The Ultimate Guide to Grow Bags – Why, Where, And How Should You Use Them?

If you have green fingers, or you're just somebody who enjoys getting involved in the garden during your spare time, you've probably come across many ways in which you can help your plants grow and make things easier for yourself too.

Everybody's garden differs in one way or another – whether it's about the soil, your use of space, or your plants’ exposure to sunlight – so finding blanket solutions to your problems isn’t necessarily plausible.

However, there are some gardening tools and methods that can help in a plethora of scenarios, and one of these things is the use of growbags.

Grow bags offer you an effective method to manage the way in which you space your plants out in your garden, as well as your plants’ water management and temperature regulation, among other things.

I have been using growbags in my own garden for nine years, for a mixture of vegetables and flowers (I grow dahlias commercially in 15 gallon grow bags). I now have more than 600 different ones that I have planted and take care of. So, when I tell you that they have a lot to offer, you can trust that I know what I’m talking about!

Of course, as many fellow gardeners may well know, it isn't as simple as just using any old grow bags; successful grow bag gardening requires careful selection. Grow bags and leaving them to do their thing. Not only do they come in different shapes, sizes, materials, and colors, but there are also several other things you need to know about them and how to use and maintain them in order to be able to really maximize their results.

I'm going to share with you everything you need to know about what growbags are, how to use them, and everything in between. And if you really want to ensure that you’re doing the very best for your beloved plants and garden, make sure you have a look at the additional tips and tricks I’ve included based largely on my own experience.

These include how to ensure your grow bags receive sufficient sunlight, the best way to use fertilizers, and how to deal with pests, among other things.

But first, let's clarify exactly what grow bags are and what their purpose is.

What is a Grow Bag?

In the world of gardening, a growbag is a type of planter that is made from either plastic or a special kind of fabric. Plants are placed directly into the growbag along with the soil, and the entire bag is then placed in the garden.

Certain plants are better suited to the environment that growbags create, including certain vegetables and flowers – both of which I have successfully grown myself – as well as salad greens and herbs.

Essentially, I'd say that plants that don’t have deep roots are the prime candidates for grow bags – that means that pretty much anything that you’d be comfortable planting in a container ought to be okay.

Grow bags for plants have several possible purposes depending on what you're planting and the type of garden you have. For some, a growbag may be the solution to organizing the plants in their garden with regards to space designation. For others, it may be to replace heavier pots to grow plants in outside areas that don't have in-ground gardens.

Of course, a big part of the discussion of the purpose of grow bags is the advantages of using them – and we'll do a deep dive into that soon, along with a few disadvantages and things to consider. But for now, it's important to get a little bit of background to be able to fully understand how and why growbags have evolved the way that they have.

History of Gardening in Grow Bags

First established in the 1970s, grow bags were initially made entirely out of plastic. For many years, they were used in people's homes and gardens, and they were invented to solve a specific problem. That is, back in the day, tomatoes were one of the most popular vegetables for gardeners to plant in their home gardens and little greenhouses.

The issue arose when they needed to be replanted in fresh soil every year in order to give the plant the best chance of survival and to get rid of pests if there were any.

However, uprooting tomato plants is not only difficult and time consuming, but it also wasn't particularly good for the plants, as they don't always do well after being replanted. Indeed, it meant that all the plants would need to be uprooted, and the soil would need to be disposed of and replaced with fresh soil.

In fact, commercial growers would need to go as far as steaming and sterilizing the areas just to be safe before introducing their plant bags. It came down to the fact that the entire process was time-consuming and expensive, and it simply wasn't feasible for small-scale growers.

Thus, the idea of growbags was born. They represented a way to solve the issue of having to uproot all the plants and dig up all of the soil year after year.

The original growbag was plastic, but it wasn't long before people started designing and producing alternatives that were made from various types of fabrics, including 3 gallon, 5 gallon and 10 gallon options. The reason for the move away from plastic was not only for environmental reasons, but also because fabric introduced the added advantage of being able to facilitate drainage.

That's not to say that only fabric grow bags are used, and their plastic counterpart is a thing of the past – rather, there's simply far more variety these days, not only in materials but also in size and color.

Thus, while they were initially invented to combat a tomato problem, it soon became clear that grow bags had a lot more to offer gardeners than speed and efficiency. In fact, they were able to facilitate the healthy growth of a range of different plants by contributing to effective drainage, spacing, crop rotation, and more.

Here are some of the most important advantages to bear in mind when considering whether or not to use plant grow bags.

Advantages of Grow Bags

The benefits and advantages of growbags are plenty, but some are sure to be more attractive to some people than others. That is, gardeners have different priorities depending on whether they’re working commercially or privately, and so on.

With that in mind, here are some of the most important advantages of gardening grow bags.

Extra and Better Use of Space

By using growbags, you can make better use of your space in your garden and keep your plants organized. They're particularly helpful in this regard if you’re hoping to start a successful succession planting program.

Temperature Regulation

This applies to non-plastic varieties only, but fabric grow bags are great at helping to regulate the temperature of your plants. Plastic pots can get very hot in the sun, often causing plants to overheat if they spend prolonged periods in direct sunlight. However, the fabric used to make certain types of growbags are breathable, allowing hot air to escape and encouraging healthy airflow.

Better for the Roots

When it comes to pots – plastic or otherwise – the shape often leads to the plants' roots becoming coiled. That is, they grow in a circle due to the shape of the pot, a phenomenon called rootbound, which can be mitigated by using non-woven grow bags.

However, the flexible shape of grow bags allows the roots to grow more naturally which is better for the plant's overall health.

If you really want to prioritize root health, however, fabric grow bags are the best option, and not only because of their flexibility. Another contributing factor to the issue of rootbound, specifically in plastic pots, is that the roots grow to the edge of the plastic and continue to grow in a circle round and round the container until eventually, the roots are tangled and bound up.

Fabric grow bags can counteract this problem since the fabric itself is breathable and allows the roots to be exposed to fresh air without humidity - unlike in plastic pots. This exposure of the roots to air is called air pruning, and essentially, it prevents the roots from growing infinitely - thus, they don't end up growing long and forming a circular shape that eventually ends up in a big tangle. The roots are able to grow out and down without becoming restricted - therefore, your roots are far healthier.

Easy to Store

Whether they're empty or being used, fabric grow bags are easier to store than plastic growbags or pots, making them easier to transport and store at home or at your business.

Some are Eco-Friendly

Of course, grow bags are available in several different styles and are made from different materials, so this isn't true for all of them. However, some of the fabric versions are biodegradable, so if you're looking for something you won't have to remove and is also good for the environment, this may be the perfect gardening in grow bags solution for you.

The other, arguably better, option is grow bags that are made from recycled poly propylene. Not only are they made from environmentally friendly and sustainable materials, but they’re also bpa-free, super durable, and long lasting. Furthermore, they're breathable, allowing for air pruning which contributes to plants' root health and overall ability to grow successfully.

They Can Be Used Anywhere

One of the best things about grow bags is that they allow you to plant things you wouldn't otherwise have been able to grow – whether that's due to poor soil or not having appropriate exposure to sunlight.

Thus, you can plant vegetables, flowers, or whatever it is you desire in a growbag and position it in such a way that suits you and the plant bags. You can move them as the seasons change or even during the day if your plants aren't getting enough sunlight. Essentially, growbags allow you to make sure that your plants are perfectly positioned.

Attract Pollinators

Attracting pollinators to your garden is an excellent way to really get a healthy environment going, and you can use growbags to facilitate the process. You can do this by planting different colored flowers in a series of different bags and scattering them around the garden to attract pollinators.

And, if you feel you need to attract them to a specific part of your garden for some reason, you can simply relocate the growbags.

Better Drainage

Both plastic and fabric varieties allow for good drainage, but the latter would be the best if drainage is your priority. Since the material is porous, the plant won't be relying completely on specific holes in a plastic bag.

Easy Harvesting

Since you can easily remove the entire bag in one swift motion, harvesting your plants will be significantly easier than having to dig up individual plants – especially when you don’t know where one stops and the next one starts. Grow bags will save you time and effort during the harvesting process.

Easier to Work With

If you're a passionate gardener, then spending time working with your plants and hanging out in the garden is sure to be one of the best parts of your day. And, if you're spending a lot of time out there, it can become a bit uncomfortable to have to constantly bend over or work with plants in the ground.

However, one of the most practical advantages of grow bags that I've found, when it comes to doing actual gardening, is that they’re a little higher offer the ground. Therefore, you don’t have to bend as much and it's just easier on your body in the long run!

Crop Rotation

Crop rotation is a very important part of looking after your crop families properly. Ideally, they ought to be on a four-year rotation schedule – that is, every year, they need to be moved to a different flower bed until they return to the first one in the fourth year.

The reason for this is that if you were to keep in the same place year in and year out, your crops will become susceptible to soil-borne pathogens. However, if you use grow bags instead, you won't need to have access to endless space in order to effectively rotate your crops. Rather, you can achieve the same result by replacing the soil with clean soil that isn't filled with years’ worth of pathogen build up.

Types of Grow Bags

As I've mentioned several times already, growbags aren't all the same. They come in different shapes, sizes, colors, and most importantly, they're made from different materials. I'm going to give you an overview of the different types of growbags you may come across and give you some insight into the ways in which these variations can influence the growth of your plants.

Materials Used to Make Grow Bags

The big division when it comes to materials is plastic versus fabric. They both have advantages and disadvantages, but I’ll give you a quick explanation of each.

Plastic grow bags are the original, so to speak. The first plastic growbags, however, weren't the thick, sturdy bags we see today. Rather, they were made from thin plastic and resembled a modern-day plastic bag. Of course, these introduced their own problems - including the fact they weren't breathable or environmentally friendly. They also tended to be made from plastic containing BPA which isn't great for the soil or the plants. However, the reason many people used them - and why some still use them to this day - is because they’re cheap and easy to dispose of.

These days, however, plastic grow bags have evolved into what are more commonly known as growing pots, and they're made from harder types of plastic. They're more sturdy. They're often used to grow things like young fruit and nut trees, things that normally require a harder container or pot.

Fabric grow bags, on the other hand, allow for better drainage and their shape is more flexible, meaning that rootbound isn't normally an issue, which contributes to successful grow bag gardening. They're also more environmentally friendly and allow for better temperature regulation - and these are only a few advantages of fabric growbags over their plastic counterparts and plastic pots! thus, fabric bags are often used for plants that are more fickle, but they’re generally considered the better option for all plants.

Different Colored Growbags

Believe it or not, the color of your growbag actually matters, especially when using light-colored plant bags. Bearing in mind, of course, that since most plastic versions are black, the variation really tends to affect fabric grow bags more.

The color of the bag is an important factor because it affects how much light it’ll let through, as well as the bag’s ability to retain the heat. The general rule is that it's not ideal for roots to be exposed to too much light, and it's good for them to enjoy a bit of heat.

Now, black plastic grow bags are good at retaining heat and don't allow light in. Conversely, light-colored, thin growbags made from fabric are not particularly good at retaining heat and tend to allow the roots to be exposed to light. Of course, the light color is less important if the fabric is thick, because the thickness will contribute positively to heat retention and it’ll allow less light in.

Whether you go with a dark or a light color will ultimately depend on the plant you're growing and what it needs, but either way, make sure you’re aware of the effect of the color of the growing bags you use. Most gardeners, however, will assert that the black bags are generally the best option - colorful grow bags have more to do with their appearance and the overall aesthetic.

Different Sized Grow Bags

When it comes to the size of the growbag you use, it's really all about your chosen plant. Make sure you do your research into how much space the roots require and how big the plant has the potential to grow before you decide on the size of the bag. Indeed, it's essential to remember that it's about both volume and dimension – that is, some bags are wider than they are deep and vice versa.

For instance, you'll probably want to choose a small bag – under two gallons – for small plants that have a diameter less than eight inches and are less than 9.5 inches tall. It's mostly about the roots, of course, so shallow-rooted plants like garlic, lettuce, and onions won't need a particularly tall bag. In fact, for small things like herbs, you may even be able to use 1-gallon growbags.

Potato grow bags, however, are normally at least five to eight gallons large, because potato plants have extensive root systems and require more space. This also goes for things like carrots, Brussel sprouts, peppers, and parsnips – they all have fairly expansive roots.

Thus, whether you're looking for something for a little herb plant or if you need bags for growing potatoes, always make sure you check the size you need first.

There are a few things to consider when purchasing different-sized grow bags, however, and the main one is the cost. The bigger bags can be more expensive, and so it becomes attractive to many gardeners to try and take advantage of bags that are deep to plant more than one plant. However, if you do this with something like potatoes, their roots are likely to become intertwined.

Thus, a good way to be smart about space is to plant one plant with an expansive root system in a big growbag along with something smaller whose roots won’t grow nearly as deep. That way, you save space and money, and your plants' roots shouldn't interfere with each other.

How To Use Grow Bags in Gardening

As with any type of gardening, using growbags effectively requires you to consider all the different factors that affect the process. So if you're wanting to get down to it, here is some advice on how to use growbags in gardening.

What Can Grow in a Grow Bag

You’ll be delighted to hear that they're incredibly versatile – because they come in different shapes, materials, and sizes, and because they can be moved and altered. Just about anything that you’d be able to grow in a container or a raised bed ought to be able to be grown in a growbag as long as you do it properly.

It really comes down to the factors that are always essential when gardening – ensuring adequate watering, access to sunlight, and providing well-draining soil. If you can meet these criteria, you should be good to go.

Another top tip, if you'd like to increase your success rate, is to try and stick to plants that reach maturity reasonably quickly. The quicker they become mature – thus, big and strong – the less chance they have to succumb to the elements.

What to Place Grow Bags On

Part of the beauty of using garden grow bags is that you can place them anywhere, and that's true; grow bags are perfect for small spaces. However, having said that, some places are still slightly preferable to others because they require less additional maintenance.

For instance, the best place for a growbag would be directly in the garden rather than directly on a flat, hard, and dry surface like a patio or a driveway. This is because the former allows the plant (assuming it's a fabric bag) to absorb moisture through the base of the bag and the soil in the garden as well as by means of rain and watering.

However, if your plant is placed on a dry, hard surface, it'll be relying completely on rain and watering, and the base of the plant is likely to dry up and become unhealthy.

Having said this, that doesn’t mean that you can't put grow bags on hard surfaces. It just means they'll need a little extra care and watering at and around the base that won’t be necessary if it were placed in the garden.

Another thing to bear in mind – from a purely aesthetic point of view and because I've seen this happen far too regularly – is that placing growbags on hard surfaces tends to leave stains behind. So, if you’re going to do this, make sure to put something underneath it or are able to clean it regularly.

How to Space Plants When Using Grow Bags

As I mentioned before, it's possible to make good use of space when you're using grow bags, but you don't want to cram them up too much. If you do this, you'll end up compromising their ability to grow, and not only will it affect their root health, but it’s likely that the plants won't get all the nutrients and moisture they need from the soil.

Another problem you may face by putting plants too close together is that this tends to create a favorable environment for pests like aphids, too many of which can be damaging to your plants. However, by creating more space between your plants and providing more air and sunshine, aphid populations will be more limited - not completely wiped out - which will be better for your plants on the whole.

It's important that you have some aphids, because they are part of the chain of species that are necessary. Indeed, they are eaten by other larger insects that are actually good for your plants - they prevent even larger insects from damaging the plants.. Thus, if there were no aphids at all, the larger, beneficial insects would struggle and the even bigger ones would be free to run rampant in your garden. Thus, the moral of the story is that placing your plants too close together can throw off the natural balance of aphid populations.

If you choose to plant more than one plant in a single growbag, that’s okay – but make sure it's a large bag and don't exceed three in one bag. If you have one plant with an extensive root system, don't plant another one that is similar in the same bag – rather, choose something gentler and with shorter roots.

Don't plant them too close together and also ensure that they're not right on the edge – try and leave enough space for at least one other little plant in between yours and the edge of the bag.

What Type of Soil Should be Used with Grow Bags?

The type of soil you use is always important in gardening, and it's no different when you use growbags. Most importantly, they require well-draining soil that can properly retain moisture. Things like container mix or potting soil tend to tick these boxes.

Perlite is a substance added to some soils that helps with moisture retention, so keep an eye out for that in the ingredients. There are several other things that the soil may contain for different purposes, including things like coir or vermiculite, so make sure you check the ingredients and do some research.

When it comes to replacing the soil in your grow bags, it's important to know that you don't actually need to completely toss it out every year. The exception to this, however, is if you find evidence of a soil-borne disease – you can have your soil tested for this. If you do find that your soil contains something like this, you will need to toss it all out and start again.

However, if the soil is clear, the best thing to do is to toss it all into a wheelbarrow and leave it to expand for a while. Before replanting your plants, add some fresh soil to the mixture – you should end up with 75% old soil and 25% fresh soil. However, the 25% new soil oughtn’t just be plain soil; it should be a successful grow bag mix for optimal results. Rather, it should be new soil mixed with compost and a mixture of fertilizers to replace the nutrients lost in the previous growing season. If you don't add the compost and fertilizer, you'd simply be increasing the ratio of components that cannot decompose which is unhelpful for the plant.

This method, if done correctly, allows you to save money by not having to purchase new soil entirely while still providing your plants with enough nutrients to grow and thrive.

In terms of compost and fertilizer, it’s not recommended to place a plant directly in compost because it simply doesn't have everything a plant needs to thrive. Rather, use a soil mix that contains a bit of compost and consider incorporating an irrigation system for better moisture control. And if you'd like to use a fertilizer, try and opt for a liquid or soluble product – these tend to have the best results.

How to Water Grow Bags

You must water your plants regularly when they're in growbags because they may dry out reasonably quickly – this depends on the material, color, size, and location of the bag, of course. Either way, make sure you keep a close eye on it and if you've placed it on a hard surface, make sure you monitor the bottom of the plant too so it doesn't completely dry out.

Ensuring Your Grow Bags Get Enough Sun

The amount of sunlight your plant requires will depend on what it is – whether it's a flower, a vegetable, a herb, or whatever else – so make sure you know what your plant needs.

The nice thing about having a garden growbag for your plants, however, is that you can simply move them around as much as necessary. Thus, if you realize that your plant is only getting about four hours of sunlight during the day rather than eight, you can simply move it around the garden to follow the sun to ensure it gets enough sunlight.

Grow Bags Versus Pests

One of the nicest things about growbags is that they actually tend to attract fewer pests because they're isolated. That is, rather than having an entire flower bed that could be the source of the pests, the growbag is on its own and the pests can't get into it as easily.

That's not to say that they never do, however. Some types of bags have little flaps that allow you to peer in, which can be handy for monitoring aeration. But even if they don't, just make sure you keep an eye on your plants as you would anything else in your garden, and if pests do begin to become a problem, make sure you take care of them quickly.

How to Use Supports with Growbags

Supports are incredibly effective when used in conjunction with grow bags, as growbags can be moved into just about any desired position. You can use panels to create a vine-type situation and place the growbag in front of it. Or you could even use something like a tomato cage.

One of my personal favorites is supports made from bamboo products. There are several reasons that they're the best material available, including the fact that they're harder and stronger, less permeable than other materials and aesthetically pleasing.

A few options for different types of supports, all available in bamboo, are poles, hoops, trellises, and ladders.

Summary

If you're considering using grow bags for plants, my suggestion is that you should go for it. Just like any plant, you'll still need to pay close attention to looking after it, but this method simply makes it significantly easier and more effective to do so. They allow you flexibility and are far more conducive to healthy growth if you do all the right things.

Over 90% of the plants in my garden are in grow bags, and I've found this method to be the most efficient and consistent way to end up with happy and healthy plants. Whether you’re focusing on herbs, vegetables, flowers, or even mushroom grow bags, you ought to be successful as long as you follow all of my tips and tricks.

The best grow bags are the ones in your garden.