Homemade Plant Food Recipe for Indoor and Outdoor Plants

Why buy pricey chemical-laden plant food when you can make your own for a fraction of the cost?
Glenda Taylor Avatar
Two houseplants alongside ingredients needed to make homemade plant food.
Photo: Tom Fenenga for Bob Vila

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If you want lush healthy houseplants and garden growth but aren’t thrilled about paying for costly commercial foods with ingredients you can’t pronounce, you’re in luck! You can easily make your own plant food at home for a fraction of the price and—this is the best part—you’ll know exactly what goes into it.

All it takes to keep your favorite plant species robust and beautiful are three common ingredients that you’ll find at any supermarket for around $8 total, if you don’t already have them on hand. Because this recipe requires such small amounts and the ingredients last for months, your cost will literally be pennies per batch.

You may be surprised to learn that the following products possess the properties and nutrients plants need to thrive:

  • Epsom salt contains magnesium and sulfur, both of which are beneficial for plant growth. Sulfur helps plants absorb nutrients from the soil while magnesium increases the plant’s ability to produce chlorophyll, which is responsible for maintaining healthy green foliage.
  • Baking soda stimulates blooms in flowering plants and also reduces the risk of fungal disease. This is especially beneficial for potted houseplants, which are prone to mildew as a result of overwatering and limited air circulation.
  • Household ammonia contains nitrogen, a component that promotes healthy root growth. For plant food, be sure to use plain ammonia, free of other ingredients such as scent or cleaning additives. Remember, ammonia is toxic to people and pets, so be sure to label and store your homemade plant food accordingly.

How to Make Plant Food

Tools & Materials

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Step 1: Measure 1½ tablespoons of Epsom salt into a clean, 1-gallon jug.

Woman uses a measuring spoon to measure epsom salt into a funnel.
Photo: Tom Fenenga for Bob Vila

A rinsed-out plastic milk jug with its lid makes a great container for this homemade plant food.

Step 2: Add 1½ teaspoons of baking soda to the jug.

Woman measures baking soda into a funnel atop a 1-gallon jug.
Photo: Tom Fenenga for Bob Vila

Step 3: Measure a scant ½ teaspoon of household ammonia into the jug.

Woman measures ammonia into a measuring spoon poised over a funnel.
Photo: Tom Fenenga for Bob Vila

Scant means slightly less than the full ½ teaspoon. Don’t overdo it with the ammonia—a little goes a long way!

Step 4: Fill the rest of the jug with plain tap water, screw the lid on tightly, and shake well to combine.

Woman wearing rubber gloves shakes a gallon jug of water.
Photo: Tom Fenenga for Bob Vila

Step 5: Let sit for at least 30 minutes to allow the Epsom salt to completely dissolve.

Woman labels a gallon jug with a round sticker that says "plant food."
Photo: Tom Fenenga for Bob Vila

Label the container and store it in a cool dry spot where kids and pets can’t get to it.

Tips for Using Homemade Plant Food

Woman feeds a houseplant with a watering can, with a jug of plant food nearby.
Photo: Tom Fenenga for Bob Vila
  • There’s no need to dilute your homemade plant food. It’s ready to go!
  • Feed potted houseplants once every 3 to 5 weeks. During the dog days of winter, when plants grow more slowly, once every 5 weeks is sufficient. When plants show renewed growth in spring, increase feedings to once every 3 weeks.
  • Use the same amount of homemade liquid plant food as you would normally water indoor plants. For example, if you typically give your potted fern 1 cup of water, substitute one cup of homemade plant food, which will provide sufficient water and nutrients.
  • Pour homemade plant food around the base of the plant, rather than on its foliage. This is the best way for the roots to absorb all the nutrients.
  • You can use this homemade plant food as an all-purpose fertilizer in an outdoor flowerbed or garden. After regular watering, while the ground is still damp, pour 2 to 3 cups around the base of each plant once every 3 weeks during the growing season. Stop feeding outdoor plants in late fall, before they go dormant.