There are a lot of different kinds of fertilizers available for roses.
Choosing the right one is not always easy but it is so important to get the strongest plants and most beautiful blooms.
Here’s what you need to know to choose the best fertilizer for roses.
Table of Contents
What Does Fertilizer Do for Roses?
All fertilizers include three main nutrients and each has a particular role to play in plant growth. They are:
- Nitrogen (N). Nitrogen is an essential part of plant proteins and helps promote dense, leafy growth. It is essential to just about every process occurring inside the plant, including photosynthesis, new leaf growth, and protection against pests.
- Phosphorus (P). This nutrient is involved in plant metabolism and necessary for energy transfer. In addition to getting energy from the stem to the tips of the leaves, phosphorous is also needed for root and flower development, making it especially important for roses.
- Potassium (K). The main purpose of potassium is to help plants tolerate stress. It helps regulate water pressure in and around individual plant cells and it important for strong root development.
An easy way to look at it is nitrogen is for the plant, phosphorus is for the roots, and potassium is for the whole plant. When buying any kind of fertilizer, the nitrogen to phosphorus to potassium (NPK) ratio should be indicated on the side of the package.
The fertilizer needs of roses vary throughout the year. They need a much different NPK ration in the spring than they do toward fall when they’re nearing the end of their blooming season.
Finding the right balance throughout the growing season makes roses strong and improves the quality of the blooms.
There are rose varieties that can grow in just about any of the planting zones in the United States which are classified based on the average low temperature. Dormancy and length of blooming season vary depending on the zone but preparation for blooming should start in the spring regardless of zone.
High-nitrogen fertilizer is recommended for spring. Follow the directions on the packaging but, generally, about ⅓ cup per plant is good. Apply to the soil at the base of the plant and water it in. For new plants, the best time to add fertilizer is after you see about six inches of growth.
As we mentioned, nitrogen is essential for plant growth and just about every function inside the plant. That’s why it is so important to load up the soil with it in the spring. For best results, do an application of high-nitrogen fertilizer monthly for two months in a row, usually in March and April.
Try this: Miracle-Gro Water Soluble All Purpose Plant Food has an NPK ratio of 24-8-16 which gives your roses the nitrogen they need to prepare for summer blooms while also adding some strength to the rest of the plant.
As spring turns to summer, roses fertilizer requirements change. In spring, they’re gearing up for rapid growth and need a lot of nitrogen. In summer, they’re getting ready to bloom and require a more balanced routine.
The best type of fertilizer for roses in the summertime has an even NPK ratio. This supports growth, strength, and overall plant health. Use about ½ cup for every four feet of height per plant. Apply to the base and water in thoroughly. For best results, do this once a month starting in May until August.
Try this: All Season’s Plant Food can be used on roses as well as vegetables, trees, and your lawn. This makes it easy to fertilize everything at once while making sure your roses get everything they need for big, beautiful blooms.
Late Summer/Early Fall
When summer comes to an end, the needs of your roses change once again. In most climates, they’re heading toward their dormant period so they don’t need new growth.
The strategy for fertilizing is essentially the opposite of what it was in spring. That is, you should use fertilizer without nitrogen. If fertilizer with nitrogen is used, it could prevent the plant from going dormant which could make it more vulnerable to the inevitable cold weather.
An NPK ratio of with little to no nitrogen is ideal. The phosphorus and potassium will help the roots grow strong for next year and prepare the plant for the cold winter.
Water-soluble fertilizer is best because it can easily travel through the soil to the roots. Do one application on September and one in October and then you’re done until March when it’s time to get ready for spring again.
Try this: Hawaiin Bud and Bloom has an NPK ratio of 5-50-17. The high phosphorous content will help roots stay strong over the winter and provides the potassium needed for general plant health.
Other Things to Consider
The type of fertilizer that’s best for roses also has to do with the type of soil. Roses grow best in slightly acidic soil which can influence how effective any fertilizer is. If you have tried different fertilizers and are finding that nothing is really working, having the soil tested is the next step.
Another decision you have to make is whether you want to use an organic or chemical fertilizer. There are good and bad things about both.
Organic fertilizers are usually good at feeding both the plant and the soil but may need additional applications. Chemical fertilizers don’t always have long term effects on the soil but are often able to prevent damage from insects, fungus, and other plant diseases.
Rotating chemical fertilizers is a good idea, not only because it tailors the nutrients to the time of year but also because there’s less chance of chemical buildup. Over time, this could have long term effects on the soil.
Organic fertilizers do not usually cause this kind of buildup because they’re just not as strong as chemical ones. Using a blend of chemical and organic fertilizers is a good approach because you get all the benefits of each without as many negatives.
What Fertilizer to Use for Roses, Homeguides.Sfgate