Nutrition: timing, dose, result
For roses, a good feeding programme is all about timing: a starter feed in spring, top-ups between flushes of flowers, then a potassium‑focused feed at the end of summer and a nitrogen stop. Here you’ll find a CRF and liquid protocol with indicative doses (worked in under the mulch), warning signs (overfeeding, deficiency symptoms), and separate sections for pots and public plantings. Do you tend to overfeed, or are you worried you’re not giving them enough?
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Quick principles Principles & materials Timing Dosing – CRF (slow‑release) Dosing – liquid Organic supplements Pots / terrace Public and green spaces Signs & troubleshooting Required tools FAQ
Related: Planting • Watering • Soil & pH • Positioning – Private garden • Positioning – Pots/terrace • Roses not growing? Diagnostics
Quick principles
- Basic rule: always fertilise on moist soil, then water in.
- Season start: spring CRF (3–4 months); top‑up after the first main flush of flowers.
- Late summer: K‑focused feed; no N after mid‑August.
- Ring: scatter in a ring 30–40 cm out from the stem, not right up against it.
- Mulch: fertiliser should go under the mulch – gives more even release.
Own‑root roses – good rejuvenation; too much N gives lush but weak growth.
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Principles & materials
- CRF (controlled‑release): 15-9-12 (+Mg+micro) or 16-8-12 in spring; for summer 10-7-20 / 12-8-16.
- Liquid: rose feed during the season (every 2–4 weeks) – ideal for fast correction.
- Organic: compost, worm castings, seaweed extract, biochar/zeolite – to improve soil structure and buffering.
Because nutrient uptake depends on pH, regular testing is important: Soil & pH.
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Timing
- Spring: from bud‑swell, work a starter CRF into the soil.
- After the first main flush: top‑up (CRF or liquid).
- Late summer: K‑focused feed (helps ripening and wood formation).
- Autumn: no nitrogen – it promotes soft growth that’s vulnerable to frost.
The “last nitrogen” deadline is typically between 10 and 15 August, depending on climate zone.
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Dosing – CRF (slow‑release)
| Type | Indicative dose / plant | Note |
| Mini / Patio | 15–25 g | In pots preferably mixed into the compost |
| Hybrid tea / Floribunda | 30–50 g | Scatter in a ring, lightly worked in |
| Shrub / English | 40–70 g | Bigger bush = higher dose |
| Groundcover | 25–40 g | Spread evenly across the surface |
| Climber / Rambler | 50–80 g | Apply at the base of the support, targeting the root zone |
- Method: fertiliser should go under the mulch; work in shallowly 5–8 cm deep, then water in.
- Soil moisture: do not apply to dry soil – water first.
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Dosing – liquid
- Frequency: every 2–4 weeks in the season; use more sparingly in heatwaves.
- To the soil: always apply to pre‑moistened soil (better uptake).
- Rate: as per manufacturer’s label; in containers a weaker concentration is recommended.
Combined with mulch you get more even water and nutrient management: Mulching.
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Organic supplements
- Compost: 2–3 cm layer under the mulch; improves structure and soil life.
- Worm castings: rich micro‑life; good at planting time and as a surface dressing.
- Seaweed extract: boosts stress tolerance (after heat/drought).
- Biochar / zeolite: improves buffering, holds water and nutrients (in small amounts).
pH dependence and doses: Soil & pH.
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Pots / terrace
- CRF in the mix: 2–5 g/L compost (gradually), refreshing the top 5–8 cm each year.
- Liquid: weaker concentration but more often; do not leave water sitting in the saucer.
- Growing medium: open, airy mix (soil + compost + perlite/pumice); pH changes faster → test more often.
Positioning: Pots / terrace • Watering: Watering.
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Public and green spaces
- Protocol: spring CRF worked in, summer K top‑up; liquid feeds only when needed.
- Compost: 2–3 cm under the mulch each year; apply uniformly across the bed/area.
- Operations: check soil moisture before mechanised spreading; water in via the irrigation system.
Positioning: Public and green spaces.
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Signs & troubleshooting
- Chlorosis (yellow leaf, green veins): iron deficiency / high pH → acidify, add iron.
- Thin shoots, very dark green leaves: too much N → reduce, shift to K‑focused feed.
- Scorched leaf edges: over‑application / dry compost → heavy watering, temporary pause.
- Poor growth despite good watering: lack of organic matter → add compost.
Always fertilise on moist soil; in heatwaves and full, scorching sun avoid applying fertiliser.
Go to tools →
Required tools
- CRF rose fertiliser
- Liquid rose fertiliser
- Compost
- Worm castings
- Biochar / zeolite
- Watering can / Hose
FAQ
Can I fertilise before rain?
Yes, before moderate rain it’s useful; before a storm it should be avoided because of leaching.
Which is better: CRF or liquid?
They have different roles: CRF is the base supply, liquid feed is for quick correction. Together they give an even result.
When should I start again in spring?
Around bud‑swell (according to local weather), then top‑up after the first main flush of flowers.
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