Dutch Pro Original Grow Soil A&B SW — Two-Part Vegetative Nutrients for Soft Water Soil Growers
Best for: Soil growers in soft water areas wanting complete micronutrient coverage during vegetative growth
Our thoughts
This is a proper two-part veg feed built specifically for soil, not borrowed from a hydro line. Dutch Pro have spent 30 years getting the formula right rather than the packaging, which is exactly where your money should go. If you're on soft water and want steady, clean growth without constantly second-guessing your feeding, this does the job reliably.
Dutch Pro Original Grow Soil A&B SW is a two-part liquid base nutrient designed exclusively for soil-based growing during the vegetative stage. Formulated for soft water areas (below 60 mg/l calcium and magnesium), it delivers a balanced blend of macro and micronutrients that compensates for low background minerals in soft water, supporting strong, healthy plant structure from seedling through to the pre-flowering transition.
The two-part system is the key here. By splitting nutrients across Part A and Part B, Dutch Pro can deliver more micronutrients than single-part feeds allow — preventing lockout and keeping everything bioavailable when your plants need it most. For soil growers who've been using generic one-part feeds, this is a noticeable step up.
How it compares
Dutch Pro sits in the professional-grade but accessible tier of vegetative soil nutrients.
- Two-part system vs. single-part (more micronutrients, better precision)
- Soft water-specific formulation vs. universal blends (prevents early deficiencies)
- Soil-designed, not adapted from hydro ranges (appropriate nutrient balance for soil chemistry)
- Comparable to House & Garden Soil A&B in quality; better value than premium single-part alternatives
If you're comparing to Canna Terra or General Hydroponics, you're trading convenience (single-part) for completeness (two-part micronutrient profile) and water-type intelligence (soft water optimisation).
Usage guidance
Mixing protocol
Fill your container with water, add Part A, mix thoroughly until dissolved, then add Part B and mix again. Never combine the neat concentrates — this prevents nutrient precipitation and lockout.
Dosage
Dutch Pro recommend 2–3 ml per litre of both Part A and Part B. Use a syringe or measuring beaker for accuracy. Check your mix with an EC/PPM meter (Bluelab Truncheon is the standard) to confirm strength.
pH management
Aim for a pH range of 5.8–6.5 for optimal nutrient uptake. Dutch Pro produce a dedicated pH Down (Grow) based on nitric acid, which works better during the vegetative stage than phosphoric acid alternatives.
Application method
Works equally well hand-watered or through irrigation systems. Soil responds best to consistent, moderate feeding — avoid overloading. Let soil dry slightly between waterings to maintain healthy root function.
Feeding window
Use throughout the entire vegetative stage, from seedling establishment through to the point where you switch to a flowering nutrient. Don't extend into flowering — this is growth-phase only.
Technical specifications
- System Type: Two-part liquid mineral concentrate (Part A + Part B)
- Formulation: Soft Water (SW) — optimised for water sources below 60 mg/l calcium and magnesium
- NPK Ratio: 4-2-6 (approximate; soft water variant may vary slightly)
- Nutrient Profile: Complete macro and micronutrient blend
- Recommended Dosage: 2–3 ml/litre Part A + 2–3 ml/litre Part B
- Optimal pH Range: 5.8–6.5
- Application: Hand watering or irrigation systems
- Available Sizes: 1L, 5L, 10L, 20L bottles
- Mixing Requirement: Parts must be added separately to water; never mix concentrates neat
Who this is for
- Soil growers in soft water areas (Scotland, southwest England, Wales, and other low-mineral regions)
- Growers stepping up from single-part feeds who want more complete micronutrient coverage
- Those after professional-grade results without the professional-grade price tag
- Vegetative-stage specialists who want a feed designed for soil chemistry, not borrowed from hydro ranges
- Growers who value consistency and soil structure over aggressive feeding schedules
- Anyone running multiple plants or rooms where feeding stability matters more than constant adjustment
Our take
This is a solid choice if you're on soft water and serious about soil growing. Dutch Pro have spent decades getting the formula right, and you can feel that in how it performs — steady, clean, forgiving growth without the salt buildup that can wreck soil structure.
The two-part system adds a mixing step, but that's actually the point. You get better micronutrient coverage and better control than single-part feeds offer. Pair it with Dutch Pro's pH Down (Grow) and additives like Take Root or Multi Total if you want to dial things in further.
Good time to pick this up while stock lasts. Does exactly what a vegetative soil nutrient should do, day in, day out.
