Knowing how deep to make your raised garden bed can be a confusing task since there are many different reasons for having one in the first place. What you want to grow is the first question you should ask yourself since every vegetable will require something different.
A raised garden bed can be helpful if you have lousy soil or mobility issues. While a shallow bed can be strictly for aesthetics, a deep bed can help with any difficulty bending over. Plants such as melons, root vegetables, and leafy greens are great options for a raised bed.
Whether you have mobility problems or don’t like bending over, a raised garden bed can benefit you and the plants. Having control of the soil composition enables you to make it free of debris that can hinder the growth of vegetables but also make the soil perfect for what you want to grow.
What is the Purpose of a Raised Garden Bed?
A raised garden has many purposes, and the reasons for building one can differ based on each gardener’s needs. For example, some people build raised garden beds because their soil is not suitable for vegetables or other plants. It could be too heavy and compact or too sandy. A raised garden bed lets the gardener pick their soil makeup to grow any plants they want in perfect conditions.
Another reason people may choose to use raised garden beds is because of the available space. A raised bed enables you to maximize your growing area, improve drainage and increase productivity. It also makes gardening easier on the back and knees since you can pick the height of the bed instead of bending over to ground level.
When to Build a Shallow Raised Bed
Some people build shallow garden beds simply for aesthetic reasons. However, the height of a shallow raised bed doesn’t matter if the soil underneath is loose and healthy. Roots can grow past the depth of your garden bed and utilize the soil underneath, creating diverse and extensive root systems that then go on to feed your plants.
So essentially, you are just lining the raised dirt for a pleasing look to your garden.
If you plan on only growing greens, then a shallow raised bed would work well. Their roots aren’t particularly long or extensive, so they don’t need all that extra soil to grow. In addition, the raised garden bed would only need to be about 4 inches tall.
Many people use vertical raised beds or something similar to shelves at about 18 inches deep for their leafy greens. Keep in mind that a shallow raised bed will dry out more quickly and will require more frequent top-ups with watering.
When You‘ll Need a Deeper Raised Bed
Higher-raised garden beds are great for those with accessibility issues. For example, they help with issues of bending down or kneeling when people have problems with their knees. Older people also benefit from having higher garden beds, so they don’t have to bend as far down or risk not being able to get back up again.
Even those in wheelchairs can benefit from a raised garden bed, as they don’t have to sit on the ground. Many people have elevated beds that stand on legs, allowing wheelchairs to move alongside the edge. Gardening is a great hobby and being able to participate, even when suffering from mobility issues, could keep people in the hobby or even introduce them to something new.
Higher raised beds also offer plenty of room for plants, especially those with extensive root systems or root vegetables. However, keep in mind the higher the bed, the more expensive it will be to fill.
Which Plants Grow Best in a Raised Garden Bed?
Greens like lettuce, spinach, and kale do great in raised garden beds. Their shallow roots don’t need a deep bed and can be planted as soon as the ground thaws. Also, since they like cooler soil, they are the first vegetables you can plant in the season.
The soil in a raised garden bed will also thaw quicker, giving you several more weeks of growing time and possibly getting several harvests.
Leafy greens hate soggy roots, and their biggest killer is root rot; when the soil is constantly wet, their roots rot. A raised garden bed offers excellent drainage, making it ideal for growing your greens.
Carrots, beets, radishes, and parsnips are perfect for raised beds. However, because the harvestable vegetable grows underground, the soil must be in perfect condition. This means it needs to be free of rocks, tree roots, and other debris that can hinder vegetable growth and cause it to become misshapen.
Like root vegetables, potatoes are a great candidate for a raised garden bed. They are substantially easier to harvest since you can control the hills you planted your potatoes in and even create a bed you can add to as the plant grows.
Potatoes require loose, loamy soil with excellent drainage so the potatoes don’t rot before you can harvest them. A raised garden bed is perfect for this situation and provides ample room for them to spread out easily.
As a bonus, potatoes tend to have higher yields with bigger tubers than if they were planted in a regular ground garden.
Melons like honeydew, watermelons, and muskmelons do great in raised garden beds. You can even start to harvest them mid-summer; sometimes, the harvest continues for a few months.
The warm spring soil in a raised garden bed encourages the tiny seedlings to push out for early growth so they can size up quickly and begin to flower earlier. At the same time, the loose non-compact soil promotes extensive roots that can flourish and provide for a large plant.
Good drainage in a raised garden bed also helps keep the soil moist but not over-saturated, which can often stunt the growth of young plants.
The only downside to growing melons in your raised bed is they are vining plants and take up quite a bit of room. So if you have the space, designating one entire garden bed for melons could be a good idea.
How Do You Maintain a Raised Garden Bed?
Maintaining a raised garden bed is the same amount of work as if you were using a regular garden on the ground.
- Before planting, you should add nutrients to your soil through compost.
- Ensure you aren’t planting before the last frost and when the soil is thawed and warm. Most plants need warmer soil; thankfully, raised garden beds tend to get warmer earlier in the season than a garden on the ground.
- After your seeds or seedlings are planted, keep the soil moist but not wet, as too much moisture can cause the seeds to rot rather than germinate. However, your little seedlings can mature into harvestable plants with ample sunlight and water.
- Weed when needed, although a raised garden bed makes that process easier, and look out for disease and pests.
- Be careful when planting since overcrowding a raised garden bed is easy when the plants aren’t mature. Unfortunately, when they mature, and if they were planted too close together, air circulation becomes an issue, and your plants can succumb to disease and pests.
- When reusing a raised garden bed the following year, switch out the vegetable families you planted the previous year. Planting the same vegetable repeatedly can drain the nutrients from the soil and cut down on productivity, and eventually make the plant wither. Rotating which crops are planted is key to maintaining plentiful harvests.
Maintain the Wood
Another thing to note is the wood type. Lumber will tend to degrade over time; this is unavoidable but shouldn’t occur for several years. However, that nice brown color of the wood will quickly turn into a grayish look as it succumbs to weather and the outside environment.
To prevent this discoloration, finish the wood with a colored stain, paint, or a clear coat if you like that natural color.