Best Potassium Based Fertilisers Deals Online in the UK (25 Deals Found)

Last Updated - 15/12/2025 Sort By:

Best Choice
Elixir Gardens

New
Elixir Gardens UK High Potassium Liquid Fertiliser/Plant & Lawn Food | N.P.K 6-6-12 | Various Sizes 500ml-5L | 1 Litre M
High Potassium Liquid feed for use all through the growing season

£8.49
Best Value
Elixir Gardens

New
Elixir Gardens UK High Potassium Liquid Fertiliser/Plant & Lawn Food | N.P.K 6-6-12 | Various Sizes 500ml-5L | 5L Makes
High Potassium Liquid feed for use all through the growing season

£15.99
New
High Potassium Liquid Fertiliser 500ml-10L | NPK 6-6-12 | 1L treats up to 250sqm
High Potassium Liquid Fertiliser 6-6-12 | 1 Litre treats up to 250m². Elixir Gardens High Potassium Liquid Fertiliser 6-

£17.99
SuperGift.com

New
1kg, Organic Potato Fertiliser, Natural Plant-Based Formula for Stronger Roots & Higher Yields, Rich in Potassium, Ideal
ORGANIC FORMULA: Natural plant-based fertiliser specially formulated for potatoes and root vegetables, promoting stronge

£8.99
New
Mono Potassium Phosphate Fertiliser Hydroponics Feed Aquarium Fungicide FREE P&P
Soluble salt which isused as a fertilizer and a fungicide. It is a source of phosphorus and potassium. It is also a buff

£7.97
Greenleaf Nutrients

New
Seaweed and Kelp Fertilizer for Plants - Organic Sea-K - Concentrated Extract Powder Nutrient Makes 700 Liters
【Kelp seaweed extract】has long been known as one of the most effective, natural and potent ways to improve your plants.

£9.36
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Neudorff

New
Neudorff Organic Tomato Feed – Organic liquid fertiliser for all varieties of tomatoes. Rich in Potassium for full-flavo
For all varieties of tomatoes: Special fertiliser for all varieties of tomatoes in tubs, beds or raised beds

£11.53
Free Shipping
New
NPK 16-5-25 + 3.4Mg Water Soluble Premium Fertiliser Nitrogen Potassium Topping
NPK 16-5-25+Mg Water-Soluble Premium Fertilizer – Nitrogen-Potassium Top Dressing. Boost your plant’s health and product

£2.25
TOP SAVER

New
Clematis Fertiliser 0.9kg - Organic-Based Feed for Vigorous Growth & Prolific Flowering of Clematis, Honeysuckle, Passio
Organic-Based Formula: Made with natural ingredients, this fertiliser provides a balanced, environmentally-friendly opti

£10.99
New
Organic PK Fertiliser. 5% Phosphorous, 5% Potassium & 15% Calcium
Dr Forest’s PK Fertiliser is a premium blend of natural minerals, expertly crafted to enrich soil with a balanced array

£9.50
Elixir Gardens

New
Elixir Gardens BioPlant Vegan Animal Free Fertiliser Pellets | Organic, Sustainable & Eco-Friendly Plant-Based Soil Enha
Slow-release plant-based fertiliser pellets. High mineral content, perfect for boosting plant nutrition.

£10.99
Elixir Gardens

New
Elixir Garden High Potassium Fruit & Flower Fertiliser/Feed | Concentrated 10 Litre Bottle
High Potassium Liquid feed for use all through the growing season.

£19.99
New
Elixir Gardens High Potassium Soluble Fertiliser | High Potash | NPK 15-5-30
High Potassium Soluble Fertiliser | High Potash | NPK 15:5:30. Bumper Crop High Potassium Fertiliser | N.P.K: 15-5-30. B

£74.99
Elixir Gardens

New
Elixir Gardens Fish, Blood and Bone Meal | Organic-Based Fertiliser | 10kg Bucket | Treats over 140sqm
STIMULATE YOUR LAWN – Fish, Blood & Bone replenishes lost nutrients, invigorating grass growth for a lusher, healthier l

£18.29
New
Concentrated Liquid Fertilisers | Make up to 2000L of Ready-to-Use Plant Feed
Elixir Concentrated Liquid Fertilisers | Available from 500ml - 10L | Makes Up to 2000sqm coverage. Faster plant uptake

£9.99
Elixir Gardens

New
Elixir Gardens Soluble Sulphate of Potash (S.O.P) Fertiliser | Potassium Sulphate Plant Feed | 1kg Tub
Amazing Value! 1kg can treat up to 70sqm of land.

£11.99
New
Elixir Gardens Bumper Crop High Potassium Fertiliser - NPK: 15-5-30 | 700g-20kg
If you are in an area with acute hard water, Soluble NPK fertilisers can dry on the leaves and leave unsightly residues.

£74.99
New
General Purpose Compound Base Fertiliser | NPK 5-7.5-10 | Bags & Tubs 500g-25kg
Traditional general purpose fertiliser for fruit, vegetables and flowers. General Purpose Base Fertiliser. For roses, mi

£59.99
New
5kg 13-0-46 POTASSIUM NITROGEN WATER SOLUBLE FERTILISER, HYDROPONICS
5kg POTASSIUM & NITROGEN FERTILISER HIGH PURITY. FULLY WATER SOLUBLE.

£44.95
New
High Potassium Liquid Fruit & Flower Fertiliser/Feed | NPK 6-6-12 | 10 Litre
10 Litre High Potassium Liquid Fertiliser Bottle | N.P.K 6-6-12. High Potassium Liquid Fertiliser Bulk Buy 10L | N.P.K 6

£17.99
New
25kg 13-0-46 POTASSIUM NITROGEN WATER SOLUBLE FERTILISER HYDROPONICS
25kg POTASSIUM & NITROGEN FERTILISER HIGH PURITY. FULLY WATER SOLUBLE.

£109.95
New
2.5kg 12-0-46 POTASSIUM NITROGEN SOLUBLE PLANT FOOD / FERTILISER
2500grm POTASSIUM NITROGEN FERTILISER. FULLY WATER SOLUBLE.

£22.95
New
Nutrigrow Low Nitrogen Soluble Fertiliser 25kg Fruit Flowers High Potassium
Nutrigrow (7.5-12-36+4.5Mg+10SO³) Low Nitrogen Soluble Fertiliser 25kg. Low N is a water soluble NPK fertiliser which ca

£74.99
New
Lawn Fertiliser Granules 20kg Spring Summer Nitrogen Phosphorus Potassium
Why Choose Our Ultimate Lawn Fertiliser?. With its ingredients and specific formulation designed for the UK climate, thi

£115.85
New
Ecoworm Organic Fruit & Vegetable Feed – High Potassium Liquid Fertiliser 1L
Ecoworm Organic Fruit & Vegetable Feed – Liquid Fertiliser & Soil Improver (1L = 200L). Unlike chemical fertilisers, Eco

£13.99

25 Potassium Based Fertilisers deals are available from: Amazon, eBay stores, starting from £2.25.
The biggest discount we found is 10%% on Elixir Gardens UK High Potassium Liquid Fertiliser/Plant & Lawn Food | N.P.K 6-6-12 | Various Sizes 500ml-5L | 1 Litre Makes up to 250L of liquid feed | 1 Litre Bottle at Amazon.
The lowest price we found is £2.25 while the highest is £115.85.
Prices for the best Potassium Based Fertilisers deals average at £31.40.
Last updated on December 15, 2025.
We scanned these quality online stores and more to deliver you with the best offers online available for Potassium Based Fertilisers.