Using the Right Fertilizers

Fertilizing plants is an important part of caring for them. Be sure to choose the right one to suit the plants’ needs and use it according to the directions on the package. There are fertilizers available for most plants, indoors or outdoors.

When possible, it’s best to use organic and/or natural fertilizers. Synthetic fertilizers degrade soil health by killing beneficial microbes. They also may attribute to chemical run-offs that can cause aquatic dead zones. Synthetic fertilizer production also relies heavily on fossil fuels.

The Components

Each fertilizer is coded with three numbers, (for example: 5-10-5). The first number represents Nitrogen, the second is Phosphorus and the third is Potassium.

• Nitrogen (or N): Promotes leaf growth and dark green color. It’s most important for foliage house plants, leafy vegetables, evergreens, trees, and shrubs.
• Phosphorus (or P): Promotes root growth, sturdy stems, flowering, and fruiting. Most important for flowering plants, vegetables, flowering trees and shrubs, fruit trees, bulbs, and perennials.
• Potassium (or K): Balances the effects of nitrogen and phosphorus, and promotes root growth. Most important for root crops such as potatoes, turnips, etc.

Fertilizer Ratios for House Plants

It can be tricky to find the best kind for your plant’s needs. Here’s a handy guide for what fertilizers and ratios to look for, depending on the plant.

All Purpose Fertilizers: For flowering and foliage plants.

• 10-10-10
• 20-20-20
• 2-3-2

Continuous Feed Fertilizers: Slow release granules that feed the plant for 6 to 8 weeks.

• 3-1-2
• 14-14-14
• 10-10-10
• 9-3-6

Fertilizer for Acid Loving Plants: Water soluble that lowers soil pH and contains extra iron or sulfur. Great for plants such as Gardenias.

• 30-10-10
• 4-3-4

Fertilizer for Foliage Plants Only: Such as ferns. Diluted liquid fertilizer.

• 1-1-1
• 5-5-5
• 10-10-10
• 3-1-2

Fertilizer for African Violets: Water soluble, diluted liquid fertilizer.

• 14-12-14
• 8-14-9

Fertilizer for Orchids: Dependent on blooming, diluted liquid fertilizer.

• 20-20-20
• 10-10-10
• 30-10-10

Ratios of Fertilizer for Outdoor Plants

Get the most out of your garden with fertilizer best suited to the plant. Certain plants prefer certain types, so always check the tag your plant came with first for any specifications. Otherwise, the following ratios are generally preferred for the corresponding plant type.

Annuals:

• 15-30-15
• 20-20-20

Perennials:

• 10-10-10
• 3-4-5

Deciduous Trees & Shrubs: depends on prioritizing leafy growth or flowers

• 10-10-10
• 16-4-8
• 12-6-6

Evergreens:

• 12-4-8
• 10-8-15

Berries:

• 5-4-4
• 4-3-4

Fruit Trees:

• 10-10-10 for trees under 3 years old
• 6-2-4 once fruit producing

Vegetables:

• 10-5-5 for leafy vegetables
• 5-10-5 or 5-10-10 for fruiting vegetables

Natural Fertilizer Solutions

Some plants may be well suited with a natural solution, but it’s important to know what kind of nutrients it’s providing your plant with. Some plants are very sensitive to the types of nutrients they take in, so watch out for an “overdose” on your plant.

In general, the following items can make great natural solutions to your plants:

• Compost (click here to learn about making your own!)
• Banana Peels – adds potassium for flowers and fruit
• Coffee Grounds – good for acid-loving plants or to boost nitrogen

Learn more about natural garden fertilizers with the Farmer’s Almanac.

A Final Word

Before selecting a fertilizer, be sure to check the contents with the plant’s needs. Always use it according to directions.

If you’re looking for fertilizers, explore our Garden Supply Department. Ashcombe Farm & Greenhouses carries a variety of brands and types of fertilizer, providing you with exactly what your plant needs.