When to Fertilize Roses: Spring Start plus Last Feeding
When to fertilize roses starts in spring. Iowa State University Extension notes spring is the ideal time to fertilize all roses, just as new growth begins to emerge. Modern roses benefit from more feedings during the first bloom plus in mid to late July. University of Maryland Extension advises no fertilizer after early August.
The short answer
Fertilize roses in spring as new growth emerges. Iowa State University Extension notes modern roses such as hybrid teas, grandifloras plus floribundas benefit from more feedings during the first bloom plus in mid to late July. University of Maryland Extension advises stopping by early August so plants can harden before winter.
What is the rose feeding calendar?
Extension services give a simple season plan.
| Timing | Which roses | Source |
|---|---|---|
| Spring as growth emerges | All roses | Iowa State University Extension |
| First bloom period | Modern roses | Iowa State University Extension |
| Mid to late July | Modern roses | Iowa State University Extension |
| After early August | None | University of Maryland Extension |
Sources: Iowa State University Extension plus University of Maryland Extension.
Why stop feeding by early August?
University of Maryland Extension advises against fertilizing roses after early August. Late feeding pushes soft new growth that does not harden before cold weather. NC State Extension also advises stopping deadheading at the end of summer so plants can begin hardening for winter.
Can too much fertilizer hurt flowering?
Yes. University of Maryland Extension lists excessive lush growth from too much fertilizer among the reasons for poor flowering, plus notes excess fertilizer can cause leaf browning. It advises fertilizing roses when a soil analysis shows a nutrient need. Pale yellow green leaves with stunted growth can point to low nitrogen.
How to: step by step
- Request a soil analysis.
- Feed in spring as growth emerges.
- Water before feeding.
- Feed modern roses at first bloom.
- Feed modern roses in mid to late July.
- End all feeding by early August.
Troubleshooting
Lush leaves but few flowers: too much fertilizer. Feed less often.
Pale yellow green leaves: low nitrogen. Feed through the growing season.
Leaf edges brown: excess fertilizer or heat. Water deeply plus feed less.
For related reading see reading fertilizer numbers, slow release fertilizer for cannabis plus garden microclimates for cannabis. Kind Seed Co also stocks cannabis seeds.
Sources
- Rose care by season, Iowa State University Extension and Outreach
- Rose: identify and manage problems, University of Maryland Extension
- Rosa (rose), NC State Extension Gardener Plant Toolbox
FAQ
Do once blooming roses need extra feedings?
Usually not. Iowa State University Extension notes most roses are fertilized in spring, plus it recommends extra feedings during the first bloom plus in July for modern roses such as hybrid teas, grandifloras plus floribundas. University of Maryland Extension notes some roses bloom only once a year, so one spring feeding suits them.
Is slow release fertilizer good for roses?
Iowa State University Extension notes slow release fertilizers are good options for roses alongside all purpose garden fertilizers. They feed over a longer stretch, which suits a single spring application. Still stop by early August, as University of Maryland Extension advises, so growth can harden before winter.
When is the last feeding for roses?
University of Maryland Extension advises no fertilizer on roses after early August. Iowa State University Extension places the final feeding for modern roses in mid to late July. Stopping then gives new growth time to harden off before frost, which reduces winter damage to soft canes.
Should roses get fertilizer in fall?
No. University of Maryland Extension advises against fertilizer after early August, since late growth is soft going into winter. NC State Extension advises stopping deadheading at the end of summer so plants can begin hardening. Fall care for roses is about cleanup plus mulch, not feeding.
Does soil pH matter for roses?
Yes. University of Maryland Extension notes roses grow well in slightly acidic soil with a pH between 6.0 plus 6.5. Soil pH affects how available nutrients are to the plant, so fertilizer works poorly if pH is off. It advises adjusting pH when a soil analysis recommends it.
