You’ve probably heard about this amazing supercharged organic fertilizer called compost tea, and you’re wondering can it really be that good? What on earth is it anyway and how does it work?
Well, let’s take a look and find out exactly what compost tea is, we’ll share our simple compost tea recipe, and show you when to use it for a luscious and vibrant garden.
So what exactly is compost tea? Well as the name suggests it is made by soaking or brewing compost in water and then straining off the liquid tea! The water gets infused with the nutrients and beneficial bacteria from the garden compost and this resulting compost tea is a perfect liquid fertilizer and conditioner. It can be applied as a foliar spray or as a drench for the soil, depending on what you need it for.
The Benefits of Compost Tea
You’re probably wondering why compost tee matters. So let’s take a quick look at some of the benefits of compost tea in your gardening.
It is a great addition to just using regular compost. Having a foliar feed can give an almost instant boost to plants and is believed to enhance the flavor of vegetables. If used in an organic garden regularly it can also help to keep the garden healthy and fend off any unwanted pests and diseases. Compost tea contains many good bacteria that can help keep plants healthy.
Fast Acting Feed
By using compost tea you provide a quick injection of nutrients that your plants and vegetable can absorb very fast. I like to think of it as the intravenous drip of my gardening.
Use it as a supplementary feed. I still use the slower releasing organic matter in solid form, manure, compost, green manure. They all have their place and should be used as an overall feeding strategy.
Increased Plant Growth
If you see any signs of weak growth, disease, or perhaps poor weather conditions, the application of compost tea can kick in and provide the corrective action needed for a growth spurt to develop a more resilient plant.
Healthy Stronger Plants
Compost Tea will deliver strong growth and disease resistance in the same way that standard well-rotted compost or manure provides a rich feed for your plants. The main difference is the speed at which the plant can use the tea compared to solid compost material
There is nothing more organic than, well, organic compost. Commercial liquid feeds are often processed using production facilities that use chemicals and more often than not have a large carbon footprint. Taking organic compost, or better still your homemade compost is the perfect way to contribute to a greener planet.
At the same time, you will be allowing nature to do its part, by caring for wildlife and increasing the micro-organism density of your plot, by keeping your growing space chemical-free.
Put simply it’s a much faster and far greener way of getting the nutrients from organic matter into your plant’s system. The liquid is directly absorbed by the plant roots, compared to the very slow release effect of solidified rotten organic matter.
Easy Steep Compost Tea Recipe
Like most things in life, there’s an easy way and a complicated way of doing things. There is no doubt the more complicated things get the better the results, but in my experience of making compost tea, I cannot see that the extra effort has shown itself equally extra results. So I keep things real simple and focus on other aspects of my gardening. So here’s my very simple compost tea recipe.
- 5 Gallon bucket
- 1.5 Gallon of Composting material. Make sure you use well rotten down compost or similar
- 3 Gallons of rainwater. If you only have tap water let it stand for 2 days to dechlorinate
How to Make Compost Tea (Steep Method)
Compost tea can be made in a number of ways and using different ingredients. Experienced growers will all have their own compost tea recipes that they will swear by and may contain many unusual ingredients. The basic choice you have is to buy one of the ready-to-go compost tea systems or to go the DIY method and set everything up yourself.
- Simply place the compost and rainwater into the bucket
- Leave it to steep for two days
- Stir as often as possible, at least three times per day
- Strain off the liquid using an old sack or gauze
- Water your plants…simple
I’m a simple sort of person and I much prefer the steeping method of producing compost tea. It’s super simple and less prone to creating bacterial risk.
DIY Compost Tea Brewer
The DIY compost tea brewer will need to put in a little bit of work to get set up, however, the results can be rewarding. The construction of the brewer and the brewing process if far more technical and will require more effort.
Compost Tea Bucket
There are two sizes to consider when setting up a compost tea brewer for home use, 3 gallons or 5 gallons, anything bigger tends to be overkill. You will be diluting the compost team with water before applying it to your garden, so the result of your brew is a concentrate. Therefore only small volumes are required.
Gauze, or straining fabric
It’s always best to use a gauze bag to hold your composting material. This significantly reduces the risk of clogging the pump or air stone, and also makes replacing the composting material easier to handle.
Aeration is required to allow to bacterial process to take place and it makes a difference to the processing of the composting material. You can use an aquarium pump and some pipework to do this job. It will require a mains power supply.
Air Stone (optional)
To provide a good airflow through the brewing process it is recommended to use an air stone, again borrowed from the aquarium market. Ideally, you should look out for models that have features to reduce clogging from the small particles circulated within the tea liquid as it brews
Drainage Tap (Optional)
A drainage tap or brewers tap allows you to easily pour out the required level of concentrate straight into a watering can or bucket, ready for dilution. This is optional but may be a good idea if you intend brewing on a regular basis.
Check out this PDF guide on how to set up a compost tea brewer. It’s a technical guide supplied by Oregon State University.
How To Make A Compost Tea Brewer
- 5-gallon plastic bucket
- 1 meter or 30”” of ½ “PVC tubing
- 1 x T shaped, slip-to-slip PVC connector
- 2 ½” PVC end caps or plugs
- 1 x plastic or brass ½” barb adaptor
- 1 x female-slip PVC fitting
- Two feet of 3/8” plastic tubing
- 1 x 18w diaphragm air pump
- 1 x submersible water heater, with thermostat
- 1-gallon paint strainer bag or gauze bag
- 1 x 12” long nylon chord
- 1 x elastic or rubber band
- 4 x 12” zip ties
- A hack saw or PVC cutter
- Electric drill with ¼” bit
Compost Brewer Assembly
- Cut PVC tubing:
- 2 x 7½” length
- 1 x 13½” length
- Fix the 2 x 7½” lengths of PVC to opposite ends of the T-connector. Placing 1 x end ½” end cap on one end.
- Fix the 13½” PVC tubing to the vertical end of the T shape T-connector
- Fix 1 x 1/0” end cap to the bottom of the 13½” PVC tube
- Drill a small hole in the endcap located on the 1/2” length of vertical down pipe to allow for air flow down into the liquid whilst brewing. The air hole should be suspended approximately ½” from the bottom of the bucket
- Sit PVC T shaped aerator pipework across the top of the bucket, so each of the horizontal PVC tube pieces are resting on the rim of the bucket.
- To prevent the pipework from moving whilst brewing secure the ends of the pipework to the bucket handles with the zip ties
- Fix the ½” barb fitting to the female-slip fitting
- Place the pump on a level surface at the same height as the top of the bucket rim. It is important to keep the pump above the height of the liquid in the bucket
- Fix the barb adaptor to the PVC horizontal tube
- Fix the remaining end of the tubing to the barb outlet on the aerator pump
How To Brew Compost Tea In A Brewer
Compost Tea Recipe Ingredients
- 2 cups of compost or vermicompost or a blend of both
- 2-4 tablespoons of molasses
- Liquid or granular kelp
- Water (ideally rain water)
How To Make Compost Tea In A Brewer
- Fill the bucket ¾ full with rainwater. Or tap water
- Ensure the aerator assembly in positioned in the bucket. Secured with zip ties
- Attach the pump to the aerator and switch on
- If using tap water, allow the water to aerate for about 5 minutes to dissipate the chlorine
- Place the compost in the strainer bag or gauze bag
- Add the granular kelp to the bag . If using liquid kelp add directly to the water
- Secure the top of the bag with the rubber band
- Suspend the bag from the cross bar of the aerator
- Mix 2-4 tablespoons of molasses to a ½ cup and add to the water in the bucket
- Brew from 12-18 hours
- Remove the compost bag and dispose of content in your compost bin
- Optional: Suspend a submersible heater in the bucket set the temperature to 720 F – 750 F
In its most basic form, you will have a container to which you add water, compost, and molasses. This mixture is then oxygenated using an aquarium pump for 2-3 days to brew. The liquid is then strained off and is ready to use.
Oxygen is the key to getting the compost tea recipe brewing. Make sure you have a constant stream of strong bubbles going through the mixture and give it a good stir from time to time during the brewing process.
The water should be rainwater if possible. If you need to use tap water the pump should be running in the water for a couple of hours before any other ingredients are added to remove some of the chlorine. The chlorine in the tap water may harm the bacteria.
Molasses is added to help provide food for the bacteria and to get them working more quickly. Some recipes will recommend other ingredients, I suggest trying to keep it simple and using what you have to hand.
The compost you use to brew the tea should be of good quality and mature. Compost made from mostly green waste will be higher in bacteria and so best suited for making compost tea, but any good organic compost will do. Worm composting is a great source as this vermicompost is very rich and contains lots of good bacteria.
When making the compost and before using it check the smell. In all compost making, bad smells usually indicate a problem. Good compost should smell earthy and quite sweet; if it smells bad it is a sign that there is not enough oxygen.
For the tea increase the bubbles and for regular compost, you need to mix it more frequently. Do not use compost tea that smells bad, it could do more harm than good to your garden
Using Compost Tea
Once your tea has been strained it should be used as soon as possible. The good bacteria can begin to die off quite quickly without a good oxygen supply so use within a day or two at most. As a foliar spray, it is a great way to give an instant feed to the plants and as a soil drench, it will benefit slow and steady.
Simply pour the tea into the soils around the root system. It will seep down and hold within the soil or substrate and provide rich nutrients to your plants and vegetables.
You can use it anywhere in your garden but also within pots and indoor plants.
You can use the tea as a foliage spray by diluting the tea at a ratio of 1 part tea, 10 parts rainwater. Add a small amount of washing soap to help the tea stick to the plant vegetation.
A pump spray or misting bottle works really well. But you need to make sure you have strained the team to remove any particles that may clog your spray head.
It may be necessary to re-apply to foliage after rain.
The frequency you feed will depend on the plants but an average routine would be to feed once per month during the growing season. For heavy feeding plants up to one feed per week will be suitable, the best system should come from a little testing to see how the plants are growing.
To enjoy the full benefits of compost tea you should stop using all chemicals in the garden. Chemicals such as pesticides can kill good bacteria and so reduce the benefits of compost tea. Of course, this may not suit everyone’s methods.