When to Build Raised Bed Vegetable Garden Planters

To determine if you should build raised bed vegetable garden planters, it’s necessary to first understand the benefits and drawbacks of such gardening techniques. Not just in general, but in regards to how they will interact with other factors such as the plants you are going to be growing, your climatic and soil conditions, as well as how much time and effort you want to spend on your garden. By carefully considering these types o interactions, you can best determine if raised bed vegetable planters are right for your situation.

To some extend this is going to depend on which raised bed vegetable garden plans you end up going with. This will impact both the time and energy that you spend in implementing the plans, as well as the benefits that you can expect from them.

Cost to Benefit Analysis

Building raised beds can be a major undertaking for larger gardens. The benefits of doing so need to be weight against the extra work and materials that will be necessary to make it work. Of course there are also harder to evaluate concerns, such as how it will impact the way the garden looks, which can of course be a very important thing.

Some raised bed gardening plans call for using boards to keep the soil in place. This can be a major cost for the lumber, and one which may have to be done over and over again as the wood will rot over time and need to be replaced. Other raised bed designs simply rely on piling the soil up into mounds, which saves on material costs, but can lead to the beds “falling” back over time. Regardless of which method you choose when building raised beds, your garden needs to be able to pay back the expenses that you are putting into it for it to be a useful addition.

Main Benefits of Raised Beds for Vegetables

With raised beds you are first and foremost promoting deep, loose soil for your vegetables to grow in. This is exceedingly important for some crops like carrots, onions, and other root crops. Some other vegetables are not as affected by the depth of the soil as they have rather shallow root systems. Tomatoes, peppers, eggplant and other similar crops fall into this category. While they do have extensive root systems, they tend to be only in the first few inches of top soil, spread out horizontally rather than drilling down vertically.

That doesn’t mean that such plants can’t benefit from raised beds though. With raised beds you are also promoting soil drainage. This is important because while plants need water, they also need good aeration for their root systems to properly function. For this reason very few vegetables will survive very long when there is standing water where they are planted. Some plants, like eggplant, can tolerate flooded conditions for a few days, but even they will succumb after a rather short period of time.

By building raised beds for your garden, you are protecting against this sort of thing from happening. The water table will be lower down in relation to the roots of the plants, and standing water will naturally be directed away along the walkways between beds.

The nature of the walkways is another benefit for raised beds. This can facilitate flooding the garden as a form of irrigation, which is often the most efficient manner when there is ample water and a relatively flat garden. In dry times too there is a benefit from having the plants at a higher level than the walkways. This will help to improve airflow underneath the canopy of the plants, which is important to promote good health of the plants and to allow predators to the pests that feed on the plants to more easily spot their prey.

Drawbacks to Raised Beds for Growing Vegetables

With all the benefits to working with raised beds for vegetables, it’s important to note the potential drawbacks. Simply building raised beds to grow your vegetables in due to them being “better” can lead to cases where you are actually undermining your crops ability to be productive. This sometimes happens in dry areas where there isn’t a lot of rainfall, and restrictions on irrigation as well. In those cases it’s often better to plant in furrows (eg. deeper) than on raised beds, simply so that the root zone of the plants is deeper, where there will be more water.

In other cases you may just be increasing your workload for no real benefit at all. This can be the case in dryer climates and / or with loose soils like sandy ones which are already very well drained. By building up raised beds, you are moving the root zone of the plants up in relation to the water table. This will mean that, all else equal, the root zone will be dryer than if you hadn’t used a raised bed. The end result is that you may very well have gone through all the effort of raising the bed, simply to increase the amount of irrigating that you need to do.

That doesn’t mean that in all cases it’s better to not use raised beds if you have well drained soil though. Sometimes such soil is pretty thin, and it can make a lot of sense to build it up to better facilitate a proper root environment for your plants, especially for those plants which like to have deeper roots or are root crops.

raised beds designs
Charles & Hudson CC Photo

There are also some difficulties with raised beds and erosion in wetter climates. These can be mostly avoided by use of mulches or retaining walls to hold the soil in place. It’s good to understand the potential problems in this regard so that you can properly prevent them from being an issue with your raised garden beds.

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