Growing Cannabis in Raised Garden Beds: A Simple Guide

When it comes to growing cannabis outdoors, the choice of where you plant your cannabis can significantly impact your harvest. Traditionally, growers only think of three outdoor cultivation methods: ground, pots, and greenhouses, but did you know that there’s a fourth option that’s often better than others?

We’re talking about raised garden beds, which combine the benefits of the ground soil and containers while minimizing some downsides of both. Unlike a hydroponic setup, a raised garden bed is easy to make and, pun intended, can “elevate” your cultivation experience. 

But what are raised garden beds and how can you make them at home? Read on to learn all about raised garden beds for cannabis. In this guide, we cover the basics of raised garden beds for cannabis, their benefits for your plants and you, how to DIY a raised garden bed in an afternoon, and some additional tips to keep in mind. 

What are Raised Garden Beds?

Image Credit - CannabisCultivate

A raised garden bed is exactly what it sounds like: a freestanding frame or structure, generally without a base and a lid, that sits above the ground and is packed with high-quality soil. This “bed” acts as a container for your cannabis plants or whatever else you wish to grow there. 

Raised garden beds generally do not include a bottom, so the plant’s roots can still freely grow underground, but the increased height brings many benefits such as fewer unwanted weeds growing there, better drainage and lower erosion, a barrier for pests and rodents, and easier to work on. 

This is why many outdoor cannabis growers, especially if they are not worried about keeping their plants discreet, are choosing raised garden beds more and more. Sure, building one will take an afternoon and some cash, but it is worth it in the long run — for many growers, it’s more suitable than an indoor setup or a dedicated greenhouse! 

What are the Benefits of Raised Garden Beds?

Most outdoor cannabis growers take the usual route of either growing cannabis directly in the soil or using pots. These are simple solutions that work for new growers, but if you want to take your cannabis operation up a notch, it’s worth considering raised garden beds. They offer many benefits that the usual cultivation methods do not, which are as follows.

1. Access to Nutrients in the Soil 

One of the doubts that deter many cannabis growers from using raised garden beds is access to nutrients. Since the plant is grown in the bed, it is natural to assume that it won’t have access to natural nutrients in the soil and you’ll have to add them manually. While this is true for some raised garden beds, it’s not the case with all of them. 

You can have your raised garden bed without a lining to differentiate the soil, which exposes the roots to the natural soil under the plant. This way, your cannabis roots get to benefit from the soil amendments you add to the bed as well as the nutrients present in the soil underneath — a win-win situation. 

2. Better Drainage 

In some regions, especially with heavy rains, regular garden soil can turn into a deathtrap for plants if it rains too heavily — the water may start pooling and drown the roots — and this can happen within an hour if your luck is not on your side. 

But with raised garden beds, you don’t have to worry about your cannabis plants drowning. Because of how they are designed, garden beds offer excellent drainage, which is further improved if you add any alternative growing medium to the soil, and the beds sit above the ground. So whether it is heavy rains or overwatering, your cannabis plant is less likely to experience drowning. 

3. Deters Pests and Small Animals 

Pests and rodents are a nuisance while growing outdoor cannabis plants; they can crawl or critter into your garden and start munching on your cannabis plants. This can lead to all sorts of problems ranging from nutrient issues to physical plant damage, and the rise of pathogens or infections. 

This is another aspect where raised garden beds can come in handy. They sit high above the ground, which is merely a small step up for you, but it is like climbing a wall for many harmful pests and rodents, which prevents them from coming onto your plants and destroying them. 

4. Easy on Your Back 

If you’ve grown any plant in your life, you’ll know the toll it takes on your back and neck (and other parts of your body) if you have to work on it — pruning, cleaning, defoliating, training, etc. — and this only gets worse with cannabis plants since you’ll be spending a lot more time with it. 

To avoid being bent over for hours, despite kneeling down, you can get yourself a raised garden bed. It will take the plant about a foot above the ground, which is more than enough to make it easy and ergonomic to work on your cannabis plants. While other benefits may be good for your cannabis plants, this is perhaps the biggest reason why a grower should consider raised garden beds. It’s more than worth it if you’re planning to be a cannabis gardener for life.

5. Prevents Soil Compaction

If you grow cannabis in the ground, you’ll have to till and work the soil after every harvest to open up the soil as it gets compacted pretty easily, especially if you’ve added soil to the plant. This problem is fairly common in areas with high sand or clay content, too, and this kind of compaction can make it difficult for the roots to expand properly, thereby affecting your plant’s growth. 

So, by using a raised garden bed, you don’t have to worry about soil compaction that much. A raised garden bed is much easier to manage and the soil does not compact as much, and even when it does, it won’t take a lot of elbow grease to till it. 

6. Fewer Unwanted Weeds 

In the garden soil, you never know how many weed (not cannabis) seeds or roots are waiting to start growing, and if you have ever maintained a garden, you know how annoying weeds can be. Not only do they ruin the landscape but they also steal nutrients from the soil, which is why they are such a nuisance. 

But with raised garden beds, you don’t have to worry so much about them. Raised garden beds suffocate the weed seeds and roots under the ground, so they can no longer grow. And even if they are not choked, the garden beds hold all the nutrients above the ground level, with some nutrients leaking below, but the chances are still low. 

How to Build a Raised Garden Bed for Cannabis?

Using a raised garden bed may seem tricky at first, but it is so easy that it is almost always recommended over purchasing a raised garden bed. How easy is it? All you need is a few basic tools, less than basic skills, and an afternoon of your weekend. 

1. Consider the Basics 

Before you start, you need to consider a few things:

Orientation of the Garden Bed 

Your cannabis plant will need a lot of sunlight, so it’s best to position your garden bed facing south or west and away from any shades. In other words, make sure your garden bed runs from south to north for the best sunlight. 

The Size of Your Garden Bed 

You don’t want to build a massive garden bed that’s just hard to reach; instead, your garden bed should be 1.5 meters wide; it can be as long as you want. Having a narrower bed allows you to reach the plant in the center row without bending and tipping over other plants. 

Depth of the Garden Bed 

This entirely depends on the type of plant you are growing, but for cannabis, it is best to have the garden bed at least 8 to 10 inches high. You can go a little over this too if you plan to grow any other companion plants there, depending on which ones you choose, but do not go under 8 inches. 

Pathways

If you want, you can even make a pathway in the middle of your garden bed that will allow you to talk over it and reach the cannabis plants on the interior, too. Ideally, the pathway should be at least 18 inches wide, but you can make it as wide as you want and even grow only two rows of plants — it’s all up to you. 

Type of Wood 

Your garden bed’s frame will be made of wood or timber and this is the most important consideration for this method. Your best bet is pressure-treated softwood sleepers — they are economical and functional — but if you have the budget, you can even go for oak. 

Untreated wood-like scaffold boards or pallets have a shorter life span and are not recommended for raised garden beds unless you treat them with a preservative. Plus, you’ll have to line such wood with compost bags to prevent the preservative from leaching into the medium. 

2. Things You Need 

Next up, you need to gather the things you need to build your DIY raised garden bed for cannabis plants, which are as follows:

1. Durable type of timber as discussed above
2. Canes, string, and spade
3. A spirit level 
4. An electric drill with some coach screws 
5. Topsoil or spare soil from your garden 
6. Sharp sand or other aerating/draining growing mediums 
7. Compost or well-rotted manure 

Remember, the best time to start this project is during the winter months when you have more time and are not growing cannabis plants, but make sure the soil is not frozen over or wet — that will only make things more difficult. 

3. Dig Out a Shallow Trench 

Use the cane and string to draw out the shape of your planned garden map — you can use anything from stones to needles to stakes to mark the four corners. Next, dig out a shallow trench in those exact dimensions, and this trench should be wide enough to hold the timbers. 

4. Position the Timber 

Next, cut the timber into the appropriate sizes — lengthwise — and place them in the trench. Ensure the timber pieces are aligned well with a spirit level and start securing them with a screw. 

To do so, use a drill machine to make two holes through the end timber into the one behind it (known as sleeper timber). Then, use heavy-duty screws to secure the timbers properly. Give it a good shake to see if it’s secure. 

5. Add the Second Layer 

Depending on the width of the timber you used, you may need to add an additional layer of the same to the frame you just installed. When adding this, make sure the timbers on top overlap the joints under them to give the structure some extra strength. If you want to make it even more rigid, you can even screw long screws vertically to prevent the structure from moving around or swaying. 

6. Prep the Base of the Raised Garden Bed 

Next up, you need to remove any turf or grass from the base of the garden bed, i.e., the garden soil. Then, fork the soil to loosen it further. Since our raised garden bed is not too tall, we won’t need to add rubble or subsoil under our beds. 

The next step is to start filling up the raised garden bed. For this, you can use cannabis-specific potting mix — a lot of it — it should be a mixture of compost or manure, sharp sand, and topsoil. These three ingredients should be in a ratio of 3:2:7, respectively, but feel free to adjust the sharp sand quantity depending on the draining levels you want to achieve. 

Fill the bed with this potting mix and let it settle for a couple of weeks and add more if required. After a couple of weeks, you can start planting your cannabis seeds or cuttings in the raised garden beds! 

Raised Garden Beds for Cannabis: Tips, Maintenance, and More Ideas 

The DIY raised garden bed for cannabis guide above is a generic one, but this field of cultivating cannabis is so versatile that you can adapt it to your liking and preferences. Plus, there are some things you must keep in mind for the best results. Let’s take a look at them. 

1. Consider the Alternatives 

While we suggested using timber for making raised garden beds for your cannabis plant, you can even use some other materials instead. If you’re skilled enough for it, you can use stones to construct the walls of your raised bed — this requires big stones, muscles, and a lot of sweat, but it is worth it considering the aesthetic appeal of them. 

An easier alternative to rocks, albeit a bit funky looking, are bricks. They are strong and durable and you can use these to create curved beds that suit your real estate better than straight timber. Use engineering bricks since they are more durable and resistant than domestic bricks. 

You can also use paving slabs by inserting them on their sides to create a wall for your raised bed. You’ll need big slabs and deeper trenches to hold them upright, but they are quite effective although not as good as timber or stones. 

2. Water Your Plant More Often

Raised garden beds have excellent drainage, which is always a good thing but sometimes it can risk your plant from suffering from drought. In this case, it’s crucial to always keep an eye on your cannabis plant’s watering routine and check for signs of thirst. 

Again, the best method here is to use the good ol’ finger test — plunge a finger into the soil and water the soil if the top inch of the soil is dry. Give your plant more water if it’s windy and warm, and if you find your soil to dry out faster, you can reduce the sand ratio and add a layer of mulch on the top, too. 

3. Use Mulch 

Speaking of mulch, it is a good idea to use mulch on your raised garden bed regardless of any watering issues. Mulch will further prevent weed growth while keeping the soil moist cool and free of pathogens. 

4. Don’t Pick the Wrong Spot 

Your cannabis plant will need a lot of sunlight during the day, so you need to pick a spot that gets maximum sunlight. A raised bed isn’t like a pot that you can shift around your garden, you take your time to figure out which area gets the most sunlight and use that. This may not look like a major concern but you’d be concerned to know how many growers make this mistake. 

5. You May Have to Repair the Timber Over Time 

Old timber suffers from saprotrophic fungi, which can rot down untreated wood and soften it over the years. So, you’ll have to keep an eye on the wood and repair it whenever needed. If you ignore this, you’ll wake up one day to find the wood giving way to soil — like a broken dam!

But this spongy wood is not a bad thing for your plant, so it’s not a big deal — it retains water and regulates the moisture content in the growing medium. If you don’t mind an occasional repair job, it’s better to leave fungi wood as is — as long as the fungi are not harming your cannabis plant. 

6. Build a Raised Bed on a Hard Surface, Too

In the guide above, we accounted for a bottom-open garden bed where your plant’s roots can dig into the natural soil, but that’s not mandatory. If you don’t have rich soil in your home or are limited by space, you can even build a raised garden bed on a hard surface. 

A raised bed on a hard surface will act as a big potting container, so you’ll need to place a sheet of compost plastic under it and build the walls with enough holes on the sides for drainage. Remember, waterlogging is a major risk here, so you need to ensure the soil drains easily without choking your cannabis plants. You may need to adjust the potting mix ratios. 

7. Till the Soil Post Harvest 

Once you have harvested your cannabis plants, you should till the soil in your raised garden bed to add more organic matter or compost to the soil for the next season. This will keep your soil rich and you won’t have to keep replacing it after a couple of years of use. 

Summary: Growing Cannabis in Raised Garden Beds: A Simple Guide

As you embark on your journey to become a seasoned cannabis grower, consider using raised garden beds. These elevate your plants and your growing experience with improved nutrient access and drainage, better fortification against pests, and improved ergonomics when working on your plant. 

Building your own cannabis paradise atop these raised structures is not just a hobby; it's a commitment to quality, efficiency, and the sheer joy of watching your cannabis thrive. As the seasons change, don't forget to adapt and refine your techniques. Whether you opt for timber, stones, bricks, or paving slabs, keep the sunlight in mind, monitor your watering diligently, and consider mulch to keep your garden flourishing. And remember, occasional timber repairs are a small price to pay for the countless benefits.

As you harvest your cannabis plants and prepare for the next season, till the soil with care, infusing it with the richness of organic matter and compost, ensuring that your raised garden bed remains a fertile haven for future growth.

So, raise the bar on your cannabis cultivation game, quite literally, with raised garden beds. Elevate your green thumb and watch your cannabis plants flourish like never before. Happy gardening! Stay tuned to our blog to learn more on how to take your cannabis cultivation to the next level, pun intended.