When Is Best To Fertilize Roses?

Last Updated on November 9, 2022 by Stephanie

In general , roses are tough plants that can withstand any kind of weather, however theyre heavy eaters, and consequently a proper fertilization program when it is time to do so will result in the most healthy roses with the largest quantity of blooms.

Begin to fertilize roses in April/May using Potash, nitrogen, and phosphate fertilizer like fish emulsion. Reapply every month up to August 15th. Bone meal and Alfalfa can be combined with the fish emulsion, and applied once every 4 to 6 weeks for optimal results.

The reason to stop fertilizing after August 15th is because the rose leaves require time to get ready for its period of winter dormancy. The nitrogen contained in fertilizers stimulates the growth of new soft plants, which are especially susceptible to damage from frost.

I suggest using a mulch like compost, well-rotted horse manure, or leaf mould to your roses towards the beginning of spring to help activate the soils ecosystem. You can also add another layer of mulch prior to winter, to protect the roots from the harshest winter chill.

The roses thrive when they have a balanced diet that is, mixing fertilizers and using them together. This will ensure that the soils ecology is healthy and that the roses get every nutrient they require to thrive and to produce the highest quality flowers.

When you feed roses, the most effective results are achieved with the variety.

When to use Liquid Fertilizers for Roses

The emulsion of fish can be applied to the rose bed from the late April-early May timeframe (or up to the point that theres less risk from frost) and then a one month application is possible alongside other fertilizers up to the mid-August.

Fish emulsion is fast and effective fertilizer that can penetrate the soil and get to the roots faster than fertilizers in the form of granulated.

The emulsion of fish is also high in nitrogen, which is excellent to encourage growth and promoting green the foliage. This could be a problem but only if the weather is cold enough as the new growth that is softer is more prone to damage from frost.

Make sure to wait until at least the end of April or early May, after the new leaves are fully open. Only apply when the nights are consistently warming. If theres an early frost, the new growth could be okay, but should you notice any damaged leaves (leaves which have turned black) you can remove the growth with pruning tools so that your flower will be good.

The emulsion of fish needs to be mixed into the watering container using an amount of around 1 tablespoon per gallon water. A typical watering container is able to hold 2 gallon. It can be used to water one or two rose bushes that are established to provide a increase in nitrogen, phosphorous , and potassium that are the main nutrients required in large quantities by roses.

Phosphorus is believed to be responsible for stimulating the development of stems, roots and promoting flowering for robust and healthy roses.

Potassium is a valuable ingredient for your rose bush because it encourages bigger flowers and increases the resistance of plants to drought and other common diseases.

The fish emulsion is an excellent fertilizer that can help in stimulating soils ecology and feeding directly your nutritional needs, but its considered to be a short-term fertilizer that should be used together with other slow releases fertilizers (such as blood and alfalfa, or bone meal) broad range of nutrients.

If you apply it once per month, you can ensure a healthy and disease-resistant rose that will put on a stunning flower display.

Stop applying the emulsion to fish in the month of August since the growth that nitrogen encourages requires time to set and prepare for the coming winter.

Take note that the scent of fish can draw flies, cats and even dogs if its not thoroughly cleaned out, therefore make sure to give your rose a thorough bath after applying.

The application of mulch like compost, around the plants base will aid in neutralizing the smell and keep insects out.

It isnt necessary to do any work and thus avoid damaging the roots.

Short term fertilizer

The fertilizers are incorporated into the soil are broken down and added to the soils ecology. They gradually release nutrients.

Liquid fertilizers are quick to take effect and leach away. Quick abundant of nutrients, leak off into soil, add to the watering cans every month. More effort

When to Apply Rose Formula or Chemical Fertilizers

The suggested application of any chemical or rose-based fertilizers will differ in accordance with the manufacturers instructions that you must always consult prior to using.

The general rule is applying a fertilizer chemical after youve pruned your roses in spring, and to apply another following your first flower. In some cases, a third application is suggested prior to your second flower.

But I would like to emphasize the importance of adhering to manufacturers guidelines since too much chemical fertilizer could cause the root that you have planted, therefore make sure you are careful.

roses on bush

Over fertilization can cause more harm than none ever did, so dont be attracted to fertilize too much because it wont produce the results youre looking for.

My personal favorite Rose formula is the miracle blend for growing roses. The pre-made mix contains all the essential nutrients that required by roses in the correct levels. The granules need to be applied twice throughout the growth season, first at the beginning of spring in May or April and after that in July.

I personally apply this fertilizer because its extremely easy to use and has resulted in healthy, beautiful roses that are filled with blooms. Its the ideal, simple rose fertilizer.

When to fertilize with Alfalfa as well as Bone Meal for Roses

It is possible to begin adding bones meal as well as Alfalfa fertilizers to your roses as early as April. You can continue applying them every 4to six weeks up to August 15 15th at which point no new growth is expected as the rose is getting ready for winter hibernation.

The bone meal and Alfalfa complement the use of fish emulsions as they both breakdown and let out fertile soil into the soil at a slower rate and also feed soil microbes, and enhance the soils structure to allow to improve drainage and improve the soils ability to retain the proper amount of water.

The emulsion of fish reaches the root quickly, but it also drains out into the soil quickly , whereas alfalfa and bone meal feed your soil for a long time to ensure an easier releases of nutrition.

Fertilizing using alfalfa and bone meal is a breeze and both provide an abundance in nutrients like zinc, magnesium, nitrogen iron, calcium, and potash. All of these aid in the health and resistance to disease of roses.

Alfalfa also has a growth stimulant known as triacontanol that increases the break in the basal of rosebushes to allow for new growth and, consequently, more flowers.

Bone meal is known to smell , and alfalfa is consumed by wild rabbits, so its an excellent idea to sweep the mulch around your rose. Spread the granules on the base of your rose. Then, sweep the mulch over the top, before giving it an extensive soak using your hosepipe.

This will eliminate any unpleasant odors and allow food and the granules to begin to break down into the soil until they can reach the root and are not eaten by animals.

When to Mulch for Healthy Roses

It is possible to add mulch around your roses anytime of the year without worrying about encouraging the growth of new plants too early or later during the growing season. While mulch can add fertilisation to your soil however, it will break down slowly as it ages away from the soils surface instead of getting to the roots in a hurry as the case with liquid fertilizers.

In addition, the focus is more on feeding the soil and improving it so that the roses can benefit instead of feeding directly to the roses roots.

Organic matter like horse manure leaf mould, compost and horse manure are all great mulches since they do not just release nutrients into the soil, but also:

  • Improve soil structure so that water drains more easily, and roots be able to move more easily through the soil to get access to water and nutrients.
  • Cools the soil in summer (roots prefer cooler temperatures)
  • Keeps the soil ecology and worms active as they eat the organic matter that is decaying and break it down into a chelated form which is rich in nutrients, making it much easier for plants to absorb.
  • Mulch is superior in its capacity to hold and absorb water than most soils, so that the roses roots can draw on moisture whenever they need to.

Healthy soil means healthy roses So always give your rose a thorough application, or two every year.

The ideal time to put mulch in is:

  1. The beginning of growing season in spring, typically in March, to improve soil ecologically.
  2. Another layer of mulch is appreciated by your roses when the temperatures in summer are hot and the soil is hot and cracks. The rose roots prefer to stay cool, and a the mulch layer will reduce temperatures of underlying soil.
  3. A mulch application in the winter months will be beneficial for the well-being of your rose because it will protect the roots from the harshest of winters cold and will give the roots the chance to get a head start in spring.

Place a 2 inch layer of mulch to the base of your rose , making sure that the mulch does not come touching one of your canes (3 inches is ideal) because the roses plants wood above ground is not a fan of continuous exposure to water.


Mulch can be used at any time of the year to provide an excellent boost to fertility as well as an opportunity to improve soil structure.

Apply fertilizer in spring shortly before the leaves fully open. Apply it once every 4-6 weeks throughout the growing season to create the most beautiful flowers.

Whatever fertilizer you decide to use, ensure that you do not apply them too soon or late (before April and after 15 TH) because it can encourage growth in the time that your roses are getting prepared for cooler temperatures.

The process of alternating your fertilizers will ensure that your flower and the soil gets all the nutrients they require to grow healthy and disease-resistant roses. They also have abundant flowers.



Went from an inexperienced gardener to a half-decent one over 10+ years. I cover anything from general indoor plant guides and lawn care, to succulents and flowers. Super happy to share my tips and tricks with you :)