How To Apply Compost Tea

Apply teas as soon as possible:

Compost teas are alive, and should be served fresh.

  • Compost teas are best if used immediately at the end of a brewing cycle.
  • If your tea sits too long and smells foul discard; in a compost heap, broadcast across the lawn, or away from precious plants.
  • Compost tea should not be kept for more than 72 hours after removing from active aeration.    
  • Compost teas can be refrigerated for up to 30 days.
    • Check them with microscope analysis or your nose prior to use
    • Garden teas such as plant extracts or home brewed fertilizers may keep for longer periods in refrigeration.
    • Allow all teas to return to room temperature and re-activate with stirring or aerating for 1 or more hours.

When to apply compost teas:

  • Apply compost teas when plants and soil are moist
  • Early morning and/ or near dusk, when dew conditions are present will help to ensure that beneficial organisms cultivated in compost teas remain active.
  • For best results apply compost teas monthly or at regular watering intervals.
  • In late winter or early spring:
    • Spray all trees, shrubs, and perennials with fungal dominated compost teas.
    • Again before the formation of flower / leaf buds.
    • Apply when flower / leaf buds break but have not opened.
    • Apply after petals have fallen.
    • Apply a balanced compost tea to all annual beds prior to planting or amending
  • During the growing season: Treat disease such as blight and leaf spot with fungal or balanced compost tea
    • At regular watering intervals.
    • Apply at the first sign of any disease or insect infestation
  • Treat disease such as blight and leaf spot with fungal r balanced compost tea
  • Treat insect infestations with bacterial dominated compost teas.

            Severe illness and infestation in plants are signs of nutritional and biological deficiencies. Plants treated with an organic fungicide or pesticide, to quickly diminish an illness or infestation, should be followed the next day with compost tea. Serving as a pro-biotic for your plants and soils, compost teas will help to rebuild the proper biology and nourish both plant and earth.

How much compost tea do I apply?

With properly made compost tea possessing a diversity of active aerobic organisms, you can never apply too much compost tea.

  • For best results use teas at full-strength.
    • A full-strength tea will possess the maximum active biological diversity or nutrition content and be most effective
    • Compost and garden teas can be diluted at any ratio up to 10:1
    • Repeated applications of compost teas will only help to increase the diversity and populations of beneficial microbe
    • Root drench; apply 5-10 gallons (full-strength or diluted up to 10:1) per 1/4 acre
    • Foliar spray; apply to the point of runoff
    • Field spray; apply 5 gallons across up to 2 acres

How To Apply Compost and Garden Teas:

Soil Drench

  • Apply as a soil drench or root dip when transplanting.
  • Apply at regular watering intervals for outstanding results.
  • Apply from the base of plant as far out as the plants drip line or root mass.
  • Use plastic watering vessels as bacteria can eat-away at the zinc in metal.

Leaf/ Foliar Applications of Compost Tea:

    • Use a clean hand pump or pressurized sprayer
      • Use a diaphragm type sprayer
      • Use a Solo brand or equivalent backpack sprayers

    • If using a Gilmore or equivalent brand 2-gallon type of handheld sprayers we suggest upgrading the sprayer wand with a more durable and versatile sprayer wand.
  • Do not exceed 70 psi (slow dispersion is better)
    • Most hand pump and diaphragm sprayers will not exceed 70 psi.
  • Spray Pattern should be wide and gentle with no hard splattering
  • Teas should cover at least 70% of the leaf surface for maximum effectiveness and remain moist for 15 minutes or longer
  • Avoid spraying open flowers and fuzzy-leafed plants, like African violets.
  • In dry conditions, spray teas early in the morning or in the evening to allow the organisms in the tea to remain moist and active after application.

Best time of day to apply compost and garden teas.

  • Ultraviolet rays from the Sun can also be harmful to microbes. It is best to apply teas before 10:00am or after 6:00pm regardless of cloud cover and the time of year.
  • Moist and misty mornings or after rain is an excellent time to apply compost teas.


Clean your brewer, air diffuser, watering vessels, and/ or spray applicators immediately after each batch of tea or application

  • Thoroughly clean brewer bucket, air hose, air diffuser and spray applicator after each batch of tea.
  • Use dish soap and a scrub brush to clean all residue known as bio-slime from all of your components before storing.
  • The air-diffuser included with our Garden Tea Brewer can be safely cleaned in the dishwasher.
  • Hydrogen Peroxide can also be used to sanitize your equipment.
    • Hydrogen Peroxide will kill many microbes and using it with dish soap and warm water works as a thorough cleanser.
  • Baking soda can be used as an abrasive cleanser.
  • “No Rinse Cleansers”, such as One-Step, used to sanitize bottles and equipment for the home brewing of beer and wine making works well to sanitize your equipment.