Many people choose raised bed gardening because of its consistency and predictability and the solutions it offers to a number of gardening challenges. However there are many valid reasons, especially if you have a larger plot of land, or lower annual rainfall why you may choose to garden in-ground instead.
Gardening in ground is the most well-known type of gardening and has been around the longest, but people began raised bed gardening for a number of beneficial reasons. Let’s discuss first some of the pros and cons of raised bed gardening, and then move on to the reasons to choose one over the other.
Benefits of Raised Bed Gardening Over In Ground:
Complete Control Over Soil
In the ground one area of your soil may have a lot of organic matter, while another area may be completely clay. When filling raised beds you can ensure that your soil mix is consistent across any number of beds. This will lead to more consistent results in your gardening.
In a raised bed you add everything to the bed that the plants will grow in, so you ensure that it is the perfect medium for growing. You don’t control the composition of your native soil. So even though you could add amendments to your soil, you still have less control over the composition.
This complete control over the soil can allow you to crow crops with very specific soil requirements. Blueberries require a higher than normal soil Acidity. It is easier to achieve this in raised beds in areas where the native soil is not useable.
Start Planting Earlier in the Season
There are two reasons why you can get a head start in your garden when using raised beds. Drier conditions and warmer temperatures.
As winter snowmelt and late winter rains saturate the soil it makes it impossible to start your garden.
An old gardener once taught me that in the spring, the proper time to start planting is when you can pick up a handful of soil and it will clump together in your hand, but when you drop it on the ground it will break apart. If the soil is too wet then when you drop it it will land in a glob on the ground and not break apart.
Overly-wet soils create poor growing conditions where you can experience root rot, and undesirable fungi. Also, you will really destroy the soil structure by digging it up while it is so wet.
Because the raised beds are above ground level, more of the rain water drains out of the beds into the soil beneath. So even in the early spring when the soil around the beds is muddy and squishy, the raised beds will be ready to plant.
Being above ground and holding less water also helps the beds to warm up from the sun earlier in the season before the ground does.
Seeds germinate when all the conditions–including soil temperature–are perfect. These warmer raised bed conditions will give you a head-start on planting.
High Intensity Planting
Traditional gardens hold beautiful single rows of vegetables–each separated by a pathway large enough for a wheelbarrow to go down–or at minimum–a person to walk down.
Raised garden beds use a high intensity planting model, where we take the spacing recommended between plants in a row, and give the plants that much space in every direction, but plant multiple rows next to each other.
This creates the appearance of a grid in the garden bed. By getting rid of the space between the individual rows of vegetables–a gardener is able to plant exponentially higher numbers of plants in the same amount of space as the traditional garden.
There are additional benefits to this high intensity planting model. The plants themselves act as a sort of living mulch, helping to prevent nourishing sunlight from getting to weeds and helps retain moisture in the garden bed.
Avoid Wasting Amendments or Materials
Many people find it necessary to add amendments to their garden–whether that be sand or peat moss or compost or other fertilizer to help promote satisfactory growth.
The traditional model of gardening is very wasteful in this respect. Amendments are spread across the entire growing space and tilled into the ground. But only a portion of that is in the soil that will actually hold a plant.
In a raised bed garden, you will only add amendments to the raised garden beds. None of the amendments will be wasted in the aisles or walkways. This also helps avoid the environmental impact of fertilizer runoff.
This same principle affects using things like row cover, insect netting or greenhouse plastic. You can get more plants covered with less material than traditional rows.
Structural Benefits
There are a few benefits to be had from the actual structure of a rigid raised bed.
Raised beds which are constructed with sides out of lumber, stone or metal can be any height you desire. This makes raised bed gardening ideal for people who are unable to bend over to tend a traditional garden. People using wheelchairs, or the elderly are often able to garden in a raised bed built to fit their needs.
Raised beds with rigid sides can also be constructed with either a rigid bottom, or a screened bottom using hardware cloth. These garden beds will help keep out burrowing animals such as moles and voles. This may be the only way gardeners with this type of animal pressure can successfully garden.
Non-compacted Soil
Having the raised beds distinct from the path ensures that the planting area does not get stepped on. Stepping on the soil compacts it and makes it harder for the roots of your crops to grow.
For this reason many people build raised beds no longer than 12 feet so the gardener will never be tempted to step in the bed to get to the other side instead of going around. For the same reason others suggest only making beds 30″ wide so that the gardener can simply step over the entire bed to get to the other side.
Drawbacks of Raised Bed Gardening:
Beds Dry Out More Quickly
One of the major drawbacks of raised beds is that they will dry out much more quickly than the ground. This may be a bigger problem depending on where you live. Most crops grown in the garden need at least an inch of water every week. If this is not provided through rain you will need to have a system for supplementally watering your garden.
Cost of Materials
The biggest drawback to constructing raised garden beds is the cost of materials. Inexpensive raised beds can be constructed out of pine boards. (See my DIY Raised Bed Instructions)
Cedar or Redwood will be more expensive. Stone, brick and metal are also options that will cost more but can be very attractive.
The simplest raised beds can be made by forming mounds of soil that have no rigid side at all. But regardless types of raised beds will need a substantial amount of soil ordered in.
Semi Permanent Nature
One additional drawback to building raised beds is that it would be difficult to move them.
If you want to till up part of your yard and plant a few rows of a garden one year. You could easily reseed that area with grass and move your garden to a different location if you realized it was not the best spot, or you did not enjoy it.
Moving raised garden beds would be in some cases impossible, and in every case a lot of work.
All of these considerations about the pros and cons of raised beds help inform the decision of how to grow your garden. The following indicators about your personal situation can help you determine what type of garden you should grow.
When to Choose Raised Bed Gardening:
- You only have a small plot available
- You have very poor native soil
- You have heavy clay native soil
- You have burrowing animals like moles and voles
- You have trouble bending over to ground level or getting up and down
When to Choose In Ground Gardening:
- You don’t want to put money toward bed construction
- Your native soil is average or good
- You have a lot of land available
- You want to produce on a large scale
- You want to use large farm equipment
