How and When to Fertilize Roses for Vibrant, Beautiful Blooms

You should begin feeding the perennial flowering bush in early spring.

Roses need regular fertilizing to grow strong, resist disease, and produce vibrant, beautiful blooms throughout the season.
Fertilize roses in early spring when new growth appears and stop feeding in late summer to prepare for dormancy.
Use a balanced fertilizer, like a 10-10-10 formula, and water thoroughly to help nutrients reach the roots.

Roses are a beloved flower. They're fragrant, and they look beautiful in a garden—or in a Valentine's Day bouquet. However, despite their incredible popularity, roses aren't the easiest bloom to grow.

These delicate blossoms are heavy feeders, so they'll need a lot of nutrients and must be regularly fertilized. The latter is especially important because fertilizing not only promotes healthy growth but also helps keep diseases at bay. Since roses are so picky, though, it's important to know exactly what they need before you start fertilizing. Here, we spoke to gardening experts to get the full scoop.

Wes Harvell, rosarian at Jackson & Perkins, a full-service nursery considered the world's foremost producer and marketer of roses.
Jimmy Speas, president of the Winston-Salem Rose Society, a society that was founded in 1953 and provides rosarians with the best practices for selecting, caring, and exhibiting roses.

When to Fertilize Roses

Fertilize roses in early spring as they begin to leaf out, waiting until you see about 6 inches of new growth. Continue to fertilize your roses during the growing season, stopping feeding in late summer or early fall when they begin preparing for winter dormancy. "Fertilizing late in the season may encourage unnecessary tender new growth which may get damaged by cold snaps in the fall," says Jimmy Speas, president of the Winston-Salem Rose Society. "This damaged growth may then be susceptible to further damage by pests."

Nutrients That Roses Need

Roses require several key nutrients, including nitrogen, phosphorus, and potassium. Additionally, they require trace elements such as calcium, magnesium, and iron, among others, says Wes Harvell, rosarian at Jackson & Perkins. "Without these nutrients, roses may have stunted growth, pale or discolored leaves, and decreased flowering," he says.

Nitrogen: Promotes healthy leaf and stem growth, giving roses a lush and green appearance.
Phosphorous: Supports the root development and flower and seed production of roses.
Potassium: Potassium enhances disease resistance, which improves flower quality and increases plant hardiness.
Calcium: Strengthens strong cell walls and chlorophyll production.
Magnesium: Like calcium, magnesium also strengthens strong cell walls and chlorophyll production.
Iron: Helps with photosynthesis and overall plant vitality.

How to Fertilize Roses

How you fertilize roses depends on the type you are growing and when they were planted. When applying the fertilizer, follow the instructions on the packaging for guidance on how much to use.

Newly Planted Roses

Wait at least six weeks after planting new roses before fertilizing them to allow time for the roots to establish, says Harvell. Sprinkle a balanced fertilizer specially formulated for roses, such as a 10-10-10. around the base of the plant. After applying, water the plants thoroughly to help the nutrients reach the roots.

Established Roses

Fertilize established roses in early spring as new growth begins and again in late spring or early summer after the first flush of blooms, says Harvell. Scatter a balanced fertilizer specially formulated for roses, such as a 10-10-10, evenly around the drip line (the area under the outermost branches) of the rose bush, says Harvell. Water the plant thoroughly after fertilizing.

Container Roses

Fertilize container roses every four to six weeks during the growing season. "Use a water-soluble fertilizer or a slow-release granular fertilizer formulated for container plants," says Harvell. "Dilute the water-soluble fertilizer according to the instructions on the packaging and water the roses with it. If using a granular fertilizer, sprinkle it on the soil surface and lightly scratch it into the top layer of soil." Water the plant thoroughly after fertilizing.

Best Fertilizer for Roses

A balanced fertilizer specially formulated for roses is ideal, but you should have your soil tested before choosing a product. While a 10-10-10 ratio of nitrogen, phosphorus, and potassium (NPK) is recommended, a soil test will let you know if your soil needs more or less of a required nutrient.

Once you know the appropriate NPK ratio needed for your soil, you can choose a rose fertilizer. The two most common types of fertilizer are liquid fertilizer and slow-release granular fertilizer. Liquid fertilizer is often used in the first year as it is less likely to burn new roots, says Speas. This type of fertilizer is typically applied more often than slow-release.

Organic vs. Non-Organic Fertilizer

Both liquid and granular fertilizers come in organic and non-organic formulas. "Organic fertilizer is from naturally derived sources such as manure, fish emulsion, bone meal, or compost," Smith says. "Inorganic fertilizer is man-made from synthetic chemicals."

Although each one contains the necessary nutrients that roses need to bloom, Speas is a fan of organic options. "Organics feed microorganisms that enable the roses to use the nutrients in the soil for food," he says. This, in turn, enhances the bloom color and reduces the risk of root and leaf burn.

Frequently Asked Questions

Is 10-10-10 good for roses?

Yes, 10-10-10 is generally recommended for fertilizing roses; though a soil test will determine if it's the right ratio for your garden.
What does Epsom salt do for roses?

Epsom salts are a chemical compound consisting of magnesium, sulfur, and oxygen. "Magnesium is an essential nutrient for plants. It plays a crucial role in chlorophyll production, which is responsible for the green color in leaves," says Harvell. "Epsom salts can help prevent magnesium deficiency in roses, resulting in healthier foliage."
Do roses like coffee grounds as fertilizer?

Coffee grounds contain the essential nutrients roses need, including nitrogen, phosphorus, and potassium. "They can help to improve soil structure and attract worms, benefitting your rose plants," says Harvell. "However, it is essential not to overdo it, as too much coffee grounds can make the soil too acidic and disrupt the pH balance."
What happens if you don’t fertilize your roses?

Your roses might not reach their full potential in terms of growth and bloom production if they aren't fertilized.