When to Fertilize Roses: Your Guide to Rose Fertilization Timing and Techniques

When to Fertilize Roses: Your Guide to Rose Fertilization Timing and Techniques

Roses are some of the most beautiful flowers you can grow in your garden. From their stunning colors to their different types and styles, you can grow a rose that climbs a trellis at the back of your garden or fills out the center of a perennial bed in your yard. You can grow roses that are red and white, or lipstick pink, or bright orange, and you can also grow roses that are delicate shades of purple, butter yellow or soft white. With so many options to choose from, it’s no wonder that roses are so popular across the country. 

But some gardeners hesitate to add roses to their garden because they feel a little challenging. While they aren’t the most high-maintenance plant out there, they do need regular care to ensure they’re blooming at their best for years to come. That being said, once you know what to do, they’re as easy as any other flower to keep happy and healthy. We’ve put together a guide to explain how to fertilize your roses and ensure they grow all season long year after year.

To Fertilize or Not to Fertilize

Roses love to eat. They crave nutrients from the soil in order to continue to bloom all season long and fight off various diseases. While most roses can go without being fertilized, the majority of roses prefer to have a consistent source of fertilizer throughout the growing season. The easiest way to know if your rose should be fertilized is to check to see how many times it blooms. If it’s a repeat bloomer like a hybrid tea rose or a floribunda variety, you’ll want to fertilize several times throughout spring, summer and fall. 

What to Know About Fertilizer

There are three important ingredients in all fertilizers: nitrogen, phosphorus and potassium. If you look at fertilizer packaging, this is sometimes shown as the N-P-K ratio. Each ingredient has a purpose in every bag or spray of fertilizer:

the N-P-K ratio
  • Nitrogen—helps the plant continue to create new growth throughout the season.
  • Phosphorus—supports root growth, which is especially important when first planting a rose.
  • Potassium—keeps the entire rose healthy when it’s stressed by heat, drought or insect and disease attacks. 

In addition to normal fertilizer ingredients, roses enjoy their own special blend of nutrients akin to a multivitamin we might take. These nutrients include calcium for plant strength and magnesium for vibrant leaves and flowers, as well as things like sulfur, zinc, iron and more. These extra nutrients are typically why you may see regular fertilizer and rose fertilizer at your favorite nursery. Roses need just a little more for them to grow their best.

Shop Show-Stopping Hybrid Tea Roses

How to Pick a Fertilizer

There are plenty of fertilizers on the market, so how do you know which one is going to be right for your roses? The first thing to ask yourself is if you want organic or inorganic fertilizer. Many gardeners strive for a healthy, organic garden that’s free of man-made pesticides, so choosing an organic fertilizer might be your preference. Once you’ve decided the type of fertilizer to get, it’s time to start looking at your options. 

fertilizer options
  • Consider Compost—Compost cannot be created overnight, so if you need something immediately, you’d have to buy your own compost rather than make it. But you can make compost yourself using leftover cuttings from the garden, raked leaves, grass clippings, old vegetables and fruits and a little bit of soil. Pile them in a corner of your garden or in a compost bin and let nature do the work for you. You’ll need to flip your compost a couple of times, but by next season, you should have usable compost for your entire garden.
  • Try Other Organic Fertilizers—In addition to compost, you can use things like manure, fish fertilizer, bone meal, alfalfa and other plant- and animal-based products to push nutrients back into the soil. While organic fertilizer may be better for the environment and your garden, it tends to not be quite as nutrient-packed as synthetic fertilizers, which means you’ll need to fertilize your roses more often with it. Using a liquid organic fertilizer may cut down the number of times you’ll need to fertilize if you prefer organic options.
  • Consider Inorganic Fertilizer—Inorganic fertilizer can make fertilizing throughout the growing season easier. There are plenty of options that aren’t as expensive as organic fertilizers, and they work for a longer period of time. Plus, they come in a variety of forms, like liquid, slow-release capsules and granular. It’s important to note, however, that inorganic fertilizer can pack a serious nutrient punch, and this can negatively affect roses with root burn. Root burn is literally what it sounds like — the soil becomes too enriched and actually hurts the plant. When choosing an inorganic fertilizer, we recommend a rose fertilizer you only use once that slowly releases nutrients over time. 

Best Times to Fertilize

fertilizing soil of rose bushes

There are a few things to know before deciding when to fertilize. For example, are you planting your roses in an area that has healthy, nutrient-rich soil? Or are you planting your rose in a spot where something else died off? Knowing these things can help you decide whether you need to fertilize and help you plan out when to fertilize.

Fertilizing During the First Year With Good Soil

Generally speaking, you can tell a good spot of soil in your garden. You put your shovel in and the soil is rich and dark, filled with earthworms, and fairly easy to dig in. This sort of soil may not even require fertilizing in the first year of planting. However, if you want to give your rose an extra boost, we recommend mixing the soil with a bit of compost or a single dose of organic or inorganic fertilizer. Then, plant your rose, water it and stick to a regular watering schedule for the first year. 

Fertilizing During the First Year With Poor Soil

Whether something was planted in your new rose’s spot, or it’s just not a great place for soil in your yard, you’ll want to amend your soil before planting your rose. First off, you may want to test your soil. This will let you know if the soil is acidic or alkaline, and you can adjust accordingly. Roses prefer soils with a pH between 6 and 6.5. 

Once you’ve amended your soil, don’t be afraid to add garden soil or topsoil, along with compost, into your existing soil. This will give your roses the best start. Then, add a single dose of fertilizer and plant your rose. Fill the hole around the rose’s roots with more of the nutrient-rich soil to give it a good foundation. Water it and let your rose grow. 

Once you see several inches of growth on your rose, add a bit more fertilizer and continue to add fertilizer every five to six weeks or per your fertilizer’s instructions. Some rose fertilizer only requires one application a year. 

Fertilizing After The First Year

After the first year of growth, you’ll want to start your fertilizing process as soon as you’re able to start working the soil. You’ll keep fertilizing throughout the season unless you’re using a slow-release granular fertilizer. 

As you near the end of the season, most northern gardeners stop fertilizing about eight weeks before you might experience a frost. This doesn’t have to be exact, but it is a good way to allow the rose to prepare for winter and reduce any potential frost damage that would stress the plant out before going dormant. 

If you live in a zone that typically doesn’t see frost, your rose will still probably go dormant for a couple of months, so stop fertilizing about eight weeks before typical dormancy times. This is likely closer to October or even November. 

The most important thing to do is purchase a high-quality rose fertilizer and then read the instructions on the packaging. This will give your rose the best chances at getting the nutrients it needs without giving it too much of a good thing. It also makes it easier if you’re not an experienced rose gardener to keep your roses blooming and beautiful. 

Add Your Favorite Roses To The Garden

fertilizing rose bush soil

Signs That It’s Time to Fertilize

Your roses may not be able to talk, but they can still tell you things if you’re paying attention. From the color of the leaves to the brightness of the blooms, a rose that’s lacking nutrients can be pretty obvious when you know what to look for. Here are some common problems new rose gardeners face with their roses: 

  1. Blooms Are Small and Pale—If your rose is presenting you with lackluster flowers, chances are it doesn’t have enough nitrogen in the soil. Add more to perk those blooms up. 
  2. Leaves Don’t Shine—Rose leaves tend to be bright and even glossy, so if your rose’s leaves look drab, there’s a good chance they need more phosphorus. 
  3. Leaves Have Yello Edges—While this can be a sign of disease, typically, yellow edges which turn brown after a little while often means your rose is lacking potassium. 
  4. Plant Won’t Grow—Nitrogen is a building block for your rose’s cells, so if it’s staying small, it might be time to add more nitrogen to your soil. 
  5. Buds Don’t Open—If your rose is producing buds, but they’re not opening, it’s probably a sign that your rose doesn’t have enough phosphorus. 
  6. Plant Has Weak Stems—Stems are important because they hold the rose blossom up for pollinators (and for gardeners) to enjoy. Weak stems tend to be an indicator of a lack of phosphorus and/or potassium. 
  7. Plant Is Big But Has No Flowers—You might think that a problem facing your rose means it’s not getting enough of something. However, if you have a giant rose with no blooms, it’s likely getting too much nitrogen. You can fix this by amending it with soil from elsewhere in your garden to cut down on the nitrogen content in that area.

Staying on top of your soil, fertilizing according to the package’s instructions and using a high-quality rose fertilizer can make avoiding these challenges easy, but sometimes you’ll face others when it comes to roses. So how do you know if it’s pests or improper fertilization?

Is It Bugs or Soil Problems?

While you love your roses, unfortunately, some bugs do, too. Knowing the signs of bugs on your roses can make it easy to get rid of those pesky invaders and keep your roses happy and healthy. Remember, keeping your soil healthy can help your roses fight against the stress bugs cause, so you’ll need to both fertilize and keep on top of pests.

bug problems
  • Papery, Skeleton-like Leaf—This is typically a sign of sawfly larvae or rose slugs. These little worms love to start at the center of a rose’s leaf and work outwards toward the edge.
  • Curled, Yellow Leaves, Black Mold, And A Sticky Substance—Aphids are little green bugs that tend to be in almost every garden around the world. They like to eat the nutrients from your plants, but in the process, they’ll leave behind a little sticky substance that can lead to mold. 
  • Brown-streaked Buds and Silver-streaked Leaves—Rose thrips are tiny, yellowish-brown bugs that like to feed on rose leaves and flower buds. 

The good news about a lot of the pests that love roses is that they’re easy to kill. Simply fill a spray bottle with water and add some dish soap. The dish soap will sink into the skin of these bugs and kill them. There are also plenty of other insects and birds that eat these little menaces, so be sure to use pesticides that are safe for other critters in your garden to ingest. This way, you’re helping your roses and your garden’s ecosystem.

Taking care of roses by fertilizing at the right times with the right fertilizer can make all the difference in ensuring your roses grow big and beautiful.


Image Credits
OoddySmile Studio/Shutterstock.com
Anna Hoychuk/Shutterstock.com
Anna Jastrzebska/Shutterstock.com
Jurga Jot/Shutterstock.com