How to Fertilize Rose Shrubs in Spring – Get Your Roses Ready to Bloom!

If you don’t feed your roses like queens in spring, they will sting you later on! No, I am not talking about their thorns (prickles)… The most loved flowering shrub in the world needs some “encouragement” to bloom when it wakes up from dormancy after the cold days of winter, or it will not flower as well as you’d expect. But for a massive, even jaw dropping floral display, think about it: your prized bushes are hungry now, and you need to fertilize them – and well!

Fertilizing rose shrubs the right way and at the right time is essential if you want them to bloom profusely and be the protagonists of your garden they deserve to be.

And roses are quite picky with their food; they need lots, and the right type. So, if you want these bushy beauties to wow you soon, find out how to feed them well now. Are you ready to become a “rose shrub chef”?

When to Fertilize Your Rose Shrubs in Spring

You can’t wait with roses! As soon as winter is over and they get out of dormancy, they are hungry and in need of food. So, you should fertilize your shrubs in early spring. They need time to grow leaves and stems, and lots of energy to be strong and ready to blossom.

If your roses do not feed for about two months before they open their first buds, their blooms will be disappointing – weaker, fewer, smaller and less healthy.

For roses, spring is the “big meal” of the whole year. In this season, is when you’ll have to give them lots of nutrients, so they can keep going for long, more than at any other time of the year, in fact.

You should fertilize your roses just after you have pruned them in spring. So, your two big jobs of the year for these shrubs are now, and you’d better do them together.

Seasons differ from region to region, so, in most places you’ll have to fertilize your roses in March, but this may vary. Use the same rule as we do with pruning then, “feed your rose shrubs when forsythia is in bloom!

If you are late, never mind this time round – act immediately and remember next year…

You will also need to fertilize your rose shrubs later on during spring, and we will see it, but now, let’s think about their “breakfast”.

“Lay the Table” for Your Rose Shrubs Before You Feed Them the “Big Meal”

As we said, roses are aristocracy when it comes to gardening, and you need to “lay the table for them” before you even think about offering your shrubs any food at all. Actually, it’s more like “making a plate for them”, or is it a saucer? Let’s see…

• Remove all the mulch around your sore shrubs.
• Form a shallow saucer around your rose. Do this either by hand (wear gloves if you want, but I prefer it) or with a rake, moving soil from near the rose to further away (about 2 feet or 60 cm for an average shrub, just make sure it reaches the width your shrub had at its peak last year).

Be careful not to damage the roots, so, start about 4 inches from the base (10 cm), and form a ridge at the edge of this circle.

And now, the menu; yes, you have two options…

Rose Shrub “Breakfast” Nr 1 – Compost Based Fertilization

As breakfast is the main meal of the year for rose shrubs, we’ll start with the most common: compost! It’s cheap, easy to find (or make) and to use.

• Lay about 2 inches of compost (5.0 cm) at the base of the rose, filling the saucer you have made.
• You can add a handful of rose food, scattering it over the top.
• You can also add a cup of organic ashes; they will add minerals to your shrub’s diet.
• Keep a few inches from the main stem of the rose though, you don’t want to cover it.
• Water well, and then mulch again (about 2 inches, or 5.0 cm).

This is also a good time to improve drainage, before you mulch, adding 2 inches (5.0 cm) of coarse gardening sand to the compost.

But you have another option…

Rose Shrub “Breakfast” Nr 2 – Manure Based Fertilization

Roses need lots of nutrients, and you can use manure, but you need to choose well:

• Cow manure is ideal, a second best is horse, but do not use chicken or pig, or from any meat eating animal.
• The manure must be fully rotted. It mustn’t be fresh or you will burn your rose and give your shrub too much nitrogen. And how do you know if it’s fully rotted? It should be friable, humid but not wet, and, above all, it must not smell!

Lay some plastic or a tarpaulin sheet on the ground near your roses and prepare the fertilizer there.

• Use 1 shovelful of well-rotted manure per shrub.
• To improve it, add a handful of rose feed.
• For extra minerals, add a cup of organic wood ashes.
• Mix well.
• Fill the saucer with the mix, again, keeping away from the base of your shrub.
• Water and mulch.

With this “recipe” too, you can mix in coarse gardening sand, about half a shovelful per shrub, to improve drainage.

But how about other fertilizers you might have heard of?

Get Your Shrub Roses to Bloom Profusely with Epsom Salt!

Whichever “menu option” you choose, there’s a little secret to get your shrub roses to bloom like crazy: Epsom salt (magnesium sulphate)! And early spring, with their main “meal” is a great time to give it to them.

Yes, because roses start producing new flower buds very early on, about 1 to 3 weeks after you prune them, even if you can’t see them well. Epsom salt takes about 2 weeks to become available to their roots, so, early spring is the best time for it!

Use only a handful or a tablespoon of Epsom salt per shrub; scatter it over or mix it in with the compost or manure. Either way is fine.

With re-blooming varieties, another handful at the end of each wave will boost the next one – keep it in mind…

“Side Dishes” for Your Rose Shrubs’ Big Spring “Meal”

Organic gardeners have become very creative with natural fertilizers, so you may wonder whether you can add others, like bonemeal? The answer is yes, but you need to know why and the dosage. And this is why I’m here!

• Bone meal is great for root growth; use 1 to 2 tablespoons per shrub.
• Blood meal boosts leaf and stem growth; use 1 tablespoon per shrub.
• Alfalfa meal is quite a balanced booster; use 1 to 2 cups per shrub.
• Kelp meal is packed with micronutrients, great for the health, flowers and leaves of your roses; use 1 tablespoon per shrub.
• Worm castings are a powerful all-round fertilizer; use about ½ to 1 cup per shrub.

You shouldn’t use fast-release liquid fertilizers at this stage.

And this is the end of your rose shrubs’ first meal. But…

Follow-Up Spring Fertilization for Your Roses

…But your roses will soon be hungry again! Give them about a month and they will be feeling peckish again… So, you will need smaller but frequent follow up fertilizations…

Again, you have an option with follow up rose feeding after the first month or so…

• A slow-release granular fertilizer every 4 to 6 weeks.
• A fast-release liquid fertilizer every 2 to 3 weeks. I actually prefer to give them half the dose every week, it’s a bit more work, but it keeps the nutrients more stable in the soil.

This “diet” should continue all through spring, into summer and then fall, and you should stop 6 to 8 weeks before the first expected frost.

Compost is fine as a slow-release fertilizer, compost tea or liquid seaweed are excellent natural fast release alternatives, gentle enough to please your rose shrubs’ delicate palate.

Don’t forget a handful of Epsom salt when they start to re-bloom…

But how about the NPK, if you use an off-the-peg fertilizer? Choose 10-10-10 as your usual ratio, but you can switch to 5-10-5 when you see the flower buds on the branches.

This is all, apart from a final tip…

A Final Thought – A Medicine for Iron Deficiency in Roses

If you follow these instructions, your roses will have a healthy diet and be free from the most frequent nutrient deficiencies these shrubs suffer from – and you know, they are pretty sickly in general. Apart from one though, the most common – especially if you don’t add wood ashes to their “breakfast”: iron!

So, if at any stage you see their leaves yellowing, give them a fast-release iron rich fertilizer, like:

• Ferrous sulphate tea (one teaspoon)
• Kelp or seaweed extract (2 tablespoons)
• Molasses solution (2 tablespoons)

Dilute any of these in a gallon of water and irrigate your rose shrub. It will soon recover.

Become a “Rose Shrub Chef” and Enjoy Their Gorgeous Blossoms!

Fertilizing your roses in spring correctly is essential for their health and to get lots of gorgeous flowers. But it is also an art, a bit like cooking. Yes, I know, they are picky and demanding, but now you have all the recipes for healthy meals, you can become a real “rose shrub chef”!

And a final tip… Do play a bit with the ingredients, and see how your rose shrubs respond (you can adapt their diet to your soil, and other growing conditions), and, one day, you may even get a Michelin Star!