Nutrition: timing, dose, results
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 will find CRF and liquid protocols with guideline doses (worked in under the mulch), warning signs (over‑fertilisation, deficiency symptoms), and a separate section for pots and public plantings. Do you tend to apply more feed, or are you worried you’re not giving enough?
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Quick principles Principles & materials Timing Dosing – CRF (slow‑release) Dosing – liquid feed Organic supplements Pots / patio Public and green spaces Signs & troubleshooting Tools you’ll need FAQ
Related: Planting • Watering • Soil & pH • Positioning – private garden • Positioning – pot/patio • Rose not growing? Diagnostics
Quick principles
- Basic rule: fertilise on moist soil, then water in well.
- Season starter: CRF in spring (3–4 months); top‑up after the first main flush of flowers.
- Late summer: focus on K; after mid‑August no N.
- Ring: scatter in a ring 30–40 cm out from the base, not right up against the stem.
- Mulch: feed should go under the mulch – for more even nutrient release.
Own‑root roses – good regenerative capacity; excessive N gives lush but weak growth.
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Principles & materials
- CRF (controlled‑release): 15-9-12 (+Mg+micro) or 16-8-12 for spring; 10-7-20 / 12-8-16 for summer.
- Liquid feed: rose fertiliser in season (every 2–4 weeks) – ideal for quick correction.
- Organic: compost, worm castings, seaweed extract, biochar/zeolite – to improve soil structure and buffering.
Because nutrient uptake depends on pH, measure regularly: Soil & pH.
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Timing
- Spring: from bud‑swelling, apply starter CRF worked into the soil.
- After the first main flush: top‑up (CRF or liquid feed).
- Late summer: focus on K (helps ripen wood).
- Autumn: no nitrogen – it encourages frost‑tender shoots.
The “last nitrogen” cut‑off is typically between about 10–15 August, depending on your climate zone.
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Dosing – CRF (slow‑release)
| Type | Guideline dose / plant | Notes |
| Mini / patio | 15–25 g | In pots, preferably mixed into the compost |
| Hybrid tea / floribunda | 30–50 g | Scatter in a ring and work in shallowly |
| Shrub / English | 40–70 g | Larger shrub = higher dose |
| Groundcover | 25–40 g | Spread evenly over the surface |
| Climber / rambler | 50–80 g | Apply near the support to target the root zone |
- Method: feed should go under the mulch; work in shallowly to 5–8 cm, then water in.
- Soil moisture: do not apply to dry soil – water first.
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Dosing – liquid feed
- Frequency: every 2–4 weeks in season; reduce in very hot weather.
- To the soil: always apply to pre‑moistened soil (for better uptake).
- Strength: follow the manufacturer’s label; in containers use a weaker solution.
Combined with mulch you get more even water and nutrient management: Mulching.
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Organic supplements
- Compost: a 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: improves stress tolerance (after heat/drought).
- Biochar / zeolite: improves buffering, holds water and nutrients (use in small amounts).
pH‑dependence and doses: Soil & pH.
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Pots / patio
- CRF in the mix: 2–5 g/L of compost (added gradually), refresh the top 5–8 cm annually.
- Liquid feed: weaker solution but more often; do not leave water standing in saucers.
- Growing medium: open, airy mix (soil + compost + perlite/pumice); pH changes faster → check more often.
Positioning: Pots / patio • Watering: Watering.
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Public and green spaces
- Protocol: work CRF into the soil in spring, supplement K in summer; use liquid feed only when needed.
- Compost: 2–3 cm under the mulch each year; apply uniformly at bed/border level.
- Operations: check soil moisture before mechanical application; water in via the irrigation system.
Positioning: Public and green spaces.
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Signs & troubleshooting
- Chlorosis (yellow leaf with green veins): iron deficiency / high pH → acidify, add iron.
- Thin shoots, very dark green leaves: too much N → reduce, increase K.
- Scorched leaf edges: over‑application / dry compost → thorough watering, temporary pause in feeding.
- Poor growth despite good watering: lack of organic matter → add compost.
Always fertilise on moist soil; avoid application during heatwaves and in full, scorching sun.
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Tools you’ll need
- CRF rose fertiliser
- Liquid rose fertiliser
- Compost
- Worm castings
- Biochar / zeolite
- Watering can / hose
FAQ
Can I fertilise before rain?
Yes, before moderate rainfall it is helpful; avoid feeding before storms because of leaching.
Which is better: CRF or liquid feed?
They play different roles: CRF is the base supply, liquid feed is for quick corrections. Together they give an even result.
When should I start again in spring?
Around bud‑swelling (depending on local weather), then top‑up after the first main flush of flowers.
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