spring, enabling earlier planting and a longer growing season.
They are then capable of getting too warm and well drained in summer. Plus they can cool down much lower in winter.
Reduced weed pressure:
The raised sides of the beds create a physical barrier, making it more challenging for weeds to establish themselves.
Unless the sides are buried deep into the bed the roots can grow under the beds. That’s what roots do, they live in the soil! Plus weed seeds, blowing in the air, can blow onto a bed just as easy as onto soil at ground level. For example, a pallet collar sat on the soil isn’t going to stop many roots growing from the path into the “raised bed”.
Easier access and reduced strain
Raised beds are more accessible for gardeners of all ages, reducing strain on the back and knees.
This one resonates with me as my back is the thing that aches most when I garden. However, note my previous comments about some wheelchair users preferring NOT to use raised beds
Improved soil control and customisation
Raised beds allow for fine-tuned soil preparation and customisation, tailoring the growing environment to specific plant needs.
If you are on chalk soil and want to grow rhododendrons in your garden I can see how a raised bed or container containing acid soil makes perfect sense. And the contrary is true where a basic soil is required and you are on acid soil. Ditto if you want a sandy soil, a clay soil or whatever that is not what you have in the garden, then it makes sense. But otherwise the soil can be amended with or without a raised bed.
Disadvantages of Raised Beds:
Building raised beds requires upfront materials and labour, plus they need filling with top soil, compost or other materials, adding to the overall cost of gardening. If you want to calculate how much compost you need to fill a bed I’ve added a raised bed compost calculator on the linked page.
Maintenance and amendments
Raised beds need regular topdressing with organic matter to maintain nutrient levels and soil structure.
I don’t see the issue with this. So does any soil if it is to remain healthy and contain nutrients for the crops grown. We can’t keep taking from the soil without putting something back!
Once constructed, raised beds are not easily moved, restricting flexibility in garden redesigns. Not so if gardening on the flat.
Potential for soil drying out
Raised beds may dry out more quickly than in-ground gardens, requiring more frequent watering.
Agreed. We cant have better drained without this problem. Not only are raised beds more vulnerable to drying out by the wind passing over and around them, they also catch the sun more and therefore dry out faster.
Increased risk of insect infestations
The enclosed space of raised beds can create favourable conditions for insect pests, necessitating vigilant monitoring.
Slugs tend to snuggle down in the space between the raised bed and the soil or compost. They love it here. I know some people say raised beds decreases the risk of carrot fly so that’s a plus, but I’ve seen carrot fly damage on roof gardens, so I don’t necessarily buy into that one!
Advantages & Disadvantages Of Raised Beds: Conclusions.
Whether they are good or bad, the Advantages & Disadvantages Of Raised Beds are many. There is no right or wrong answer to whether you should have them. It is a decision for each of us to make as individuals. Personally I think they are more trouble, effort and expense than enough, but I know there are people that swear by them. Decide for yourself.
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