In this article, we will be talking about growbags and the best way to use them to maximise yields and get the best experience from them. Believe it or not, they are not as easy as some people make them out to be.
Let us start by defining what a growbag is?
To answer this question, it depends on where you live. To a person from the UK it is one thing and another to a person from America.
In the UK, a grow bag is a long, narrow, and thick specialised bag full of compost in which plants can be directly grown in them. It is a convenient way for people who do not have ground to grow crops in. It is a container that already comes with its own compost, ready to be planted in.
To an American and confusingly to some Brits, a grow bag is a plastic bag of various sizes in which you yourself have to fill with a compost of your own choosing, Normally, the bag is made out of thick and reinforced plastic where you normally grow crops in. The bag alternatively can be made out of jute but you get the picture that all these bags have to be filled with compost to use them.
The same word used but totally different in their usage; one comes with the compost already supplied and another where the container has to be filled yourself, but both used to grow crops in.
In this article, I will be talking about the British growbag as this is what people in the UK are familiar with.
WHY WOULD YOU USE A GROWBAG?
Growbags tend to be used in areas where you have no soil to grow in, such as decking areas, or patios, or in the greenhouse. Some people have greenhouses that have no beds or bare soil in, but instead, these greenhouses are placed on concrete or slabs.
This is where growbags come into their own, as they can be placed on the concrete and slabs. They are very convenient for gardeners, as you do not have to worry about refreshing the soil in your greenhouse (if you have them) every few years, or to use if you do not have ideal growing conditions.
Idea; for those who want to grow crops in a small area without the need to have proper soil in the ground. Saying that they have developed a reputation of being difficult to grow in, but this is not true as long as you use them right.
WHAT CAN BE GROWN IN GROWBAGS?
Growbags tend to be ideal for growing crops such as aubergine, chillies, tomatoes, sweet peppers, cucumbers, courgettes and lettuce, provided you get the growing conditions right. The problem with growbags is that in hot weather they dry our too quickly and they can get waterlogged if you overwater.
The fact is that competition in the past have driven prices down and bags have shrunk in size, whilst the quality of the compost inside has become substandard. For many manufacturers, this is no longer a problem, as quality has improved, but if you buy a cheaper version then do not be surprised if you get poor results.
They tend to do well when growing salad leaves by cutting the whole top section of plastic off. Lettuce tends to be shallow rooted and so will have enough compost to do well.
The problem is most cheap grow bags are too shallow for tomatoes, peppers and aubergines, but not much so if you buy quality growbags.
TOMATOES NEED ROOM TO GROW
For tomatoes, this is a big problem, as these bags are prone to drying out causing the fruit to split and develop blossom end rot, in particular, if calcium is not available. In my experience, pepper, cucumber, aubergines and chillies will do well, provided you water and feed regularly.
Tomatoes, on the other hand, will need more room to grow and you will need to provide extra compost for the plant to grow in.
To get around the shortage of compost available, you need to buy pots that go directly into the bag. What you need to do is place the pot onto the bag, using it as a template, cut a hole around the plastic, then screw the pot into the bag.
Once the pot is in place you can then fill it with a good quality multipurpose compost mixed with a good sprinkling of slow-release fertiliser. You can then plant the tomato plant into the pot.
HALOES ARE THE WAY TO GO
You can use the good old fashion tomato pots to do this, or you could use modern haloes. The halo also helps in watering and feeding of tomato plants. These devices solve two problems: First, it gives the plants some extra growing space and secondly, it allows the plants to be watered much more easily. This will solve the problem of dry compost bags.
With the halo, you can then add a liquid fertiliser in the water you supply to it so that the hungry tomatoes will get all the nutrients that it needs. As an extra bonus, it comes with 3 anchor slots where 3 bamboo canes can be used to support the plant. It will robustly support the plant as it grows up the canes, especially when it is full of fruit. It can be quite heavy then.
The outermost part of the halo has six, 25mm long spikes, and a reservoir that can hold 3 litres of water. This will penetrate below the surface allowing the plant to get water to the roots. It typically takes 3 to 6 hours for the water reservoir to drain fully depending on how dry the compost is and how hot the weather is.
USE A GROWBAG WATERER
This is okay but you can do better. Tomatoes produce two types of roots: the feeders and the water seekers. The water seekers are the roots that are found at the lower end of the plant, whilst the finer roots at the top are the feeder, where the plant gets its nutrients from. For a healthy plant, you need both types of roots.
If you go on holiday then it will be quite difficult to keep the growbags moist, but if you use a growbag waterer along with the halo, then this will not be much of a problem.
It is the easiest way to grow tomatoes on growbags without the need for automatic irrigation systems. It has a large 15-litre reservoir that can keep plants in water for 14 days. Water is delivered directly to the plant roots through capillary watering spikes that penetrate into the growing bag. This will prevent the compost from getting dry and minimise water wastage.
The water spikes pierce the growbag and it should fit all standard sized growbag. The waterer has an indicator that comes along with it, allowing you to know when the water needs to be topped up or not.
If the water level is running low it can be topped up by using a watering can or you can connect a hosepipe to the hosepipe connector. As an added bonus the base of the device has cane holders, enough to support 3 bamboo canes.
HOW OFTEN SHALL YOU FILL IT
To give an idea of refilling time the following applies.
- If you have 3 newly planted tomato plants of 9cm tall, it will need refilling with water after 14 days.
- For 3, 50cm tall plants will need refilling every 7 days.
- For 3, 150cm tall plants will need refilling every 3 days.
It is easy to use and fill with water. The slit in the bottom of the growbag that is produced by the growbag waterer will allow any excess water to drain out. If these slits are not present at the bottom, the bag can become waterlogged and the plants can die.
What is recommended is that you have the halo on top to provide extra growing space and is a good way of introducing liquid fertiliser to the plant. The grow bag waterer underneath can be used to introduce water to the roots from below. This is a great setup when you go on holiday, but make sure you have a neighbour to pop in once in a while to make sure the plants are not wilting in the hot sun.
In this way, you get the best growing conditions and all bases are all covered.
HOW TO GROW USING GROWBAGS
Usually, you can plant 3 plants per growbag, as long as you use the halo and waterer.
Firstly you need to place the growbag into the waterer, ensuring the water spikes pierce into the bag. Once this is done, you need to fit the halo into the growbags, so that the spikes enter the compost and the rest is above the growbag. Make sure that the spikes of the waterer and halo do not clash with each other, they need to have some separation between them.
Fill the halo with good quality multipurpose compost right up to 2cm from the top. I would also add a sprinkling of slow-release fertiliser to help provide nutrients for the plants and to establish them quickly. The tomato plant can then be planted deeply in the centre of the halo.
BAMBOO CANES CAN THEN BE USED
You can then add three bamboos canes per plant ensuring that the plant can be supported by them. As the tomato plant grows. You can use these canes to ensure the plants does not flop all over the place. The canes should be strong enough to support the plant leaves and fruits without breaking.
Tomatoes need to be watered regularly, especially in hot, sunny weather. This is where the waterer comes in handy, as you can water less often. Water uptake will be frequent in hot, sunny weather, where twice as much water is required than dull, cloudy days.
The compost must be wet thoroughly and not just wet on the surface of the compost. If you water irregularly the fruit sill split and the plant can develop blossom end rot.
You will then need to follow my recommendations on how to grow tomatoes to get a bumper harvest of tomatoes.
The system must be seen as a whole, the halo, the growbag, and waterer, as they mutually work in unison and harmony with each other. You can see the waterer as a way of reducing the watering frequency, the halo as a device to add more compost to allow the tomato plant to grow stronger and a way to add liquid fertiliser. By itself, the compost growbag will not do as well.
In this article, we have discussed how to get the best from your growbags. You do not have to suffer from plants dying because of the lack of water, or because of lack of decent, quality compost. The watering problem is solved via the halo and/or growbag waterer. Lack of compost can be solved via the halo. The devices cover all the bases: watering, feeding, and cane support, so your tomatoes will be at their best.
If you follow my advice, you will get the best from your growbags. If you have any questions that you want to raise or comments that you want to make, please do so in the comment box below.