How to fertilize house plants: type, amount and timing
Potting mix runs out of food in a few months. A little fertilizer in spring and summer keeps leaves green. Too much fertilizer harms roots, so use less than the label says.
This is general care advice. Check the label of your plant. Keep toxic plants away from pets and children.
What you need
- A balanced liquid houseplant fertilizer (for example NPK 3-1-2 or 10-10-10)
- Or slow-release granules, or an organic fertilizer
- A measuring spoon or cup
- Water
Steps
- Choose a fertilizer. A balanced liquid houseplant fertilizer is easy to use. Slow-release granules and organic fertilizers also work.
- Read the label. Use half of the label strength. This is safe for most house plants. Houseplants grow slower than garden plants.
- Feed only in the growing season, in spring and summer. Feed every 2 to 4 weeks, as the plant care page says.
- Feed less or not at all in autumn and winter. Plants grow little then and cannot use the food.
- Test the soil with a finger first. Water the plant if the soil is dry. Wait until the soil is moist. Then feed.
- Mix the fertilizer with water as the label says, at half strength. Pour it slowly on the soil. Keep it off the leaves.
- Once every 2 to 3 months, flush the soil with plain water. Pour water through the pot until it runs out of the holes. This removes extra salts.
Check your plant
Answer the questions. The guide shows what to do.
Warnings
- Never feed dry soil. It can burn roots.
- Do not feed a sick plant, or a plant you repotted in the last 4 to 6 weeks.
- Too much fertilizer shows as white crust on soil or pot rim, brown tips and edges, or wilting in moist soil.
- Cacti and succulents need very little fertilizer.
Questions and answers
How often should I fertilize house plants?
Feed every 2 to 4 weeks in spring and summer, as the plant needs. Feed less or not at all in autumn and winter.
What fertilizer is best for house plants?
A balanced liquid houseplant fertilizer, for example NPK 3-1-2 or 10-10-10, at half strength works for most plants.
How do I fix too much fertilizer?
Flush the soil with lots of water. Remove the white crust. Do not feed for a month.