Mills

Mills Nutrients is a Dutch brand specializing in bio-mineral fertilizers, born from Dutch agricultural tradition and over twenty years of research in the laboratory and under real-world conditions. Mills formulas utilize both organic and mineral sources to combine the quality of organic fertilizers with the precision and rapid absorption of mineral fertilizers. This approach limits nutrient buildup in the substrate, while allowing plants to reach their full potential without sacrificing taste or aroma.

The range is designed for all types of cultivation: soil, coco coir, hydroponics, and automated systems, from small indoor gardens to professional setups. Mills offers complete nutrient bases, flowering boosters, root stimulants, and additives to ensure optimal growth, flowering, and harvest quality.

Main Mills products

• Basics A & B This two-part nutrient base provides all the necessary macro and micronutrients, suitable for use during both the vegetative and flowering stages, in soil, coco coir, or hydroponics. Formulated with high-quality ingredients and a strong focus on bioavailability, it simplifies fertilization management for both beginners and advanced growers.

• Start-R An organo-mineral starter stimulant and root booster, enriched with nitrogen, humic and fulvic acids, amino acids, and algae-derived biostimulants, suitable for use in soil, coco coir, and hydroponics. It promotes a dense and active root system, essential for rapid growth and abundant flowering.

• C4 A flowering booster that accompanies the stretch and early flowering stages, optimizing flower formation and nutrient absorption. When used with Basis A&B, it helps increase the number of flowering sites and bud density.

• Ultimate PK A late-flowering PK booster, rich in phosphorus and potassium, designed to swell flowers, densify fruit, and improve final yield. It is formulated for rapid absorption without unnecessarily overloading the substrate.

• Vitalize This additive, based on silicon and trace elements, strengthens plant structure, stimulates photosynthesis, cell division, and the immune system, reducing the need for pesticides. It results in greener plants, greater resistance to stress (heat, drought, disease), and more abundant and higher-quality harvests.

• Mills substrates (e.g. Coco & Cork) Mills also offers substrates like Coco & Cork, a blend of 75% RHP coco coir and 25% fine cork, providing excellent aeration and optimal root development. These substrates are designed to work in synergy with Mills fertilizers and modern growing systems.

FAQ – Questions and Answers about Mills Fertilizers

1. What differentiates Mills from other fertilizer brands?

Mills is a pioneer in bio-mineral fertilizers , combining organic and mineral sources in optimized ratios for rapid absorption and excellent final quality. Their formulas are the result of years of research and testing with hobby growers and in professional greenhouses, guaranteeing reliable and reproducible results. Unlike some 100% mineral fertilizers, Mills formulas limit salt buildup in the substrate, allowing plants to grow to great heights without burning or nutrient lockout, provided the feeding schedule is followed.

2. Are Mills fertilizers suitable for indoor growing (growbox, LED, hydro, etc.)?

Yes, the range was designed to work in both indoor and outdoor growing, but it is particularly popular with indoor growers, whether using LED or HPS lighting. Basis A&B bases and additives are tested in soil, coco coir, and hydroponics, making them compatible with all systems (pots, ebb and flow systems, DWC, NFT, drip irrigation, etc.). Their bio-mineral composition allows plants to respond quickly to dosage adjustments, which is an advantage in a controlled environment.

3. On which substrates can I use Mills (soil, coco, hydroponics)?

Mills fertilizers can be used on:

• Potting soil (pots, containers, beds)

• Coco (coconut pots, slabs, soil/coconut mixes)

• Hydroponic and recirculating systems

Products like Basis A&B are specifically tested on these three substrate types, with high stability and bioavailability. Mills also offers its own substrates, including Coco & Cork, for those who want an optimized fertilizer + growing medium combination.

4. How to use Basis A&B (dosage and phases)?

Basis A&B is a two-part base to be used from the beginning of growth until the end of flowering, with a gradual dosage depending on the plant's stage. The principle is to always mix A and then B separately in water, following the Mills feeding charts and adjusting the conductivity (EC) to your growing method and the needs of your strain. Both parts provide all the essential macro and micronutrients, which avoids the need for multiple base products and simplifies monitoring.

5. What is Start-R used for and when should it be applied?

Start-R is used from the very first days of plant life (seedlings, cuttings, young plants) and at the beginning of growth to boost root and vegetative development. Its composition of nitrogen, humic/fulvic acids, amino acids, and algae biostimulants improves nutrient absorption and the young plant's stress tolerance. It is compatible with all substrates (soil, coco coir, hydroponics) and can be combined with the rest of the Mills range if the dosages are respected.

6. What is the difference between C4 and Ultimate PK?

C4 is designed for the transition and early flowering phase: it helps the plant develop a maximum number of flowering sites and optimize nutrient absorption at this crucial time. Ultimate PK is a late-flowering PK booster, more concentrated in phosphorus and potassium, which helps to densify flowers/fruits, improve dry weight, and enhance harvest quality. The two products are complementary and fit within the Mills feeding schedule to support the entire flowering stage without overloading the substrate.

7. What does Vitalize bring to my crop?

Vitalize is a stabilized silicon and trace element-based additive that strengthens cell walls, plant structure, and overall health. It stimulates photosynthesis, cell division, and protein synthesis, resulting in greener leaves, stronger stems, and improved resistance to diseases and pests. In practice, growers often observe increased vigor, reduced stress, and higher yields.

8. Does Mills offer an organic/vegan range?

Mills has developed an organic and vegan line for growers who want to avoid chemicals while maintaining high performance. This range allows for the production of high-quality harvests, meeting organic standards while remaining easy to use. It follows the same scientific nutrition principles, but with 100% organic and plant-based sources. ​

9. What is the shelf life of a Mills nutrient solution once mixed?

According to Mills recommendations, a freshly prepared nutrient solution typically lasts 24 to 48 hours. Beyond this timeframe, oxygenation decreases, the stability of certain components may degrade, and the risk of microbial growth increases, especially in warm environments. It is advisable to stir the solution well, keep it away from light, and regularly test the pH/EC.

10. What pH should be targeted with Mills fertilizers?

Mills recommends aiming for an optimal pH tailored to the substrate: slightly acidic for soil and coco coir, and a bit more precise for hydroponics, to ensure maximum nutrient availability. The brand offers pH Up/Down correctors to adjust the solution and maintain the ideal range indicated on their growing charts. Regular pH monitoring is particularly important in hydroponic systems and with hard water.

11. How do I dose Mills according to my level (beginner / advanced)?

For a beginner grower, the simplest approach is to follow the Mills chart corresponding to their substrate and water type (soft/hard), without exceeding the recommended dosages. Since the formulas are balanced, this allows for excellent results without having to correct deficiencies one by one. Advanced growers can then fine-tune the formula based on the strain, the EC of the starting water, and the plants' recovery (slight under-feeding initially, then gradually increasing the dosage).

12. Is Mills suitable for demanding crops (cannabis, tomatoes, chili peppers, herbs)?

Mills fertilizers are widely used on high-value crops like cannabis, but also on tomatoes, peppers, strawberries, herbs, and ornamental flowers. The combination of complete bases and targeted boosters allows for the full expression of genetic potential in terms of vigor, yield, essential oil content, and aroma. Many growers report denser buds, tastier fruit, and an improved aromatic profile compared to generic lines.

13. Are Mills products easy to integrate into an automated routine (watering, irrigation)?

Yes, Mills fertilizers are stable liquid solutions that are well-suited to automatic irrigation systems, drip irrigation, and pumped reservoirs. Simply follow the mixing order, stir well, monitor pH/EC, and adhere to the recommended pot life (24–48 hours). In automated indoor growing, this saves time while maintaining a high level of nutrient control.