Feeding Your Plants 101: A Podcast

How can you tell if your plant needs fertilizer? What fertilizer should you use, and are you doing it correctly?

This podcast episode is a fun deep dive into some of the most asked questions about fertilizer. Click on the Play button below to listen!

Fertilizer FAQ’s

• Why is fertilizing important for tropical houseplants?

  Tropical houseplants need fertilizer because the nutrients in their potting soil get used up over time. In their natural environment, they get a constant supply of nutrients from decomposing organic matter, but indoors, we need to replenish these nutrients with fertilizer to keep them healthy and growing strong.

• What are the main types of fertilizers for tropical houseplants?

  You'll find several types of fertilizers:

  • Liquid Fertilizers: These are pre-mixed and easy to add to your watering routine.

  • Granular Fertilizers: Slow-release pellets or granules that provide nutrients gradually.

  • Organic Fertilizers: Made from natural sources like compost, offering a gentler, slow-release option.

  • Water-Soluble Fertilizers: Powdered fertilizers that quickly dissolve in water for easy application.

  • Controlled-Release Fertilizers: Coated pellets that provide a steady supply of nutrients over a longer period.

• What are the essential nutrients for tropical houseplants?

  The key nutrients are:

  • Nitrogen (N): Crucial for leaf and stem growth.

  • Phosphorus (P): Supports root development and flower production.

  • Potassium (K): Important for overall plant health and disease resistance.

  Look for an NPK ratio on the fertilizer label that indicates the percentage of each nutrient.

• How often should I fertilize my tropical houseplants?

  A general guideline is to fertilize every 2-4 weeks during the spring and summer growing season. Reduce the frequency to once a month in the fall and every 6-8 weeks during the winter dormancy period. Observe your plants and adjust based on their growth and needs.

• What is the best NPK ratio for tropical houseplants?

  A balanced fertilizer with an NPK ratio of 10-10-10 or 20-20-20 is a good starting point for most tropical houseplants. If your plant focuses on foliage, a fertilizer higher in nitrogen (like a 3-1-2 ratio) might be beneficial. For flowering plants, consider a fertilizer slightly higher in phosphorus to encourage blooms.

• What are some signs of over-fertilization?

  Watch out for:

  • Leaf burn: Brown or scorched leaf edges or tips.

  • Stunted growth: Slow or no growth despite proper watering and light.

  • Wilting: Drooping foliage even when the soil is moist.

  • Leaf yellowing: Yellowing that is accompanied by dark green foliage.

  If you notice these signs, flush the soil with plenty of water to remove excess fertilizer salts and stop fertilizing until the plant recovers.

• Can I use soil amendments to improve the soil for my tropical houseplants?

  Yes, soil amendments can greatly benefit your plants. Worm castings add nutrients and improve soil structure. Magnesium sulfate can enhance nutrient absorption, while incorporating compost provides a slow release of nutrients.

• What are some other important factors for healthy tropical houseplant growth?

  • Proper watering: Water thoroughly when the soil is mostly dry, but avoid overwatering.

  • Adequate light: Choose a location with bright, indirect light for most tropicals.

  • Optimal temperature and humidity: Maintain a comfortable temperature between 65°F to 85°F (18°C to 29°C) and moderate humidity.

  • Regular inspection: Check for pests, diseases, or signs of nutrient deficiencies.