Treatment Plans
Feed with a balanced fertilizer
Why do plants need a complete meal, just as we do?
Your plants need more than water and light. They need food too. Balanced fertilizer is like a complete meal, supplying the three essential nutrients they need for healthy growth. Without this support, the plant becomes depleted, much as we do after a long day without eating.
The key is three letters: N-P-K. N, nitrogen, is essential for green leaves and vigorous growth. P, phosphorus, helps build strong roots and produce flowers. K, potassium, strengthens the plant against disease and stress. A 10-10-10 or 20-20-20 fertilizer supplies these three elements in equal proportions. It is the ideal all-purpose formula for most houseplants.
Within a few weeks, you will see a difference: new leaves will be larger and more colorful, and overall growth will pick up again. It is the boost the plant needed to regain its vigor.
What to do now
- Choose an all-purpose or foliage houseplant liquid fertilizer with balanced NPK numbers, such as 10-10-10 or 20-20-20.
- Read the package directions carefully. If in doubt, use half the recommended dose. Too little is better than too much.
- Water your plant with plain water first. Applying fertilizer to dry potting mix can severely burn roots.
- Dilute the fertilizer in a watering can filled with water, following the stated proportions.
- Pour the mixture slowly over the whole surface of the potting mix until water starts flowing from the drainage holes.
- Apply every 2 to 4 weeks, only during active growth. The French reference gives March through September; use your local active growing season rather than fixed dates in other climates.
Prevention
- Fertilize regularly during the growing season, usually spring and summer in temperate climates.
- Stop or greatly reduce fertilizer during fall and winter where these bring slower growth.
- Check leaf color once a month for deficiency signs.
- Repot every 2 years in fresh mix naturally rich in nutrients.
Common problems
- Nitrogen deficiency · Older leaves turn uniformly yellow first.
FAQ
What do the N-P-K numbers on fertilizer mean?
N-P-K stands for the three main nutrients: **N** for nitrogen, **P** for phosphorus, and **K** for potassium. The numbers indicate the percentage of each nutrient in the fertilizer. For example, a **20-20-20** fertilizer contains 20% nitrogen, 20% phosphorus, and 20% potassium. Nitrogen supports foliage, phosphorus supports roots and flowers, and potassium supports overall plant health.
How do liquid and granular fertilizers differ?
**Liquid** fertilizer is mixed into irrigation water and acts very quickly because nutrients are immediately available to roots. **Granules** or sticks release nutrients slowly into the potting mix with each watering, feeding the plant over a longer period, generally several months. Liquid is ideal for a quick boost, while granules are convenient for ongoing maintenance.
What are the signs of too much fertilizer?
Overfertilizing is more dangerous than a deficiency. Signs include dry, **brown leaf tips**, yellowing leaf edges, stalled growth, and general wilting even when the mix is moist. You may also see a **whitish crust** of mineral salts on the potting mix.
Should I fertilize plants in winter?
Generally, no, where winter brings low light and a rest period. Most houseplants in those conditions stop actively growing and do not need extra nutrients. Continued fertilizer may even harm them by encouraging weak, stretched growth. The French reference calendar advises stopping from **October through late February**; elsewhere, follow the local low-light rest period rather than those dates.
Should I choose synthetic or organic fertilizer?
The nutrients are the same to the plant, so the choice depends on your preferences. **Synthetic**, or mineral, fertilizers provide precise doses and fast action. **Organic** fertilizers, made from guano, seaweed, and similar materials, release nutrients more slowly, reducing burn risk and improving soil microbial life over time.
Exactly how often should I fertilize?
During the growing season, usually spring and summer in temperate climates, the most common frequency for full-strength liquid fertilizer is **every 2 to 4 weeks**. Another excellent method is a very dilute dose, **1/4 of the recommended amount**, at every watering. This supplies nutrients steadily, which is more natural for the plant.
Should I fertilize a recently repotted plant?
No. Wait at least **4 to 6 weeks** after repotting. Fresh potting mix already contains the nutrients needed for the first few weeks. Fertilizing too soon could burn fragile roots adapting to their new environment.