# Biodynamic Horsetail Preparation — Equisetum arvense (BD 508) — Spray Preparation

### One unit is 1.5 ounces.

## At a Glance:

**What it does:**  
Helps regulate water processes. Controls and prevents fungal diseases by supporting fungal balance in the soil.

**How to use:**  
Boil into a tea and spray to manage fungal conditions.

**Ingredients:**  
Horsetail (_Equisetum arvense_).

🌾 [Learn More about BD508 Horsetail (Equisetum)](https://go.jpibd.org/guide-bd-508 "BD 508: Equisetum: The Lunar Healer of the Compost")

**Option 1:** Dry Equisetum (1 unit, 1.5 oz)

**Option 2:** Fermented Equisetum (1 quart)

## Product Details:

BD 508 can be used for soil or foliar applications, especially when conditions are too wet. It helps discourage fungal disease. One unit of the dried herb makes one fresh-tea batch, enough to treat one acre, or 10 gallons of fermented tea, enough to treat up to 3 acres.

**Fresh Tea Instructions for BD 508** Bring one unit (1.5 ounces) of horsetail herb to a boil in one quart of water and simmer gently for one hour. Allow to cool. Strain and dilute by adding 2 gallons of water. Stir vigorously for 20 minutes. Apply using a fine mist spray to the foliar parts of targeted plants.

**Fermented Tea Instructions for BD 508** Bring one unit or 1.5 ounces of horsetail herb to boil in one gallon of water and simmer for one hour. Let cool and transfer to a crock or other storage container with a loose-fitting lid. Store this in a cool place, e.g. basement, and allow to ferment for 10 to 14 days, until the fermented tea has a strong sulphuric aroma. Strain the remaining herb particles out, fill the tea in a glass jug, and store it in a cool dark place until ready to use. It can be stored for 6 or more months without losing effectiveness. To use, add 1/2 gallon of fermented tea to 4 1/2 gallons of water, stir vigorously for 20 minutes, and use to treat up to 1 1/2 acres. One unit of horsetail can thereby treat up to 3 acres with as powerful effect as can be achieved by the fresh tea recipe on only one acre. The ratio for diluting is one part fermented tea to 9 parts water.

The fermented BD 508 should be applied as a soil spray, whereas the fresh tea version is the form used as a foliar spray.

**One-quart fermented concentrate option:** Dilute the full quart with 2.25 gallons (9 quarts) of water, stir vigorously for 20 minutes, and apply as a soil spray to up to 0.75 acre.

* * *

**BD 508 Detailed Usage Instructions: [English](https://go.jpibd.org/instructions-bd-508) | [Spanish](/pages/making-using-bd-preps#spanish508) | [Chinese](/pages/making-using-bd-preps#chinese508)**

**Additional Article: [BD #508 JPI Horsetail Fresh Tea and Fermented Tea Instructions](https://cdn.shopify.com/s/files/1/0017/4473/2221/files/BD-508-JPI-Horsetail-Tea-Instructions.pdf?11510486555095028812), [Brief Instructions: 500, 501, 508](https://cdn.shopify.com/s/files/1/0017/4473/2221/files/500_501_508_Brief_Instructions.pdf?337)**

**Please note: Quantities over 1 may be bagged together.**

## Details

- **Price:** 6.51 USD - 14.5 USD
- **Vendor:** The Josephine Porter Institute
- **Type:** Spray Preparations
- **Tags:** farming, gardening, Gardening and Agriculture, orcharding, soil remedies, Spray Preparations

## Variants

| Variant | Price | Available |
|---------|-------|-----------|
| Dry Herb (1.5 oz per unit) | 6.51 USD | In stock |
| Fermented Liquid Concentrate | 14.50 USD | In stock |

## Images

- Biodynamic Horsetail Plant Preparation - Equisetum arvense (BD 508) BD Antifungal Spray Preparation - The Josephine Porter Institute
- Biodynamic Horsetail Plant Preparation - Equisetum arvense (BD 508) BD Antifungal Spray Preparation - The Josephine Porter Institute
- Biodynamic Horsetail Plant Preparation - Equisetum arvense (BD 508) BD Antifungal Spray Preparation - The Josephine Porter Institute
- Biodynamic Horsetail Plant Preparation - Equisetum arvense (BD 508) BD Antifungal Spray Preparation - The Josephine Porter Institute

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> Source: [The Josephine Porter Institute](https://www.jpibiodynamics.org/products/biodynamic-horsetail-preparation-bd508)
> Updated: 2026-08-11