7 Best Fertilizers for Houseplants
Updated: Apr. 10, 2023
Houseplants rely on you for the nutrients they need to remain healthy. Choose the best fertilizer for your houseplants and watch them grow and bloom.
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Do Houseplants Need Fertilizer?
There’s no question that houseplants, like any other flora, do better when they receive a regular diet of soil amendments (aka fertilizers).
Lisa Eldred Steinkopf, The Houseplant Guru, says feeding indoor-dwelling plants the proper nutrients keeps them healthier so they can fend off diseases and pests. And for flowering houseplants, fertilizer helps increase blooms.
“In their natural habitats, plants would be growing in soil that has nutriments from earthworms and other animals, rain, and decomposing organic material such as leaves,” Eldred Steinkopf says. Most houseplants live in “soilless” potting medium, making supplementing with fertilizers of utmost importance.
Eldred Steinkopf shares some houseplant fertilizer-related care tips and rules:
- More is NOT necessarily better: Â Adding more houseplant fertilizer than recommended on the label may do more harm than good. “It could ‘burn’ the roots and cause the collapse of your plant,” Eldred Steinkopf says.
- The once-a-month Plan: Fertilize plants every fourth watering, or every time you water at 1/8- to 1/4-strength.
- No grow. No fertilizer: Depending on available lighting, it may not be necessary to fertilize plants that aren’t actively growing. If light levels remain consistent throughout the year via indoor grow lights, then fertilize year-round.
- Be steady: “Don’t beat yourself up if you aren’t consistent with fertilizing your plants,” she says. “Your plants will be okay, but consistency is better.”
You may notice products called “plant food” and wonder if they’re better for your plants than fertilizer. Eldred Steinkopf says there’s no difference.
“It’s a marketing ploy to get people to think they are `feeding’ their plants plant `food,’ ” she says. “Plants make their own food through photosynthesis. It is more like vitamins to your plants.”
The following are some of the best fertilizers for houseplants.
Best All-Purpose Fertilizer for Houseplants
Eldred Steinkopf says she uses Jack’s Classic 20-20-20 All Purpose Fertilizer because it works. The water-soluble fertilizer features a balanced mix of nitrogen, phosphorous and potassium that’s especially effective on indoor foliage.
An Amazon five-star reviewer writes: “I use this at half strength for my seedlings and as directed for my houseplants when I think they need a boost. Everything is growing nicely and flowering.”
Best Organic Fertilizer for Houseplants
Sometimes you can’t beat Mother Nature.
Neptune’s Harvest Fish & Seaweed Fertilizer is an organic blend of hydrolyzed fresh-caught North Atlantic fish and seaweed. These ingredients have long been recognized for their ability to build natural sugars in plants, which in turn produces stronger greenery and more fragrant and colorful flowers.
Mix with water and apply Neptune’s with a watering can or sprayer. The briny elixir is made at the company’s docks in Gloucester, Massachusetts.
Best Synthetic Fertilizer for Houseplants
“Organic fertilizers need soil microbes to help break them down,” says Eldred Steinkopf. “This happens in soil. If your houseplants are growing in a soilless potting mix, synthetic fertilizers will work better.”
Dyna-Gro Liquid Grow Plant Food 7-9-5 is a super concentrated synthetic liquid fertilizer with six essential and 10 micro-nutrients that houseplants love. With a low soluble salt index, Dyna-Gro is less likely to injure/burn roots and can protect against diseases.
Best Fertilizer for Cacti and Succulents
Cacti and other succulents famously make houseplant care easy. Because they’re used to nutrient-deficient desert soil, they generally need less fertilizing than other houseplants.
Miracle-Gro Succulent Plant Food is specially formulated to give cacti, jade, aloe and other succulents the right level of nourishment. Squirt Miracle-Gro directly onto the soil with the pump bottle or mix it with water. It’s really that simple.
Best Slow-Release Fertilizer for Houseplants
Want to only apply houseplant fertilizer twice a year? All-in-one Osmocote Plus Outdoor & Indoor can supply continuous nourishment in potting soil for up to six months. The individual little granules, coated in a semi-permeable resin, dissolve gradually, releasing 11 essential plant nutrients over time.
Best Orchid Fertilizer
Affectionately called “magic” by the American Orchid Society, MSU Orchid Fertilizer 13-3-15 is taking the orchid world by storm.
Exotic and formidable, caring for orchids can be a balancing act. The tall stalks and tropical blooms need to be fertilized regularly, and not with just any old fertilizer. Developed by Michigan State University, the powdered orchid plant food can be mixed with rain, purified or tap water.
Best Hydroponic Houseplant Fertilizer
Special fertilizers are required for “soil-free” hydroponic gardening. AeroGarden Liquid Nutrients contains a pH buffering system that delivers nutrients dissolved in water directly into the roots.
The one-liter container can be purchased alone or with a 50-pack of reusable grow baskets and/or a mixed, pre-seeded pod kit (in six or nine counts) of non-GMO salad greens.
Originally Published: August 15, 2022
