Fertilizer Calculator

Yes, and it happens more often than you'd think. Too much fertilizer leads to salt buildup in the soil, which burns the roots. Typical signs: brown leaf edges, white crust on the soil, sudden wilting. When in doubt: fertilize a little less rather than too much.

Liquid fertilizer is more flexible — you can adjust the dose precisely and pause when needed. Fertilizer sticks are convenient for beginners but release nutrients continuously — even during dormancy, when the plant doesn't need them. For most plants, liquid fertilizer is the better choice.

Most houseplants go through a natural dormant period in winter. During this time they need little to no fertilizer. Exception: plants that bloom in winter (e.g. Christmas cactus, amaryllis) or grow actively year-round under grow lights.

N = Nitrogen (for leaf growth), P = Phosphorus (for roots and blooms), K = Potassium (for overall plant health). Foliage plants need more N, flowering plants need more P. A balanced fertilizer might be NPK 7-7-7, for example.

Organic fertilizers (e.g. compost tea, worm castings) improve soil structure long-term and release nutrients slowly — though they can smell and act more slowly. Mineral fertilizer works fast and is odorless but can damage roots if overdosed. For most hobby gardeners, a quality organic-mineral liquid fertilizer is the best mix.