Nutrient supply for own-root roses – feeding – PharmaRosa®

Nutrients: timing, dosage, results

For roses, a good feeding programme is all about timing: a starter feed in spring, top-ups between flowering flushes, then a potassium-focused regime and nitrogen stop at the end of summer. Here you’ll find CRF and liquid protocols with indicative doses (worked in under the mulch), problem signs (overfeeding, deficiency symptoms), and a separate section for pots and public plantings. Do you tend to overfeed, or are you more worried about underfeeding?

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Quick basics Principles & materials Timing Dosage – CRF (slow-release) Dosage – liquid Organic supplements Pots / terrace Public and green spaces Signs & troubleshooting Tools you’ll need FAQ

Related: Planting • Watering • Soil & pH • Positioning – Private garden • Positioning – Pot/terrace • Roses not growing? Diagnostics

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 feeds: rose fertiliser through the season (every 2–4 weeks) – ideal for quick corrections.
• Organic: compost, worm castings, seaweed extract, biochar/zeolite – to improve soil structure and buffering.

As nutrient uptake depends on pH, test regularly: Soil & pH.

Skip to timing →

Timing

• Spring: from bud swell, work a season-start CRF into the soil.
• After the first main flush: top up (CRF or liquid).
• End of summer: potassium-focused (to help wood ripen).
• Autumn: no nitrogen – it encourages frost-tender growth.

The usual “last nitrogen” cut-off is between about 10–15 August, depending on your climate zone.

Skip to CRF dosage →

Dosage – CRF (slow-release)

• Method: fertiliser should go under the mulch; lightly work it in 5–8 cm deep, then water in.
• Soil moisture: do not apply to dry soil – water beforehand if needed.

Skip to liquid feeds →

Dosage – liquid

• Frequency: every 2–4 weeks in the season; use more sparingly in heatwaves.
• Onto the soil: always apply to pre-moistened soil (for better uptake).
• Rate: 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: 2–3 cm layer under the mulch; improves structure and soil life.
• Worm castings: rich microflora; good at planting and as a surface dressing.
• Seaweed extract: improves stress tolerance (after heat or drought).
• Biochar / zeolite: improves buffering, holds water and nutrients (use in small amounts).

pH dependence and rates: Soil & pH.

Skip to pots/terrace →

Pots / terrace

• CRF in the mix: 2–5 g/L of compost (added gradually), refresh the top 5–8 cm each year.
• Liquid feeds: weaker solution, but more often; don’t leave water standing in saucers.
• Growing medium: open, airy mix (soil + compost + perlite/pumice); pH changes faster → test more often.

Positioning: Pots / terrace • Watering: Watering.

Skip to public and green spaces →

Public and green spaces

• Protocol: spring CRF worked in, summer potassium top-up; liquid feeds only when needed.
• Compost: 2–3 cm under the mulch each year; apply uniformly at bed/plot level.
• Operations: check soil moisture before mechanical application; water in via irrigation system.

Positioning: Public and green spaces.

Skip to signs & problems →

Signs & troubleshooting

• Chlorosis (yellow leaves, green veins): iron deficiency / high pH → acidify, add iron.
• Thin shoots, very dark green leaves: too much nitrogen → cut back, shift towards potassium.
• Scorched leaf edges: overdose / dry compost → thorough watering, temporary pause.
• Poor growth despite good watering: low organic matter → add compost.

Always feed on moist soil; avoid applications during heatwaves and in full blazing sun.

Skip to tools →

Tools you’ll need

• CRF rose fertiliser
• Liquid rose fertiliser
• Compost
• Worm castings
• Biochar / zeolite
• Watering can / Hose

FAQ

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