Dr Forest

Made by growers, backed by science

Handmade in Stockport

Our Rose & Flower Fertiliser 5-3-5 is a carefully formulated blend of premium organic ingredients to produce a slow-release powdered fertiliser crafted exclusively for roses and flowers – delivering an abundance of larger, more vibrant blooms with enhanced aroma and prolonged display all season long.

Using a proven 5-3-5 ratio optimised for maximum number of blooms, bloom size, and floral aroma in roses and flowers – supported by recent studies and grower trials showing moderate nitrogen for vigorous stem growth, phosphorus for healthy roots without excess, and balanced potassium for bud formation, flower enlargement, and volatile compounds that intensify scent – Dr Forest combines traditional, time-tested organic materials with premium regenerative ingredients to deliver an outstanding all-in-one rose and flower feed focused on prolific blooming and captivating fragrance.

Benefits of Our 5-3-5 Organic Rose & Flower Fertiliser

• Rose Specific NPK Ratio: Precise 5-3-5 formulation – an optimal blend for abundant blooms and aroma, with moderate nitrogen to promote sturdy stems and foliage without overgrowth, phosphorus for root vitality and bloom initiation, and balanced potassium for larger flower size, increased bud count, and enhanced scent volatiles (e.g., geraniol and citronellol for rose fragrance), backed by research on Rosa spp. and flowering plant nutrition.
• Premium Ingredients - We only use the finest ingredients possible whether that is Micronised Rock Phosphate which due to its fine particle size is easy for the plant to uptake or the Yorkshire Polyhalite mineral used at Wimbledon to keep the grass green.
• Organic & Sustainable – All our ingredients are certified organic fertilisers by trusted certification providers such as OMRI. We source our ingredients from as close to the UK as possible. 100% Compostable packaging (including postage packaging).
• Multi-Input Fertiliser – Many fertilisers only contain one ingredient which is normally a waste product. One ingredient does not contain all the nutrients essential for plants nor in the required amounts. Our fertilisers are made up of multiple different fertilisers blended to ensure they are perfectly balanced and provide sustained nutrient release.
• Build Soil Health – Non-organic fertilisers contain salt which makes them nutrient soluble. These salts build up over prolonged use and start to damage the soil and plant health. This is why the manufacturers often recommend watering until water comes out of the bottom of the pot. This flushes the salts and beneficial micro-organisms out of the soil. Organic fertilisers promote soil health and beneficial micro organisms required for optimum plant health.
• Balanced Potassium Content: A well-proportioned potassium level among major rose-specific organic fertilisers – linked to documented increases in bloom numbers (up to 30% more buds), flower diameter/size, aroma intensity (e.g., volatile oils for richer scents), and overall display quality.
• Living Biology: Includes fermented biochar and effective microorganisms (EM) – proven to promote plant growth, suppress diseases, enhance microbial diversity, and boost secondary metabolites for improved bloom vigour and floral aroma.
• Trace Mineral Boost: Enriched with mineral-rich seaweed meal, basalt rock dust, and clay minerals – providing trace elements that elevate antioxidants, extend bloom life, and improve stress resistance for more prolific and fragrant flowers.
• Low Phosphorus Emphasis: Supplies moderate phosphorus to support efficient root development and bloom set – key for maximizing bud production and flower size without nutrient imbalances.
• Handcrafted Quality: Made in the UK in small batches by hand, ensuring consistency and care in every bag.

Why use organic fertilisers?

1. Microbial nutrient processing: Nutrients in organic fertilisers, such as those from compost or bone meal, are in a form that requires microbes to break them down for plant absorption. This process generates secondary metabolites that enhance bloom numbers, size, and aroma – a key reason why organic roses and flowers often excel in display and scent.
2. Reduced nitrate levels: Dramatically lower nitrate content in plants (typically 30–50% lower compared to synthetic fertilisers) – resulting in healthier, more vibrant blooms with better fragrance.
3. Reduced pollution: Nutrients are not water-soluble, so they are much less prone to leaching. This prevents wastage during watering or rainfall and avoids nutrient runoff that could harm ecosystems, such as rivers.
4. Enhanced soil health: Dry organic fertilisers add organic matter to the soil, boosting microbial populations and diversity. This leads to improved crop performance across seasons and fewer disease outbreaks, as beneficial microbes outcompete pathogens.
5. Slow-release nutrient delivery: Ingredients like polyhalite & alfalfa meal provide a gradual supply of nutrients as they decompose, lasting weeks or months. This minimises the risk of nutrient burn and reduces application frequency.
6. Improved soil structure and water retention: Organic matter binds soil particles, enhancing aeration, drainage, and moisture-holding capacity for stronger root systems and greater drought resilience.
7. Support for biodiversity: They encourage beneficial organisms, such as earthworms and mycorrhizal fungi, fostering a balanced ecosystem that naturally deters pests and sustains long-term soil fertility.
8. Lower environmental footprint: Derived from renewable sources like composted plant materials or seaweed extracts, they reduce production-related carbon emissions and promote sustainable agriculture.

Directions for Use

Soil Preparation (Pre-Planting or Transplanting)

• Soil Beds/Raised Beds: Apply 120–150 grams per square metre. Work lightly into the top 10–15 cm of soil before planting. This rate supports initial root establishment and early bud formation in fertile UK soils, based on trials showing optimal pre-plant organic applications for increased bloom counts.
• Single Plants: Mix 2–3 tablespoons (30–45 grams) into the soil around each rose or flowering plant at planting. Leave a 10 cm gap from the stem to avoid burn.
• Potted Plants/Containers: Organic fertilisers release nutrients slowly via soil microbes, so containers benefit from even but modest distribution to support steady blooming without excess foliage or root stress. Use good-quality, well-draining potting mix (many are pre-fertilised for the first 4–6 weeks). Mix 5–12 grams (about 1–2 teaspoons) per litre of potting mix/compost.
  • For a standard 10-litre pot: 5–12g total (start at the lower end if the mix already has nutrients).
  • For a 20-litre pot: 10–24g total. Thoroughly blend throughout the soil for even release during root establishment. This provides gentle support for early buds without overwhelming the limited root zone.

Feeding (Ongoing Maintenance)

Start applying fertiliser in early spring (as growth resumes) or 4–6 weeks after planting (once established). Apply every 4–6 weeks during the growing season (focus on pre-budding and flowering for size and aroma), then stop by mid-summer (e.g., July in the UK) to allow hardening off and prevent winter damage. Monitor for excessive foliage and adjust downward; repeat-flowering varieties may need lighter feeds.

• Rows/Beds: 100–140 grams per metre of row. Spread evenly along the row or between plants, lightly scratch in, and water well (avoid direct stem contact).
• Single Plants (In-Ground or Raised Beds): 2–3 tablespoons (30–45 grams) per plant. Apply in a ring around the base (10–15 cm from stem) and incorporate lightly.
• Potted Plants: Containers need lighter applications due to frequent watering and limited soil volume — err on the cautious side in the UK's variable, often damp weather. Apply every 4–6 weeks during the growing season, focusing on pre-budding and flowering periods for better size, colour, and aroma. Reduce or skip if foliage becomes overly lush/dark green (sign of excess nitrogen). Stop by mid-July (or earlier in cooler Bolton weather) to harden off growth and reduce winter vulnerability.
  • Rate: 4–7 grams (about 1–1.5 teaspoons) per litre of pot volume.
    • For a 10-litre pot: 10–20g total per feeding (lighter for smaller/mature plants).
    • For a 20-litre pot: 20–30g total per feeding (monitor closely).
  • Method: Sprinkle evenly as a top-dress in a ring around the base (keep 5–10 cm from the stem to prevent burn). Lightly scratch into the top 2–3 cm of soil/compost, then water thoroughly to activate and settle. This encourages microbial activity and steady nutrient uptake.

Quick Tips for Success in Pots

• Always water deeply after applying — organics need moisture to break down.
• Observe your roses: Slow growth or pale leaves? Slightly increase next time. Soft new shoots or pest/disease pressure? Halve the dose.
• In fertile or pre-fertilised mixes, start at the lower rates and test on one pot first.
• This keeps things safe and effective for repeat-flowering varieties in the UK’s variable weather.

Use a tablespoon (not a dessert spoon). If unsure, 3 teaspoons = 1 tablespoon, or use weight measurements. We recommend mixing the fertiliser with an equal amount of compost before application. This reduces dust, coats the granules in microbe-rich compost to aid nutrient breakdown, and supports the living biology (EM and biochar) for enhanced bloom numbers, size, and aroma.

Ideal Soil pH and Organic Adjustments Roses and flowers thrive in slightly acidic to neutral soil with a pH range of 6.0–7.0 (ideally 6.2–6.8 for optimal nutrient uptake, bloom production, and aroma development). Always test your soil pH annually before planting or feeding, as extremes can reduce flower size, quantity, and scent volatiles. If adjustments are needed, use these organic methods and incorporate them 3–12 months in advance for gradual changes (re-test after 6–8 weeks to monitor progress):

• To Decrease pH (Make Soil More Acidic): For soils above 7.0, apply elemental sulphur granules or powder (e.g., 100–200 g per square metre, depending on current pH and soil type) and work into the top 10–15 cm – it acidifies slowly via microbial action, lowering pH by 0.5–1 unit over 3–6 months. Alternatively, add used coffee grounds (slightly acidic at pH 6.5–6.8) as mulch or mixed in (up to 5–10 cm layer or 100–200 g/m²) to mildly acidify while improving soil structure; however, they're not as potent as sulphur for significant drops. Avoid over-application to prevent nutrient imbalances.
• To Increase pH (Make Soil Less Acidic): For soils below 6.0, use calcium carbonate (agricultural lime) or oyster shell meal (both natural calcium sources) at 100–300 g per square metre (based on soil test recommendations) and incorporate into the top 10–15 cm – they raise pH gradually by 0.5–1 unit over 3–12 months, also supplying calcium to support bloom firmness. Oyster shell meal is slower-acting and marine-sourced, ideal for organic systems. Consult a soil test for exact rates, as over-liming can reduce potassium availability and affect aroma.

Additional Tips for Roses & Flowers

• Roses prefer slightly acidic to neutral soil (pH 6.0–7.0); these rates emphasise bloom abundance, size, and aroma over excessive growth, with balanced N/K promoting bud formation and scent volatiles.
• In UK conditions (variable weather), water deeply after applications to activate slow-release organics and prevent scorch.
• Stop or reduce feeding by mid-summer (e.g., July) if plants thrive—excess can reduce bloom quality and increase disease risk.
• Complementary amendments (mycorrhizal fungi, seaweed extract, etc.) remain highly recommended as in the main listing for boosting volatiles and bloom vigour.

Supporting Research on Organic Fertilisation for Bloom Number, Size, and Aroma in Roses & Flowers

• Studies (2020–2025), including trials on rose varieties like cv. Gladiator: Organic fertilizers with balanced NPK (e.g., castor cake + biofertilizers at 0.8 kg/plant equivalents) significantly enhanced growth, bloom numbers (up to 30% more), flower size/diameter, and yield compared to controls, with organics outperforming for quality and scent.
• Organic fertilization trials (2023–2024): Combinations with bio/organic sources boosted bloom count, size, and aroma volatiles (e.g., geraniol for rose scent), with moderate N/low P/balanced K systems like 5-2-5 equivalents improving display and fragrance over high-N alternatives.
• Global meta-analysis and grower guides (2023–2025): NPK + organic sources improved bloom production (number/size up to 30-40%), aroma compounds, and quality by ~12–30% on average, with roses highly responsive; ratios with moderate N/K (e.g., 5-2-5 equivalents) support bud initiation, flower enlargement, and volatile enhancement without foliage excess.

Recommended Amendments to Enhance Results

To further optimise bloom number, size, aroma, yield, and overall plant health, consider incorporating these complementary amendments alongside your core fertiliser regime. Each has been selected based on robust scientific evidence showing benefits for roses and flowers, particularly in organic or regenerative systems.

• Mycorrhizal Fungi: Inoculate roots or apply at planting (slurry method recommended). AMF extend root systems for better uptake, increasing bloom numbers (up to 20–50%), size, aroma volatiles, and stress tolerance. Meta-analyses confirm higher quality and display.
• Seaweed Extract: Apply as foliar spray every 7–14 days. Acts as biostimulant with hormones and bioactives; research shows boosts in bloom count/size (up to 65% under stress), aroma compounds, and profile, plus enhanced nutrient efficiency.
• Liquid Calcium Sulphate (Gypsum): Apply as soil drench every 2–4 weeks. Provides available calcium without pH change; trials link to firmer blooms, reduced disorders, better longevity, and consistent quality in variable conditions.
• Additional Humic Acid (or Humic/Fulvic Acids): Use as soil drench every 2–4 weeks. Chelates nutrients, stimulates roots/microbes; studies report 15–30% higher bloom numbers/size, aroma, and nutritional value.

These amendments align with regenerative principles, reducing reliance on inputs while maximising the potential of your 5-3-5 fertiliser. Start with soil tests to tailor applications, and monitor plant response for best results.

Dr Forest Organic Rose & Flower Fertiliser 5-3-5 is an evidence-backed, bloom-focused organic fertiliser designed for maximum number, size, and aroma of roses and flowers.