3.5KG XXL All In One Mushroom Growing Kit - Maximum Yields | Serious Growers UK
3.5KG XXL All In One Mushroom Growing Kit - Maximum Yields | Serious Growers UK
- Maximum Yields | 800g-1.5kg total yield potential from professional-scale kit
- Serious Growers | 2KG grain + 1.5KG substrate for experienced cultivators
- Large Scale Growing | Requires proper fruiting chamber setup for experienced cultivators
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Maximum Yields for Serious Growers.
Our XXL 3.5KG kit is designed for experienced cultivators who want professional-scale yields at home. With 2KG of premium rye grain and 2KG of substrate, this kit delivers the largest harvests possible from a single container.
What's Included
- 2KG sterilised organic rye grain
- 1.5KG premium CVG substrate blend
- Nitrile gloves and surgical mask
- Alcohol and antimicrobial wipes
- Complete growing instructions
Professional Scale Results
1. Inoculate - Add 15-20ml of spores for optimal colonization
2. Colonize - 4-6 weeks for full grain colonization
3. Fruit - Expect multiple large flushes
4. Harvest - 800g-1.5kg total yield potential
Expected Results
- Total yield: 800g-1.5kg fresh mushrooms
- Timeline: 6-8 weeks from inoculation to harvest
- Flushes: 2-4 harvest cycles typical
- Container size: Requires large fruiting chamber
Perfect for Experienced Growers
This XXL kit is ideal for cultivators who understand the growing process and want to maximise their yields. The large size requires proper humidity control and larger fruiting containers, making it perfect for serious hobbyists and small-scale commercial operations.
Quality Guarantee
100-day money back guarantee. Our XXL kits undergo the same rigorous sterilization process as our smaller kits, ensuring contamination-free results for larger-scale cultivation.
Technical Specifications
- Grain: 2KG organic rye berries
- Substrate: 1.5KG CVG (coco coir, vermiculite & gypsum)
- Self-healing injection port: Yes
- Filter patch: 0.22μm sterile filter
- Plain packaging: Discrete delivery
- Instructions: Complete PDF guide included
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Easy Payment Options
Easy Payment Options
We accept all major credit and debit cards and cryptocurrency payments.
For cash or crypto on delivery, please email us first to arrange details before placing your order: support@williamscosupplies.com
All transactions are processed securely.
Fast & Discreet Delivery
Fast & Discreet Delivery
FREE delivery on orders over £30.
Your order will be sent with Royal Mail or Parcelforce, you will receive
an email once your order has been dispatched.
Orders are dispatched within 3
working days unless stated otherwise.
Plain packaging.
30 Day Grow Guarantee
30 Day Grow Guarantee
We offer a 30 Day Money Back / Replacement Guarantee on all of our products.
To claim your replacement or refund please send us photos of the issue to: support [at] williamscosupplies.com and we will do our best to help you.
Growing Guidelines
Growing Guidelines
Legal Disclaimer
All products sold by Williams Co Supplies are intended for lawful uses only. Our mushroom cultivation supplies are designed for growing gourmet and medicinal mushroom species.
We explicitly prohibit the use of our products for cultivating psilocybin-containing mushrooms or any other controlled substances. Cultivation of psilocybin mushrooms (magic mushrooms) is illegal in the United Kingdom and most other jurisdictions, with severe legal penalties for violation.
By purchasing our products, you acknowledge this disclaimer and confirm that you will use these items solely for legal mushroom cultivation purposes. Williams Co Supplies accepts no responsibility for misuse of our products contrary to applicable laws and regulations.
If you have questions regarding which mushroom species may be legally cultivated, please consult appropriate legal resources or authorities before proceeding.

