Skip to main content

How to Make Nutrient-Rich Compost Tea: A Step-by-Step Guide for Gardeners

December 3, 2023

Welcome to the world of organic gardening, where compost tea reigns supreme as a natural, effective fertilizer. In this comprehensive guide, we’ll dive into how to brew this potent concoction, enriching your garden with all the nutrients it needs.

What is Compost Tea?

Compost tea is a liquid fertilizer made by steeping compost in water. This process extracts and multiplies the beneficial microorganisms found in compost, such as bacteria, fungi, and protozoa. The resulting brew is a highly effective, organic plant food and soil conditioner. Compost tea not only delivers essential nutrients to plants but also helps to improve soil structure, increase nutrient absorption, and protect plants from various diseases. It’s an all-natural solution that harnesses the power of compost in a more versatile and accessible form.

Understanding Compost Tea

Compost tea is not just a nutrient-rich liquid for plants; it’s a vibrant ecosystem in a bucket. At its core, compost tea is an aerobic process where microorganisms from compost are extracted into water. These microorganisms, including bacteria, fungi, protozoa, and nematodes, play a crucial role in enhancing soil structure and fertility. They break down organic matter, making nutrients more accessible to plants. Furthermore, they help suppress disease-causing pathogens, promoting a healthier garden. The biology and soil science behind compost tea are fascinating, revealing a symbiotic relationship between plants and microorganisms that is essential for sustainable gardening.

Why Not Just Use Compost?

While traditional compost is incredibly beneficial for garden soil, compost tea offers several unique advantages:

  1. Enhanced Microbial Activity– Brewing compost into tea multiplies the beneficial microbes exponentially. These microbes play a vital role in nutrient uptake, soil aeration, and disease suppression.
  2. Improved Soil Penetration- Liquid compost tea penetrates the soil more effectively than solid compost. This ensures that nutrients reach deeper into the root systems of plants.
  3. Foliar Application– Compost tea can be used as a foliar spray, a method not feasible with solid compost. This direct leaf application can help plants absorb nutrients more quickly and efficiently. Additionally, the microbes in the tea can offer protection against foliar diseases, creating a barrier on the leaf surface.
  4. Easier Application and Spread– Liquid tea can cover more ground more quickly than spreading solid compost. It’s especially useful in large gardens or for those with physical limitations.
  5. Reduced Risk of Burning– Solid compost, particularly when fresh, can sometimes ‘burn’ plants due to its high nutrient concentration. Compost tea, being more diluted, reduces this risk, making it safer for young or sensitive plants.
  6. Resource Efficiency– Compost tea allows you to maximize the use of a small amount of compost, spreading its benefits over a larger area.

Materials Needed

Embarking on your compost tea journey is easier than you might think, often requiring items you likely have around your shed or garage. The essentials include:

  • High-quality compost- The foundation of your tea, rich in beneficial microorganisms.
  • Clean water- Preferably rainwater or dechlorinated tap water to protect the microbial life.
  • A 5-gallon bucket- A common item in most households, perfect for brewing.
  • Cheesecloth or a fine mesh strainer- For straining the finished tea.

While an air pump and air stone are ideal for oxygenating the water, you can still make an effective compost tea without them. If you don’t have these aeration tools, you’ll need to regularly stir the mixture throughout the steeping time to incorporate oxygen. This manual stirring method can still yield a beneficial brew, although it may have fewer aerobic microorganisms compared to a continuously aerated tea.

The Brewing Process

  1. Fill the Bucket– Add compost to the bucket, filling it up to one-third.
  2. Add Water– Pour water over the compost until the bucket is full.
  3. Oxygenate– If you have an air pump and air stone, set them up to oxygenate the mixture. If not, make sure to stir the mixture several times a day to incorporate air.
  4. Brewing Time– Allow the mixture to brew for 24-36 hours. Avoid over-brewing, as it can lead to harmful bacteria growth.
Our How to Video Series – All About Compost Tea

Using Compost Tea in Your Garden

Once your compost tea is brewed and strained, it’s ready to be used in your garden, offering a multitude of benefits for both soil and plant health. The application method plays a crucial role in maximizing these benefits.

  1. Foliar Application- Using a watering can or sprayer, apply the compost tea directly onto the leaves of plants. This method allows the leaves to absorb nutrients more rapidly. The beneficial microorganisms in the compost tea also form a protective layer on the leaves, helping to shield them from diseases and pests. For the best results, use a fine spray and apply in the early morning or late evening to prevent leaf burn.
  2. Soil Drench– This involves pouring compost tea around the base of the plants, targeting the root zone. A key technique here is applying at the drip line of the plant—the area directly below the outer circumference of the plant’s branches. The drip line is where the majority of a plant’s feeder roots are located, making it an optimal spot for absorption. By applying compost tea at the drip line, you ensure that the nutrients and beneficial microorganisms infiltrate the soil where they are most needed, enhancing root health and overall plant vigor.
  3. Tools for Application– A regular watering can works well for smaller gardens or individual plants. For larger areas or for foliar feeding, consider using a garden sprayer. This tool can distribute the tea more evenly and can cover a larger area more efficiently. Ensure that the sprayer or watering can is clean before use to avoid any contamination of the compost tea.
  4. Frequency and Timing– Regular application is key. Apply compost tea to your garden every 2-4 weeks during the growing season for optimal results. Be mindful of weather conditions; avoid applying in the middle of the day or when the sun is at its peak, as this can cause stress to the plants.

By incorporating compost tea into your regular gardening routine, you can significantly enhance the health and productivity of your garden. Whether used as a foliar spray or a soil drench, compost tea is an effective, natural way to provide your plants with the nutrients and protection they need to thrive.

Master gardener tip – always add compost and fertilizers, especially liquids, at the drip line of your plant and about half the width inward to the stem. Most root systems grow outward from the plant and as they extend to the drip line. The roots closer to the plant die back using the newer roots at the tips of the growth. This is the “watering and absorbtion” ring. Applying fertilizer at the stem its not as efficient.

Common Mistakes to Avoid When Using Compost Tea

Properly brewing and applying compost tea is key to its effectiveness. However, certain common mistakes can hinder its benefits:

  1. Overbrewing– Brewing compost tea for too long can lead to the development of harmful anaerobic bacteria. The ideal brewing time is generally between 24-36 hours. Overbrewing may produce a foul smell, indicating that the tea has gone bad and should not be used.
  2. Using Chlorinated Water– Chlorine in tap water can kill the beneficial microorganisms in compost tea. It’s best to use rainwater or dechlorinated tap water. If using tap water, let it sit for 24 hours to allow the chlorine to evaporate before adding compost.
  3. Ignoring pH Levels-The pH of compost tea should ideally be between 6.5 and 7.5. Extreme pH levels can harm the microbial life. If necessary, adjust the pH with natural additives like lemon juice or baking soda.
  4. Insufficient Aeration– Without adequate oxygen, beneficial aerobic microorganisms can’t survive. If not using an air pump, ensure you stir the tea regularly to incorporate air. Poor aeration leads to the dominance of anaerobic bacteria, which are less beneficial and can sometimes be harmful.
  5. Contaminated Equipment– Using dirty buckets, watering cans, or sprayers can introduce harmful pathogens into your compost tea. Always clean your equipment thoroughly before use.
  6. Applying Under Unsuitable Weather Conditions– Avoid applying compost tea during extreme weather conditions like scorching midday heat or heavy rain. Such conditions can reduce its effectiveness and potentially stress the plants.
  7. Incorrect Storage– If you must store compost tea, use it within 24-36 hours and keep it aerated. Storing for longer periods can diminish the beneficial microbial activity.
  8. Overconcentration– If the compost tea is too concentrated, it can overwhelm and burn the plants. Diluting the tea appropriately is crucial, especially when using as a foliar feed.

By avoiding these common mistakes, you can ensure that your compost tea is as beneficial as possible, promoting a healthy and vibrant garden.

Compost and A Sustainable, Organic Garden

Organic and sustainable gardening practices are at the forefront of creating healthier, more resilient ecosystems, both in our gardens and in the wider environment. At the heart of this movement is compost tea, a key player in this green revolution. Embracing compost tea in garden care aligns with the ethos of nurturing the land without resorting to synthetic chemicals. This organic concoction enriches the soil with natural nutrients, bolsters plant health, and fortifies against diseases, all while maintaining the delicate balance of the ecosystem. By using compost tea, gardeners can sustain their plant life in a way that supports the earth’s natural processes, fostering biodiversity and ensuring the longevity of our gardening landscapes. Its role in organic and sustainable gardening is not just about plant nourishment; it’s about participating in a cycle of life that respects and enhances the natural world.

FAQs About Compost Tea

1. What exactly is compost tea?
Compost tea is a liquid fertilizer made by steeping compost in water. This process enhances the microbial life found in compost, creating a nutrient-rich solution. It’s used to improve soil health, increase nutrient uptake, and protect plants against diseases.

2. How often should I apply compost tea to my garden?
It’s best to apply compost tea every 2-4 weeks during the growing season. Regular application helps maintain a healthy microbial balance in the soil and provides ongoing nutrition to your plants.

3. Can compost tea replace my regular fertilizer?
While compost tea is highly nutritious, it should be considered a supplement rather than a complete replacement for traditional fertilizers. It’s best used in conjunction with other organic fertilizing methods for optimal plant health.

4. Is compost tea suitable for all types of plants?
Yes, compost tea can be beneficial for a wide variety of plants, including vegetables, fruits, flowers, and ornamentals. It’s a gentle, natural fertilizer that’s safe for most garden plants.

5. Can I store compost tea, and if so, for how long?
Compost tea should ideally be used fresh. If you need to store it, keep it for no longer than 24-36 hours in an aerated container. Beyond this time, the beneficial microbial activity diminishes.

6. What are the signs of overbrewing compost tea?
Overbrewing can lead to the development of harmful bacteria. Signs include a foul odor, a slimy texture, and a shift in color. Ideally, brew compost tea for 24-36 hours to avoid these issues.

7. How do I know if my compost tea is effective?
Effective compost tea has a pleasant, earthy smell and is teeming with life under a microscope. You should also observe improved plant health and vigor in your garden over time.

8. Can compost tea harm my plants?
When properly brewed and applied, compost tea is unlikely to harm plants. However, using unbalanced or contaminated compost, overbrewing, or applying it in extremely hot weather can cause issues.

9. Do I need special equipment to make compost tea?
Basic equipment includes a bucket, clean water, compost, and a strainer. While an air pump and air stone are recommended for aeration, stirring the mixture regularly can be an alternative.

10. What’s the best way to apply compost tea?
Compost tea can be applied as a foliar spray or a soil drench. When spraying plants, do so early in the morning or late in the evening to prevent leaf burn. For soil application, evenly distribute it around the base of plants.


Compost tea is a fantastic way to nurture your plants and soil organically. It’s simple to make and highly beneficial, making it a staple for any eco-conscious gardener. The versatility of compost tea, especially as a foliar feed, makes it an indispensable tool in the organic gardener’s toolkit. Try brewing some today and watch your garden thrive!

For further reading:

Compost Tea Fact Sheet

Mailchimp Sidebar Signup Form

Subscribe for blog updates