When it comes to feeding your window plants, you don’t need expensive fertilizers or synthetic boosters. Sometimes, the best plant food is already sitting in your kitchen—waiting to be brewed. One of the simplest and most effective DIY plant fertilizers is tea. Not for you—but for your plants.
Whether you’re growing herbs on a sunny sill or nurturing leafy houseplants by the window, certain teas can give them a gentle nutrient boost, improve soil health, and even repel pests. This guide explains how and why to use tea as a natural fertilizer, which types work best, and how to apply it safely for thriving indoor plants.
Why Use Tea as Plant Fertilizer?
Tea contains small amounts of essential nutrients like nitrogen, potassium, and phosphorus—all crucial for healthy plant growth. It also introduces beneficial compounds and organic matter that enrich the soil and stimulate root development.
Benefits of feeding plants with tea:
- Natural, chemical-free nutrient source
- Easy to make from leftover tea bags or leaves
- Gentle enough for sensitive window plants
- Supports soil microbes and organic matter
- Can improve foliage growth and color
Best Types of Tea for Window Plants
Not all teas are equal when it comes to plant feeding. Some provide more nutrients, while others offer antifungal or pest-repelling benefits. Here are the top options:
1. Green Tea
Green tea is rich in antioxidants and contains mild levels of nitrogen, making it excellent for encouraging leafy growth.
Best for: Herbs, leafy greens, ferns, pothos, peace lilies
How to use:
- Brew one bag in 2 cups of hot water
- Let it cool completely
- Dilute with 1 liter of water
- Apply to the soil once every 2–3 weeks
2. Chamomile Tea
Chamomile has natural antifungal properties and can help prevent damping off in seedlings and fungal leaf spots on houseplants.
Best for: Seedlings, young herbs, delicate plants
How to use:
- Brew a mild cup (1 bag per 2 cups of water)
- Cool completely
- Use as a foliar spray or soil drench once a month
3. Black Tea
Black tea has more tannins and caffeine, which can benefit some plants in moderation but should be used carefully.
Best for: Established houseplants, flowering herbs like basil and sage
How to use:
- Brew a weak solution (1 tea bag per liter of water)
- Let it sit overnight
- Apply to the base of the plant monthly
Note: Avoid overuse, especially on young or delicate plants.
4. Herbal Tea Blends (Caffeine-Free)
Teas like rooibos, nettle, and peppermint can add trace minerals and improve soil structure.
Best for: General use, especially for herbs and edible greens
How to use:
- Use leftover brewed tea or cooled infusion
- Dilute if the tea is strong or heavily flavored
- Water plants once every 2–4 weeks
What About Used Tea Bags?
Used tea bags can also be composted or buried directly into the soil to break down slowly and feed the roots over time.
How to use tea bags:
- Remove any staples or strings
- Tear open the bag and mix leaves into potting soil
- Alternatively, place the whole bag under the root zone when repotting
Make sure the bag is made from biodegradable material. Some commercial bags contain plastic fibers, which should not be added to soil.
How to Safely Use Tea on Indoor Plants
While tea is gentle, using it improperly can still cause problems like mold, sour-smelling soil, or nutrient imbalances. Always apply it with care.
Safety Tips:
- Always cool the tea before using
- Dilute strong teas to prevent overfeeding
- Never use sweetened or flavored tea
- Avoid teas with milk, sugar, or artificial ingredients
- Don’t apply tea to plants already showing signs of root rot or overwatering
Best Window Plants to Feed with Tea
Tea is most useful for light feeders and houseplants that benefit from a soft, organic nutrient push. Great candidates include:
- Basil – especially with green tea
- Mint – thrives with light herbal infusions
- Pothos – encourages greener, fuller growth
- Spider plant – loves the organic nitrogen
- Peace lily – benefits from gentle feeding and improved soil health
- Lettuce & arugula – can be watered with mild, unsweetened herbal teas
What to Avoid
Not every plant responds well to tea. Overuse can cause soil acidity issues or invite pests if sugar is present.
Avoid using tea on:
- Succulents or cacti (they prefer dry, lean soil)
- Plants sensitive to tannins (like asparagus fern)
- Soilless systems (hydroponics or leca setups)
Avoid applying tea too often. Stick to once every 2–4 weeks, depending on the plant type and size.
FAQs
Q: Can I pour leftover tea into plant pots?
A: Yes, as long as the tea is unsweetened and cooled. Avoid flavored teas, dairy, or sugar—all of which can harm roots.
Q: Is tea better than commercial fertilizer?
A: Tea is a gentle, supplemental feed—not a full replacement for balanced fertilizer. It works best when used occasionally to support healthy soil and foliage.
Q: Will tea attract insects?
A: Sweetened tea or tea with milk can attract ants or gnats. Always use plain, unsweetened tea and don’t overwater.
Q: Can I spray tea on plant leaves?
A: Yes—mild teas like chamomile can be used as a foliar spray. Test a small area first and never spray during direct sun.
Q: How often should I feed my plants with tea?
A: Every 2–4 weeks is enough. Avoid weekly use unless you’re applying very diluted tea or compost-infused water.
Final Thoughts
Tea isn’t just for sipping—it’s a gentle, natural way to nourish your indoor garden. Whether you use green tea for lush herbs or chamomile to protect seedlings, this humble kitchen staple offers a smart, sustainable solution for window plant care.