Want your climbing roses to keep blooming their hearts out all summer long? The secret is in the feeding!
There’s nothing quite like the elegance of a climbing rose. Whether they’re elegantly winding up an arbor, charmingly trailing along a fence, or completely taking over a trellis, there’s nothing quite like their beauty.
But here’s the million-dollar question: how do you keep those blooms coming back and lasting as long as possible? Sure, the foliage is nice, but it’s those vibrant blooms that steal the show!
Climbing roses are massive bloomers, and they can keep going through the summer months, but they’re very hungry plants! If you want an insane flowering season from your climbers and ramblers, you need to start soon. Fertilize them in spring, and then again, to give them the energy to be the undisputed queens of your trellises, pergolas, and yes – your whole garden!
So, the secret to getting your climbing roses to blossom profusely for months is feeding them, but you need to know when, how, and with what. Choosing the right fertilizer can make a huge difference, and this is what we are going to learn.
When to Fertilize Climbing Roses
If you want your climbing roses to flower massively in late spring and summer, you must start very early indeed. As soon as you prune them, it is time to feed them as well, so, as we gardeners say, “when forsythia is in bloom”, or as soon as frost is behind us.
Early spring is the ideal time to fertilize climbing roses, and about four weeks before the first leaves open. And if you are late, hurry up!
You will also need to fertilize your climbing roses again after each flowering wave. At that stage, they need extra energy to boost their big blooms, so, keep an eye on them!
How Much Should You Feed Your Climbing Roses?
The answer is plenty! With climbing roses, it’s far better to err by excess than defect. The exact quantity depends on the size of your climber or rambler, and they can be massive! Many varieties easily hit 20 feet in height, or 6 meters, but the tallest of them all is a whopping 91 feet tall, or 27.7 meters, and it’s in Los Angeles, California.
However, I will give you the instructions for a medium sized one, between 12 and 17 feet tall (3.6 to 4.5 meters). And then you can adapt it if it is a small variety or a big one. And now, on to the ideal fertilizer mix for your climbing roses.
The Best Fertilizer Mix for Climbing Roses: Manure, Rose Food and Epsom Salt
This is by far the best fertilizer to give to your climbing roses, especially in spring. In fact, it will give it lots of long-lasting food with well-rotted manure, balanced with rose food, and then a boost for flowers with Epsom salt.
But be very careful, I said “well-rotted manure”, which means that it must be at least two years old. If you feed them fresh manure, it risks burning the canes of your climbing roses, it can cause molds and fungi, and it will give them too much nitrogen, promoting foliage growth rather than blooms.
“But how do I know the manure is well-rotted?” It should not have a strong smell, to start with, and it should be only humid, not wet.
So, here are the “ingredients” you need for each medium sized climbing rose:
- 2 shovelfuls of well-rotted manure
- 2 cups of rose food (a specially formulated, balanced, but concentrated fertilizer for roses)
- 2 handfuls (or spoonfuls) of Epsom salt
And now you have all the ingredients, this is what you need to do:
- Remove the mulch at the base of your climbing rose. If you haven’t mulched it (bad!), remove only the top inch of soil, and be careful close to the base, not to damage roots.
- Form a shallow saucer, or cup, all around the climbing rose.
- Add 2 shovelfuls of well-rotted manure.
- Add 2 cups of rose food.
- Add 2 handfuls of Epsom salt.
- With a rake, mix them all up roughly.
- Water abundantly.
- Cover with a layer of 2 inches (5.0 cm) of compost.
But how about if you can’t find, or you don’t have, all these ingredients? Well, then you can choose an easy alternative: compost.
How to Fertilize Your Climbing Roses with Compost
Of course, compost is the most common and balanced fertilizer ever, and you may have your own, or you can find it very easily. Well-rotted manure is harder to get, and it may still have a bit of a whiff; though it’s not too bad, it depends on how good and “sensitive” your neighbor’s nose is.
If you choose to use compost to fertilize your roses, especially after each blooming cycle, here’s how to do it:
- Move the mulch to the side.
- Spread about 2 inches (5 cm) of compost around the base of your climbing rose. Yes, be generous!
- Water thoroughly.
- Cover with the mulch again.
It’s as easy as this! As long as you are generous with your compost. And if you have Epsom salt, feel free to mix it in!
Fertilize Climbing Roses with Organic Slow-Release Fertilizers
Maybe you prefer to use a high-quality, organic fertilizer for your garden. Compost might not always be available, especially in urban areas, making organic fertilizers a handy alternative. Just make sure to choose a slow-release type, usually in granular form.
Fast-release liquid fertilizers are best reserved for emergencies, particularly with roses. Ideally, you shouldn’t rely on them regularly. With proper and timely feeding, your roses—whether climbing, rambling, or shrub varieties—will bloom profusely. Espoma Organic Rose-Tone is a fantastic choice for year-round rose care. For show-stopping blooms, especially for climbing roses, consider using a fertilizer with an NPK ratio of 18-24-16, like Miracle-Gro Rose Food. This high-phosphorus formula is excellent for promoting abundant flowers.
The exact amount to use depends on the brand, but typically, one cup per rambling rose is a good rule of thumb. Don’t be stingy—your flowering plants will thrive with generous feeding.
And if you have some Epsom salt handy, toss in a couple of handfuls for an extra boost!
A Final Tip to Keep Your Climbing Roses Blooming
However, feeding your climbing roses at the right time and with the correct fertilizers may not be enough to keep them blooming and reflowering for long… yes, because you need to deadhead all the blossoms once they are spent!
If you don’t, your roses will think, “Job done; I’ve gone to seed,” and they will invest their energy into producing and ripening their hips (their fruits) and they won’t flower as profusely… But if you forget, remember that rose hips are edible, delicious and packed with vitamins C, B and E, as well as fatty acids…
Written By
Adriano Bulla
After many years as an academic in London, Adriano Bulla became a writer, publishing books like A History of Gardening, Organic Gardening and Elements of Garden Design; he then decided to become a gardener, following his childhood dream, and has been following his dream writing and gardening professionally in Southern Europe, where he has specialized in new and innovative organic gardening fields and techniques, like permaculture, regenerative agriculture, food forests and hydroponics.