Dr Forest

Made by growers, backed by science

Handmade in Stockport

Our Tomato Fertiliser 3-4-6 is a carefully formulated blend of premium organic ingredients to produce a slow-release powdered fertiliser crafted exclusively for tomatoes that taste like tomatoes should – intensely sweet, rich, and complex, with heavy, consistent harvests all season long.

Using a proven 3-4-6 ratio that has performed strongly in grower comparisons and research for over 30 years, Dr Forest combines traditional, time-tested organic materials with premium regenerative ingredients to deliver an outstanding all-in-one tomato feed.

Benefits of Our 3-4-6 Organic Tomato Fertiliser

• Balanced NPK Ratio: Precise 3-4-6 formulation – an optimal blend for superior flavour and yield, supported by extensive research on tomato nutrition.
• High Potassium Content: One of the highest potassium levels among major tomato-specific organic fertilisers – linked to documented increases in Brix levels, lycopene, vitamin C, and taste-panel scores for exceptional fruit quality.
• Living Biology: Includes fermented biochar and effective microorganisms (EM) – proven to promote plant growth, suppress diseases, and enhance microbial diversity.
• Trace Mineral Boost: Enriched with mineral-rich seaweed meal, basalt rock dust, and clay minerals – providing trace elements that enhance antioxidants, extend shelf life, and improve stress resistance.
• High Calcium Content: Supplies ample calcium to support robust plant health and prevent blossom end rot – particularly valuable as calcium is often limited in some fertiliser types.
• Premium Composition: A blend of 13 premium plant-based ingredients, including Yorkshire Polyhalite and Scottish Seaweed. 
• Superior Harvest Results: Heavier crops of firmer, more uniform fruit with 15–25% longer shelf life compared to higher-nitrogen alternatives.
• Handcrafted Quality: Made in the UK in small batches by hand, ensuring consistency and care in every bag.
• Versatile All-in-One Solution: A single, convenient product suitable from transplant to final harvest – ideal for garden beds, raised beds, containers, and polytunnels.

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 flavour and aroma – a key reason why organic produce often excels in taste, scent, and nutrient density.
2. Reduced nitrate levels: Dramatically lower nitrate content in fruit (typically 30–50% lower compared to synthetic fertilisers) – resulting in cleaner, healthier, and better-tasting tomatoes.
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

• Soil Beds: 150 grams per square metre. Work into the top 10–15 cm of soil surface.
• Single Plants: Mix 3 tablespoons (45 grams) into the soil around the plant when planting. Leave a 10 cm gap between the stem and the fertiliser ring.
• Potted Plants: Mix 1 tablespoon (15 grams) per litre of soil. Mix thoroughly.

Feeding

Start applying fertiliser 10–14 days after planting. Apply every 2 weeks.

• Rows: 165 grams each side per metre of tomato plants.
• Single Plants: 3 tablespoons (45 grams) per plant.
• Potted Plants: Apply 1.5 teaspoons (6–7 grams) per litre of soil.

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 and coats the granules in microbe-rich compost to aid nutrient breakdown.

Supporting Research on Organic Fertilisation for Flavour and Yield

• Gao et al. (2023) meta-analysis of 107 studies (Applied Sciences): Organic fertilisers significantly increased vitamin C by ~19% and lycopene by ~24% compared to no fertiliser, contributing to improved nutritional quality and flavour.
• Multiple studies (2021–2024), including meta-analyses in European Journal of Agronomy and Scientia Horticulturae: Higher potassium-to-nitrogen ratios support gains in sweetness, aroma compounds, and sensory scores, often with minimal yield penalty.

Recommended Amendments to Enhance Results 

To further optimise flavour, 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 tomatoes, particularly in organic or regenerative systems.

• Mycorrhizal Fungi: Inoculate seedlings or apply at planting. We recommend the "slurry method." AMF form a symbiotic relationship with tomato roots, extending the root system for better nutrient and water uptake. Studies show AMF inoculation increases fruit yield (up to 20–50% in some trials), enhances soluble solids (Brix levels for sweetness), boosts lycopene (up to 24–53%), vitamin C, and aroma compounds, while improving drought tolerance and disease resistance. Meta-analyses and field trials confirm higher antioxidant content and sensory scores in mycorrhizal tomatoes.
• Seaweed Extract : Apply as a foliar spray. Apply every 7-14 days. Seaweed extracts act as bio stimulants, rich in natural growth hormones, trace elements, and bioactive compounds. Research demonstrates increases in yield (up to 65% under stress), fruit set, soluble solids, lycopene, flavonoids, and overall flavour profile. They also enhance stress resilience (drought, salinity) and nutrient efficiency, with meta-analyses supporting improved sweetness, aroma, and nutritional quality.
• Liquid Calcium Sulphate (Gypsum): Apply as a soil drench. Use every 2-4 weeks. Gypsum supplies readily available calcium without altering soil pH, crucial for cell wall strength. Extensive trials link gypsum application to reduced blossom end rot (a common calcium-deficiency disorder), firmer fruit, better shelf life, and maintained yields. It supports consistent fruit development and quality, especially in variable moisture conditions.
• Additional Humic Acid (or Humic/Fulvic Acids): Use as a soil drench. Apply every 2 - 4 weeks. Humic acids chelate nutrients for better uptake, stimulate root growth, and enhance microbial activity. Studies report yield increases (up to 19–30%), higher Brix/sugar content, improved nutrient density (e.g., antioxidants), and stress tolerance. They complement slow-release organics by boosting efficiency and fruit flavour/nutritional value.
• Cover Crops (e.g., Rye, Radish, or Legume Mixes): Sow in autumn/winter before tomatoes, then incorporate as green manure in spring. Cover crops build soil organic matter, improve structure, and suppress diseases. Long-term trials show higher tomato yields (equivalent or greater than bare soil), enhanced soil health indicators, and reduced foliar/fruit diseases (e.g., anthracnose).

These amendments align with regenerative principles, reducing reliance on inputs while maximising the potential of your 3-4-6 fertiliser. Start with soil tests to tailor applications, and monitor plant response for best results.

Dr Forest Organic Tomato Fertiliser 3-4-6 is an evidence-backed, flavour-focused, high-yielding organic tomato fertiliser.