When to Fertilize Roses: Type, Zone, Month, With Handy Chart

I’ve written a lot of articles about fertilizing roses, the various types, and how to use them. But when to fertilize roses can depend on a few factors, so I’m going through those in this article.

For most growing zones in the northern hemisphere, you should fertilize roses from April to September. When to start, how often, and what type of fertilizer depends largely on your particular zone (or month), the type of fertilizer, and how much to add.

Let’s go through the factors in quick detail so you can figure out when to fertilize roses in your garden.

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When to fertilize roses based on the type of fertilizer

The first factor is what type of fertilizer you’re using. If you’re using chemical fertilizer, then you’ll want to fertilize more often than if you’re using an organic fertilizer. This is because chemical fertilizers release their nutrients more quickly and so they need to be applied more often.

When to add fertilizer to roses based on the time of year

The second factor is what time of year it is. roses grow more actively in the spring and summer, so they’ll need more fertilizer during those times. In the fall and winter (and just prior to these seasons), when growth slows down, you can reduce the amount of fertilizer you’re using.

When to fertilize roses based on your growing zone

The third factor is which growing zone you live in. If you live in a warmer climate, then you can fertilize your roses year-round. But if you live in a colder climate, then you’ll want to stop fertilizing in late summer or early fall so that the plants can go into dormancy for the winter.

So, when should you fertilize your roses? The answer depends on all of these factors. A good general rule of thumb is to fertilize every 4-6 weeks during the growing season, and then reduce or stop altogether when growth slows down in the fall and winter.

Check the fertilizer instructions

But be sure to check the instructions on your fertilizer for specific guidance, as different products may have different recommendations.

Let’s go through some nuances on when to fertilize roses.

When to fertilize roses – Initial fertilizing and frequency

Roses can use a boost at the time when they are starting to wake up from their winter slumber. So look to first add fertilizer when new growth appears in spring. You can either:

1. Side-dress: (apply the fertilizer next to the plant, being careful not to get it on the leaves) or
2. Top-dress: (scatter it on top of the soil around the plant).

Then, throughout the growing season, continue to fertilize every 4-6 weeks. The best time to do this is after you’ve deadheaded the roses.

In general, If you live in a warm climate, you may be able to get away with fertilizing once a month. But in general, it’s best not to overdo it.

Again, different types of fertilizer will have varying recommendations, so be sure to read the instructions on your fertilizer for specific guidance.

Frequency of adding fertilizer to roses

As I’ve eluded to above and which is very important, is that the frequency with which you need to fertilize your roses will largely depend on the type of fertilizer you use.

If you’re using a slow-release fertilizer, you’ll need to apply it less often than if you’re using a liquid fertilizer. Slow-release fertilizers can last for several months, while liquid fertilizers will need to be applied every few weeks.

• Slow-release fertilizers are good for organic gardens and rose bushes that are already established. If you’re using a slow-release fertilizer, you should apply it in early spring and then again in mid to late summer.
• Liquid fertilizers are good for newly planted rose bushes or if you want to encourage lots of growth. If you’re using a liquid fertilizer, you should apply it every two weeks during the growing season.

Avoid fertilizing in late summer

In general, it’s best to avoid fertilizing in late summer or early fall. This can cause new growth that won’t have time to harden off and it won’t help to keep the rose blooming.

Here’s an infographic I’ve created that highlights the intensity of fertilizing through the year in the northern hemisphere. You’ll need to adjust this of course for the southern hemisphere.

Type of fertilizer

The type of fertilizer you use will also depend on the time of year. For example, you’ll want to use a different fertilizer in the spring than you would in the fall.

In the spring, you’ll want to use a fertilizer that’s high in nitrogen to encourage growth. In the fall, you’ll want to use a fertilizer that’s high in phosphorus to encourage root growth.

Can you add too much fertilizer to roses?

How much to add will depend on the particular fertilizer you have and that’s why you should follow instructions as carefully as possible. If you add too much fertilizer, it can actually harm your roses. Symptoms of over-fertilization include:

• Yellow leaves with green veins
• Spindly growth
• Brown or black patches on leaves
• Stunted growth
• Wilting leaves
• Unusually large thorns

How to correct adding too much fertilizer

If you see any of these symptoms, stop fertilizing and try flushing the soil with plenty of water to dilute the fertilizer. If the damage is severe, you may need to replant your roses.

Roses that may look like they can’t be saved can actually be recovered, as I’ve done with these miniature roses.

Some specific areas and when to fertilize roses

Now I’ll run through a few sample areas, states, and regions to give you some indication of when to fertilize roses around those areas. You can always consult the official USDA zone map to get a more detailed view.

When to fertilize roses in California

California is in growing zone 8 and 9. Fertilize roses in California once a month from February to September.

When to fertilize roses in Ohio

Ohio is in growing zone 6. Fertilize roses in Ohio every two weeks from April to September.

When to fertilize roses in New York

New York is in growing zone 6. Fertilize roses in New York every two weeks from April to September.

When to fertilize roses in Florida

Florida is in growing zone 9. Fertilize roses in Florida once a month from February to September.

When to fertilize roses in Texas

Texas is in growing zone 8. Fertilize roses in Texas every two weeks from March to September.

When to fertilize roses in Arizona

Arizona is in growing zone 9. Fertilize roses in Arizona once a month from February to September.

When to fertilize roses in Colorado

Colorado is in growing zone 5. Fertilize roses in Colorado every two weeks from May to September.

When to fertilize roses in the United Kingdom

The UK is in growing zone 8, with some areas being zone 7 or 9. Fertilize roses in the UK every two weeks from March to September.

When to fertilize roses in Ireland

Ireland is in growing zone 9 with some inner areas being zone 8. So fertilize roses in Ireland once a month from February to September.

When to fertilize roses in Australia

Australia is in growing zone 7 through 10. Fertilize roses in Australia every two weeks from September to March.

When to fertilize roses in New Zealand

New Zealand is considered to be in growing zone 8 through 10. Fertilize roses in New Zealand every week from November to February.

When to fertilize roses in South Africa

South Africa is in growing zone 9. Fertilize roses in South Africa every two weeks from September to April.

When to fertilize roses country or state round up table

State, Country, or Region	When to fertilize Roses
California	once a month from February to September
Ohio	every two weeks from April to September.
New York	every two weeks from April to September
Florida	once a month from February to September
Texas	every two weeks from March to September
Arizona	once a month from February to September
Colorado	every two weeks from May to September
United Kingdom	every two weeks from March to September
Ireland	once a month from February to September
Australia	every two weeks from September to March
New Zealand	every week from November to February
South Africa	every two weeks from September to April

Types of fertilizer for roses

There are many different types of fertilizers that can be used on roses. Much of it depends on what components the fertilizer brings to the soil and the plant. The best type of fertilizer to use for roses is a 10-10-10 or 20-20-20 fertilizer. This type of fertilizer is a complete fertilizer and will provide your rose bush with everything it needs to grow healthy and strong.

I’ve written an entire article on the best NPK ratio for roses that I’d recommend reading.

There are of course natural fertilizers and other treatments such as different types of manure. Here’s a list of natural fertilizers I’ve written about.

• Horse manure
• Chicken manure
• Cow Manure
• Human Urine
• Mushroom Compost
• Wood Ash
• Epsom Salt
• Bone Meal
• Eggshell
• Lime

When to fertilize roses ~ More roses help 🌹

As you can see, when to fertilize roses generally depends on a number of factors, and in truth, results can differ because of all the variables, even down to soil type, differing NPK rations, type of roses, etc.

So ultimately it’s down to what works best for you. I’d recommend trying a variety of natural and chemical fertilizers (I prefer natural fertilizers) and seeing which works on your roses.