The what, why and how of using vermicompost tea to help your garden, houseplants and yard thrive
What is Vermicompost tea?
Compost teas are extracted from compost using water. The terms compost and compost tea are both broad categories. Compost teas are generally made by mixing compost in water, often with some inputs to improve some of the benefits of the original compost. Compost teas are often made by brewing for some time, usually less than 24 hours. Some preparations of compost teas are aerated, while others are not.
Vermicompost tea is compost tea made with worm castings or vermicompost. Vermicompost is compost made with the help of red wiggler earth worms. Vermicompost is full of nutrients and a thriving healthy microbial community, making it a great soil amendment. One beneficial way to use worm castings, or vermicompost, are to extract the nutrients and beneficial microbes and fungi from vermicompost to create vermicompost tea a liquid that may be applied to soil and plants.
What are the benefits of using vermicompost or worm casting tea?
Compost teas contain a range of beneficial microbial life that will benefit both soil and plants. Vermicompost tea can be used as a fertilizer, microbial inoculant and pest control measure. When applied to plants, it can help with nutrient uptake and growth. Vermicompost tea can also be used as a biocontrol agent against fungal diseases like powdery mildew and root rot. It can also help control pests like aphids, whiteflies, and spider mites. These microbes help with nutrient uptake, disease suppression, and plant growth. This is the best way to get the beneficial biology that is in your worm castings into the soil and root system of growing plants.
How to use vermicompost tea?
The two main ways to apply vermicompost tea is as a foliar spray and as a soil drench. Foliar spraying vermicompost tea is a great way to deliver nutrients and beneficial microbes directly to the leaves of plants. This helps plants fend off diseases and pests, and can help with nutrient uptake. Soil drenching vermicompost tea is a great way to deliver nutrients and beneficial microbes directly to the roots of plants. This helps plants absorb more nutrients from the soil and can encourage growth.
For best results, apply the vermicompost tea in the morning or evening when temperatures are cooler and the sun is less strong. For soil drenches, water thoroughly to get your biological buddies into the soil.
Most importantly: vermicompost tea is alive! It has little to no shelf life. Apply it as soon as it’s brewed.
How much vermicompost tea to apply?
Healthy vermciompost tea goes a long way. For foliar spary, generally, five gallons of compost tea per acre. This is about 1:4 in a watering can with thorough coverage of plant surfaces.
For soil drench, dilute about 1:4 in a watering can a water soil generously to get you biological buddies into the soil, rather than leaving them on the soil surface to dry out.
When to apply vermicompost tea?
Vermciompost is a helpful addition at any time. Here are a few times that a bit of extra worm love would be particularly beneficial:
- before and at time of seeding and/or transplanting; flowering
- during veraison (change of color) and ripening
- at times of vulnerability to pests and disease
- any time during the season to perk things up
It’s also great to use vermicompost tea on a regular basis as part of your integrated pest management strategy throughout the growing season, every two weeks or so. This will help maintain healthy populations of beneficial microbes in the soil and on plant surfaces, and help your plants stay healthy and thrive!
Can you over-apply compost tea?
The short answer is no. There is no harm to applying copious and frequent amounts of healthy compost tea. It’s more economical to apply vermicompost tea than vermciompost, making it more accessible.
When to choose vermicompost tea over vermicompost?
Vermicompost tea is a great way to extend the benefits inherent in vermicompost. The brewing process promotes a bloom of the microbial community. This vermicompost tea can provide an immediate population of microbes to the roots of your plants. Using vermicompost tea is the most economical way to get the benefits to go the farthest in your garden or houseplants. Looking for the cheapest way to get the benefits of vermicompost? Get your hands on some vermicompost tea.
The time to choose vermicompost over vermicompost tea is when the soil you’re working with is lacking organic matter. As a general rule, mix some vermicompost into soil before transplanting or seeding and use vermicompost tea on growing plants.
The other challenge with vermicompost tea is the lack of shelf life. Vermciompost should be stored thoughtfully with access to air, avoiding temperature extremes. Vermicompost tea should be used as soon as possible after brewing and not stored for more than about 12 hours without active aerations. Of course, the solution to this is to store vermciompost and brew it as needed if you’re going to use it frequently.
Does compost tea replace fertilizer?
Vermicompost is a complete fertilizer and soil conditioner. Vermciompost tea is environment where the microfloura are able to thrive and reprodcue. When vermicompost tea is applied to the soil, it helps make the vermicompost more available for plant uptake.
Compost tea does not replace fertilizer, but it can reduce or eliminate the need for some chemical fertilizers, depending on the quality of your vermicompost and the needs of your plants.
The nutrient content remains the same and is diluted from the concentrations present in vermciompost. For this reason, either frequent application of vermicompost tea, or supplementing with another organic soil amendment may help plants with high nutrient needs to thrive.
When is ‘vermciompost tea’ a bad idea?
Beware! Unhealthy vermciompost tea is not benign. When vermicompost tea goes anerobic, things get bad. If you’ve got vermciompost tea that’s no longer fresh, or ended up going anerobic because the brewing didn’t go as expects, consider keeping that funk away from your plants.
It seems like the brewing process is fairly straight forward, but, improperly prepared and handles vermciompost tea can become a home for a bunch of mean anerobic microbes. It can hurt your soil ecosystem.
When vermciompost systems have excess moisture added, they may have a leachate run out of the bottom of the system. This is been covered, but is worth re-stating; some folks have confused leachate from vermciompost systems with compost tea. Part of where this misconception has come from is in the inclusion of a tap at the bottom of some commercially available vermciompost system. This is to allow for drainage without uncontrolled dripping from the bottom of these systems. If your compost system is well managed, there should be little to no drainage. In the context of what you’re putting on your plants… Leachate is not vermicompost tea… Just don’t do it!
How do I get this magic?
You can buy vermicompost tea or make it yourself. If you choose to buy compost tea, make sure you’re getting a live product that is handled as such. The aerobic microbial community in healthy vermicompost tea won’t survive in a closed bottle without aeration. Watch for this when deciding where to buy compost tea or vermicompost tea. Bonus points for finding a vermciomposter that regularly tests their product and publicizes this information.
The process of making your own vermicompost tea is fundamentally quite simple. Mix healthy vermicompost about 10:1 in aerated water for a maximum of 24 hours. There are a few inputs that may be added. In short, this is a complex enough proposition that I’ll add another post about how to brew your own compost tea.
Compost teas are an excellent way to improve plant health, suppress diseases, and improve nutrient uptake. Vermicompost tea is a type of compost tea made with vermicompost or worm castings. It is rich in beneficial microbes that can help your plants grow and thrive. You can use vermicompost tea as a foliar spray, soil drench, or biocontrol agent against pests and diseases. Vermicompost tea is the most economical way to add the benefits of vermciompost often and with great coverage. Give vermicompost tea a try in your garden today!