Like humans, roses require a healthy diet of nutrients to grow and perform well. However, just as popping too many vitamin pills causes humans to overdose on a good thing, excess use of chemical fertilizers causes soil to overdose on plant food and excrete polluting runoff.
To become fit and flourishing, both people and plants need nutrients from natural sources. The best rose fertilizers combine these nutrients with other essential elements to improve the condition of the soil, as well as feed the plants that grow in it. These recommendations can help you decide which type and brand of fertilizer might work best for your blooms.
- BEST OVERALL: Jobe’s Organics Flower & Rose Granular Fertilizer
- BEST GRANULES: Down to Earth Organic Rose & Flower Fertilizer Mix
- BEST COMPOST TEA: Organic Plant Magic All Purpose Organic Fertilizer
- BEST LIQUID: Neptune’s Harvest Fish Fertilizer 2-4-1
- BEST SPIKES: Jobe’s Organics Rose and Flower Fertilizer Spikes
- ALSO CONSIDER: Espoma Plant-Tone Plant Food
Types of Rose Fertilizer
Rose fertilizer comes in a variety of forms, from spreadable (or sprinkled) varieties to sprays and spikes. The type you should choose depends on your climate; the current condition of your soil and plants; and on how much time, toil, and tender loving care you can afford to give to your garden.
Resembling grains of sand, granular fertilizers look much like the soil they supplement. These fertilizers are scattered over the ground under plants, and then scratched into the soil with the blade of a trowel. Though granular fertilizers are slower to absorb than liquid fertilizers, they last longer, only requiring application once every 4 to 6 weeks.
Rose food composed of natural elements, such as composted manure or bone and feather meals, also helps break up compacted or heavy clay soil, thus improving the movement of air, water, and nutrients. This will make the soil easier to till or dig. Ground that contains organic matter also retains moisture better than that which doesn’t.
Liquid fertilizers, which are designed to be dissolved in water and poured around the base of the plant, will green up plants much more quickly than granular types. But plants on a liquid diet also require more frequent feeding, usually every 1 to 2 weeks.
Since roses must have well-drained ground to flourish, liquid fertilizers could be a problem in areas where the weather is already quite wet; their application could contribute to an overly-soggy soil. Also, the splashing of water around rose bushes should be avoided, since it can spread fungus spores that can, in turn, cause black spot.
Usually dispensed from a hose-end sprayer or spray bottle, spray fertilizers coat plant foliage, which drinks in the nutrients through the leaves rather than through the plant’s roots. They generally require application every 2 weeks.
However, if water adheres to the rose’s leaves for an extended period of time, such as overnight, it can make the plants more vulnerable to fungal diseases. Therefore, growers should spray roses early in the morning to allow them plenty of time to dry off before nightfall. Note that organic mixes tend to be more sludgy than inorganic ones, so they should be shaken frequently to prevent clogging of the sprayer.
Fertilizer spikes, which resemble headless railroad spikes, can be driven into compacted soil with a hammer or pushed into loose soil by a gardener’s fingers. After being evenly spaced out around the base of a plant, they begin to release their fertilizer into the soil slowly over time, enabling a busy gardener to replace them only once every 2 months, or so.
Because spikes can break if hammered into the ground that is too hard, a savvy gardener will dig holes for them instead. Also, since spikes distribute fertilizer only in the area immediately around where they are positioned, the fertilization provided can be somewhat spotty.
What to Consider When Buying Rose Fertilizer
Before purchasing rose fertilizer, consider its NPK ratio, its ingredients, and how easy it will be to apply, including whether or not you must purchase additional tools for that purpose. Also, take into account its possible effects on pets or local wildlife, as well as on the ecosystem of your garden.
The 3-number NPK ratio included in a fertilizer’s description reveals the percentage of its volume given to nitrogen, phosphorus, and potassium. For example, a 3-5-3 formula would include 3 percent nitrogen, 5 percent phosphorus, 3 percent potassium, and 89 percent filler.
Producers of rose fertilizers often consider the middle number the most important one, since phosphorus stimulates flowering and root development. Plant foods with a nitrogen content higher than the other two elements could promote lush foliage growth, but with fewer blooms. Potassium provides plants with the strength to resist stress caused by excessive temperatures, drought, and other harsh conditions.
Organic vs. Non-Organic
Although organic fertilizers generally have lower NPK ratios than chemical types, they incorporate a larger number of microbes, which helps absorption and prevents toxic runoff. Most granular organic fertilizers act more slowly than their chemical counterparts. This means gardeners who want to get their roses growing quickly might want to add a liquid variety in the spring to compensate until the granular food begins to kick in.
One potential disadvantage of organic fertilizers is that their natural ingredients, which often include bone or blood meal, might attract pets or wild animals. What is good for the dirt might not be good for the dog, so gardeners should store all bags out of reach of prying paws.
Ease of Use
Since they will last for 2 months or longer, spikes win the prize for ease of use. Rose fertilization should start in spring, at the time the bushes begin to leaf out, and should stop 4 to 6 weeks before the first fall frost—this prevents the plants from having soft and still-growing foliage at that point. Therefore, most gardeners need only apply spikes a couple of times during the growing season.
With no mixing required, granular fertilizer comes in second on the easiness scale. You simply scoop it straight out of the bag and apply once every 4 to 6 weeks, which equates to about three or four times per year. More time-consuming liquids and sprays require mixing and more frequent application, either weekly or biweekly.
Our Top Picks
The picks below come from known brands and meet the criterion of providing the nutrients roses need while also enriching the soil in which they grow. Continued use of such organic options should eventually better a garden’s soil to the extent that less fertilizer will be required to sustain flourishing plants.
From Jobe’s Organics, this granular fertilizer has healthy fungi and bacteria such as archaea, which cause it to break down in soil quickly. This leads to faster-acting feeding compared with many other organic plant foods. The quick action should eliminate the need for an extra liquid fertilizer to jumpstart rose bushes in the spring.
The fertilizer, which has an NPK ratio of 3-4-3, also contains poultry manure, sulfate of potash, and feather and bone meals. As it only requires application once every 6 weeks, rather than the monthly dose recommended for many organic plant foods, it can save the busy gardener both time and money. It also comes in a bag for easy pouring.
Higher phosphorus generally translates into more blooms, and this flower fertilizer includes a high amount of the nutrient in its ratio. Since the phosphorus in this company’s formula derives from fish bone meal and rock phosphate, it makes a good choice for gardeners wary of bovine bone meal.
That high phosphorus also renders this fertilizer ideal for bulbs of all kinds, including both edible types and those grown for their blooms. Other ingredients include blood and alfalfa meals, as well as seabird guano, humates, kelp meal, and langbeinite (a natural mineral that supplies potassium, magnesium, and sulfur).
Though widely lauded for its beneficial effects, homemade compost tea doesn’t get used as often as gardeners would like; it can be time-consuming to make from scratch.
Fortunately, this compost tea from Organic Plant Magic comes ready to use, providing the benefits of rich organic compost without all the hassle. Following the instructions and simply add the product to the planting hole or mix it with water for use during normal watering.
Organic Plant Magic’s fertilizer contains 55 trace minerals, as well as millions of beneficial microorganisms, for a rise-up-early-in-the-spring brew that gets things growing with probiotics. It can also be used on flowering plants other than roses, making it all plants’ cup of tea.
This fish fertilizer is a ready-made liquid that, once diluted, you can spray directly on your rose’s leaves—and it will be kind to your nose while you do so. Ever since the Pilgrims learned what dead fish could do for plants, gardeners have been wishing that someone would take the stench out of the process.
Neptune’s Harvest developed this fish fertilizer for reduced odor, while leaving in all the nutrients and emulsion ingredients, including vitamins, amino acids, enzymes, and growth hormones. Although the resulting liquid still doesn’t smell quite like a fragrant bath, roses should enjoy soaking it up.
These fertilizer spikes from Jobe’s Organic are designed to supply the same advantages of the company’s granular rose foods in convenient 3-inch spikes. Though they cost more than their granular counterpart, for gardeners opting for convenience, spikes are easier to apply, with no mixing or measuring required. Also, they last about 2 weeks longer, meaning less often fertilization is required. A total of 10 spikes come in one bag.
Gardeners wanting to save money might opt for Espoma’s all-purpose fertilizer, which includes all 15 essential nutrients plus living microbes. Intended for a wide range of plants, this fertilizer has a higher nitrogen level than some rose fertilizers, which could cause too much growth at the expense of bloom.
In addition to roses, Espoma’s product can be used in the rest of the garden for vegetables, trees, shrubs, and other flowers. Its versatility makes this all-purpose fertilizer a solid, affordable choice.
FAQs About Rose Fertilizer
Are you looking for quick and concise answers to your rose fertilization questions? If so, check out the FAQs below.
Q. How do you fertilize roses?
Depending on the type of fertilizer used, you either “scratch” into the soil beneath your plants, pour it into the soil at the bases of those plants, or spray it on their foliage. If you opt for fertilizer spikes, you dig and drive the spike into the ground near the root.
Q. How do you know if roses need fertilizer?
If your plants appear stunted with yellowish, purplish, or burnt-looking leaves, they may be suffering from lack of nutrients.
Q. How often should you fertilize roses?
It varies from once every week to once every two months, depending on the type of fertilizer used.
Q. What is the best time to fertilize roses?
Begin fertilizing in early spring and conclude six to eight weeks before the date of your usual first autumn frost.
Q. What nutrients do roses need most?
Nitrogen, phosphorus, and potassium are considered the most essential nutrients.