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

Nutrition: timing, dosage, results

For roses, a good feeding programme is all about timing: a starter feed in spring, a top-up between flushes, then a potassium-focused feed at the end of summer and a nitrogen stop. Here you’ll find CRF and liquid protocols with indicative doses (worked in under the mulch), typical problem signs (overfeeding, deficiency symptoms), and a separate section for pots and public plantings. Do you tend to overdo the feed, or are you more worried you’re not giving enough?

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Quick principles 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 – Pots/terrace • Is your rose not growing? Diagnostics

Principles & materials

• CRF (controlled-release): 15-9-12 (+Mg+micro) or 16-8-12 for spring; for summer 10-7-20 / 12-8-16.
• Liquid feed: rose fertiliser during the 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, test regularly: Soil & pH.

Skip to timing →

Timing

• Spring: from bud swell, work a starter CRF into the soil.
• After the first main flush: top-up (CRF or liquid).
• End of summer: K-focused feed (helps wood to ripen).
• Autumn: no nitrogen – it induces frost-sensitive soft shoots.

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

Skip to CRF dosage →

Dosage – CRF (slow-release)

• Method: fertiliser should go under the mulch; work in shallowly to 5–8 cm deep, then water in.
• Soil moisture: don’t apply to dry soil – water first.

Skip to liquid feeds →

Dosage – liquid

• Frequency: every 2–4 weeks during the season; reduce in heatwaves.
• To the soil: always apply to pre-moistened soil (better uptake).
• Rate: follow the product 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 time and lightly worked into the surface.
• Seaweed extract: improves stress tolerance (after heat/drought).
• Biochar / zeolite: improves buffering, holds water and nutrients (use in small amounts).

pH dependence and dosages: Soil & pH.

Skip to the pots/terrace section →

Pots / terrace

• CRF in the mix: 2–5 g/L of compost (applied gradually), refresh the top 5–8 cm each year.
• Liquid feed: weaker solution but more often; don’t leave water standing in the saucer.
• 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 K top-up; liquid feed only where needed.
• Compost: 2–3 cm under the mulch once a year; apply uniformly across the bed/area.
• 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 N → reduce, switch to K-focused feed.
• Scorched leaf edges: overfeeding / dry medium → heavy watering, temporary break from feeding.
• Poor growth despite good watering: lack of organic matter → add compost.

Always feed on moist soil; avoid application during heatwaves and in full, scorching 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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