What Fertilizer to Mix With Epsom Salts to Increase Flower Bloom?

Does This Plant Need It?

• Sometimes you can tell by looking at a plant that it will benefit from Epsom salt. If the plant's leaves are turning yellow all over or in between the leaf veins, sulfate and magnesium can help plants to produce chlorophyll and solve the problem. Even plants that already appear healthy can benefit from an application of Epsom salts. Magnesium sulfate encourages healthy growth and more prolific flowers in plants such as annual bedding plants and roses (Rosa spp., which grow in U.S. Department of Agriculture plant hardiness zones 2 through 11, depending on cultivar).

How Much to Use?

• To treat a specific plant problem, mix 1 tablespoon Epsom salts with a gallon of water and spray onto plant leaves every two weeks. You can also add Epsom salts to the soil. For roses, add 1 tablespoon Epsom salts when planting a new rose bush, or work 1/2 cup into the soil at the base of an established plant when new growth starts in the spring. When starting a new flower garden, mix 1 cup Epsom salts into the soil for every 100 square feet.

Bloom-Boosting Basics

• For plants to receive a balanced diet, Epsom salt must be mixed with another fertilizer containing nitrogen, phosphorous and potassium. Choosing a fertilizer with a high proportion of phosphorous will encourage plants to set more blooms. A typical water-soluble fertilizer can be mixed by adding 1 tablespoon to 1 gallon of water. Up to 1 tablespoon of Epsom salt can be added to this fertilizer mix. Each gallon of diluted fertilizer will cover 10 square feet of garden plants, and can be applied every seven to 14 days.

Organic Additives

• Epsom salts can also be used along with organic soil additives and fertilizers. To amend 100 square feet of average garden soil, add nitrogen by applying 2.25 pounds of blood meal, 12.6 pounds alfalfa meal, or 3 pounds of fish meal. Add phosphorous by applying 2 pounds bone meal or 4 pounds phosphate rock. Supplement potassium by applying 4.5 pounds crushed granite, 4 pounds of kelp meal, or 4 pounds of green sand. Mix in 1 cup Epsom salts for every 100 square feet.