Do Plant Brews Really Work? What the Science Says

If you’ve spent any time on gardening forums or social media, you’ve likely come across homemade plant brews like weed tea, compost tea, banana peel tea, and even eggshell tea or Epsom salts. These DIY fertilizers are praised for being natural, cost-effective, and sustainable—but how well do they actually work? Let’s look at what current research says about these popular garden elixirs.

Weed Tea: Free Fertilizer or Just Funky Water?

Weed tea is made by soaking or fermenting common weeds—such as dandelions, chickweed, or comfrey—in water, with the idea that the nutrients weeds extract from the soil will leach into the liquid and feed your plants. While weeds are nutrient accumulators, there’s little published research confirming the nutrient content or effectiveness of weed tea. Some studies on plants like Tithonia diversifolia (Mexican sunflower) used as green manure show benefits when incorporated directly into soil, but not as fermented teas. At best, weed tea may provide a mild boost, but results are unpredictable and largely anecdotal.

Compost Tea: Some Scientific Backing

Compost tea, particularly the aerated kind (ACT), is one of the most researched DIY fertilizers. It’s made by soaking compost (plant-based or worm castings, not always manure) in water, sometimes with added sugars and oxygen to increase microbial growth. Studies have found that compost tea can improve microbial life in soil, help suppress certain plant diseases, and occasionally increase plant growth. However, its success depends on how it’s brewed and applied. Using fully matured, pathogen-free compost is key, especially when used on edible crops. While compost tea shows promise, it’s not a substitute for nutrient-rich compost or balanced fertilizers.

Banana Peel Tea: Some Promise, If Processed Properly

Banana peels are high in potassium and other minerals. Recent studies suggest that processed banana peel fertilizers can improve soil quality and plant growth. For example, a 2024 review published in the journal Agriculture by MDPI discusses the potential of banana peel-based biofertilizers and their effectiveness when properly processed. Other studies support their use in nano-fertilizer or composted forms for boosting yields and plant health. That said, soaking banana peels in water for a few days may not extract meaningful nutrients. Composting them is a far more effective way to return their value to the soil.

Eggshell Tea and Epsom Salts: Popular, but Situational

Eggshell tea is made by soaking crushed eggshells in water to extract calcium. While eggshells are rich in calcium carbonate, it breaks down slowly. Studies show that unless finely ground, eggshells don’t readily release nutrients into water or soil. Composting or grinding them into powder is more effective. Epsom salts (magnesium sulfate) are also frequently used, especially for tomatoes and peppers. While magnesium is an essential nutrient, overuse can disrupt soil nutrient balance. Unless a soil test shows magnesium deficiency, regular use isn’t necessary and may cause harm.

The Bottom Line: Good Garden Practices First

DIY fertilizers like weed tea, compost tea, banana peel tea, eggshell tea, and Epsom salts can be part of a sustainable gardening routine. However, their effectiveness varies widely, and most are only mildly beneficial unless processed and applied properly. Before adding any homebrew fertilizer to your garden, remember: healthy plants start with healthy soil. Compost and organic matter are your foundation. Always test your soil before adding amendments, it’s the only way to know what your plants actually need. Use DIY fertilizers as supplements, not substitutes, for a well-balanced approach.

Welcome Wildlife with These Attractive Bushes & Trees!

We all feel it—the desire to try harder to coexist with nature. When choosing a new tree for our landscape, we want something that will provide us with shade and beauty plus provide nourishment for our birds and pollinators. We are highlighting three attractive trees that grow well in the Treasure Valley. Each of these deciduous trees are small enough to fit in most yards. They boast beautiful spring blossoms, colorful fall foliage, wonderful fragrance, and bright, edible berries. 

Saskatoon Serviceberry (Amelanchier alnifolia) is a delightful landscape tree, and a favorite among birders in the Treasure Valley. Birds of all kinds flock to the Serviceberry in the summer for the sweet, juicy, red fruit. The berries are edible for humans too, tasting somewhat like blueberries! Billowing white blooms attract bees and butterflies in the spring. When fall arrives, the foliage turns a beautiful, deep red. Hardy in zones 4-9, the Serviceberry tolerates most soil types once established It grows quickly up to 25 feet and prefers full sun.

Choose the Chokecherry (Prunus virginiana ‘Canada Red') tree or shrub if you're looking for something showy that will grow in rather poor conditions. This hardy little 20 to 25-foot tree tolerates heat, cold, wind, and poor soil in zones 2-10. Even though it asks for little, it will grow beautiful clusters of long, white flowers in the spring, attracting butterflies and other pollinators. Each new flush of bright green leaves turns reddish purple by mid-summer, providing striking color throughout the growing season. As the name implies, chokecherries taste bitter to humans when raw, but the fruit can be used to make wines, syrups, and jelly. You’ll have to act fast, though, if you want some for yourself! Birds love to feast on this important and nutritious food source. The leaves and berry seeds are toxic to humans and animals, so do not plant this tree if you have pets that might ingest the seeds or foliage.

A classic in Idaho landscapes, the Crabapple(Malus spp) never fails to delight our winter-weary eyes with its masses of pink flowers in early spring. This outstanding tree thrives in full sun and acidic soil but is quite adaptable to other conditions and is hardy to zone 4. The Malus ‘Indian Summer’ variety has excellent resistance to disease. Crabapples trees are a wildlife magnet. The bright-red fruit remains on the tree from fall through winter as a welcome, nutritious treat.

Martin Luther once said, “Even if I knew that tomorrow the world would go to pieces, I would still plant my apple tree.” 

There is never a better time than now to choose a tree and plant it. Even a small yard can attract birds, butterflies, and helpful insects, benefiting us all for years to come.

With Thrill, Fill, Spill - Container Gardening May Be your Answer!

Want to add color to your landscape without fighting Idaho’s heavy clay soil?

Container gardening may be the answer! More than just for areas with limited space, containers are great for adding height in an existing garden, as a way to plant areas with difficult in-ground soil conditions, or as a portable home for plants that cannot survive the winter months outdoors. They also allow gardeners an opportunity to experiment with combinations of colors and textures on a small scale before taking on a bigger planting.

Additionally, I use container gardens within my own landscape in order to create visual levels of plantings within my border, as well as an alternative to battling digging out and amending the hard clay soil.

Key considerations when gardening in containers: 

1. Location: When determining where to place your containers, it is important to consider the amount of sunlight the location gets during the day. 

2. Container: Containers should have adequate drainage and not be too much larger in size (around) than the combined area needed for the plants that will be planted in the container.

3. Soil: The soil should be mostly a potting soil mix, that can be amended with organic material (compost, peat moss). When adding material to the potting soil, the soil and organic material should be well combined in order to have a uniform texture and allow for proper drainage. 

4. Plant selection: Based on the amount of sun that the container will get during the day, select plants that have similar amounts of sunlight and water required. 

5. For plant recommendations and ideas, check out this article from Oregon State University.

How to Design a Container Garden:

Designing a container garden lets the gardener be free to create playful and eye-catching garden spaces. 

The primary design elements of a container garden are the thrill, fill, and spill. 

1. The thrill is usually a planting that creates height in the container, it is a planting that is often centered in the container and is taller than the rest. 

2. The fill is a plant or plants that are similar in height, but shorter than the thrill. The fill occupies the middle section of the container planting and may have pops of color contrast that draw the eye toward the container. 

3. The spill is typically a trailing plant that spills over the side of the container and adds both drama and texture.   

Trying to decide which is right for you - container gardening or raised beds? Check out these five tips.