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Filling Your Raised Beds Right – How To Create Incredible Raised Bed Soil!

When it comes to filling your raised beds with soil, there are a few simple tips and tricks that can really make a big difference in how well your crops will grow inside the beds. Actually, they can make a huge difference!

As more and more people find the joy in gardening, raised beds are gaining immensely in popularity. Not only are they great for small yards where a traditional garden might not fit, they can also be an excellent way for those with health or mobility issues to still enjoy growing.

With their raised design, tending to plants is certainly an easier task. As is weeding, watering and harvesting. But when it comes to how to get the most from your raised bed growing space, what matters most is what is inside of your growing boxes. And we are not just talking about the soil!

raised bed height
Raised beds help ease the burden of gardening by making plants easier to reach. They can be used to grow everything from flowers and vegetables, to herbs, strawberries and more.

To have an ultra-successful raised bed garden, you actually need a few key ingredients. For starters, your raised beds have to be tall enough to hold enough soil for good root growth. They also need to have good drainage as well. Without it, plants can easily rot away as their roots suffocate in wet, soggy soil.

And finally, of course, there is using the right blend of ingredients & soil to fill your bed for growing success. With all of that in mind, today’s article will walk you through the steps of how to load up your raised beds with everything they need to succeed. And, how to keep that soil strong for years to come!

Filling Your Raised Beds – How To Grow Like Never Before!

Selecting The Right Raised Beds – The First Step To Success

Before we get into what to put inside of your raised beds, lets cover the subject of what makes up a great raised bed in the first place.

The fact is, you can create an incredible raised bed from a whole slew of materials. Wood, brick, rock and even metal or plastic can all be used to create beautiful raised beds. But whether you make your own or purchase a ready made unit, the first key is to make sure it has enough height for growing success.

To grow most flowers and vegetables, beds need to be a minimum of ten to twelve inches deep. In fact, for the best chance of success, sixteen or more inches is ideal.

diy raised beds
We created our 18″ high raised bed garden boxes from ordinary 2×6 lumber. Not only are they attractive, but they are also inexpensive to build. And at 18″, they also happen to be plenty tall enough to grow nearly anything.

Anything less than twelve inches (unless growing only herbs) simply won’t allow enough space for good root growth. In addition, the thinner the soil depth, the faster it cools and heats. And when it comes to flower and vegetable plants, temperature fluctuations are never a good thing!

We created 18″ deep raised beds at the farm with inexpensive, non-treated 2×6 lumber. At 18″, the depth is ideal for growing any vegetable or flower, and the height makes working in them a breeze. (See DIY Raised Bed Garden Boxes)

Drainage – The Secret To Filling Raised Beds

Once beds are in place and before you fill, it’s important to make sure they can drain excess moisture. This is especially critical when the beds are placed on concrete, brick or other non-porous surfaces.

There are several method to create good drainage in your beds. One of the best and easiest ways is to fill the bottom few inches with gravel or stone. This allows excess moisture from the soil to drain through quickly.

You can also place slotted drain tile or pipes at the bottom of your beds. Moisture wicks through and into the pipes to drain away. With either method, if your beds are on soil or gravel, the water will drain slowly through the bottom.

gravel for drainage
One of the best ways to ensure good drainage is to add a few inches of loose gravel to the bottom of your raised bed.

However, if you are on a hard surface such as concrete or brick, you will need to drill a hole at the very bottom to allow the water to drain out from the gravel, or a hole for the pipe to drain out. Without a drain hole on a hard surface, the water will simply pool around roots.

Bottom Fill – The Secret To Filling Raised Beds

Now it is time to fill your raised beds. And here is where another big tip to success comes in handy – don’t fill your beds with just soil!

When first filling a new raised bed, in addition to providing a bit of drainage, fill the bottom with a layer of organic matter. Shredded leaves or straw, or a combination of the two are one of the best choices of all.

To add an organic layer, place four to eight inches of material in the bottom of the bed. Don’t worry about the height, it will compact down once the soil is added.

For starters, this adds a little layer of organic matter that roots love. It allows them to expand with ease as they first grow. But it also helps add more drainage too. Best of all, it also saves a bit on the cost of soil to fill it up!

The Right Soil Mix For Raised Beds

Once your layer of organic material is in place, it is time to add the soil. One of the biggest mistakes gardeners make at this point is to add generic top soil or garden soil. Although these soils have their place elsewhere, they are too dense and thick by themselves to work well in a raised bed.

The perfect soil for a raised bed needs to be loose, well-draining and full of nutrients. And the best way to create that incredible soil is by mixing together pulverized top soil and compost in equal parts, and then adding in a bit of perlite and potting soil to help keep the soil even lighter and more workable.

Depending on the size and quantity you need, pulverized top soil can be purchased in bulk or bags. Pulverized simply means that it has been ground down to be free of clumps and chunks of soil.

Mixing equal parts compost (above) with pulverized top soil is the perfect start to fertile raised bed soil. Compost is teeming with the balanced nutrients plants need most.

On the compost side, if you don’t happen to make your own compost, you can purchase it in bags or bulk as well. But whatever you do, add the compost! It really does make all the difference in the power of your soil.

Mixing The Ingredients – The Secret To Filling Your Raised Beds

After layering in a layer of organic matter, start filling in your raised beds with an equal mix of compost and pulverized soil. As you add each, blend them together and mix well.

The compost / soil mix is an incredible combination for sure, but by adding in a bit of perlite and potting soil to the mix, it really helps create a rich blend of nutrients that stay loose and workable.

Potting soil is a loose rich blend of nutrient-filled soil that helps to enrich the soil and compost even more. The perlite on the other hand helps to loosen the mix and aids greatly in drainage.

The mix of pulverized soil, compost, perlite and potting soil is the perfect growing medium for plants inside of raised beds.

As a general rule of thumb, for every 5 parts of compost and soil you add, blend in (1) part potting soil and (1/2) part perlite. As an example, if you are filling your raised beds with 5 gallon buckets, use (5) compost buckets, (5) pulverized top soil buckets, (1) bucket of potting soil and (1/2) bucket of perlite.

This mix really combines the best of the best ingredients. If you want to make your own potting soil, be sure to check out this detailed article on just that subject : How To Create Your Own Great Potting Soil Mix

Soil Longevity – The Secret To Filling Raised Beds

Finally, remember that although you have certainly created great beds for growing, they will need to be rejuvenated each season to keep their strength and power.

This can be done by adding organic matter, compost, or even growing a fall cover crop each year. For more on that, check out How To Rejuvenate Raised Bed Soil on the blog.

In addition to re-energizing your beds each year with nutrients, rotating crops between raised beds can also help keep them productive and disease free. If you have more than one raised bed, alternate what you grow in each bed with each passing season.

rotating crops in raised beds
Vegetables like tomatoes use a lot of resources from the soil. By moving them to a new location each year, you can help keep soil healthy and strong season after season.

Here is to filling your raised beds with amazing soil – and to growing like never before! Happy Gardening, Jim and Mary.

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