Chempak® High Potash Feed - Formula 4

Where to use:
Chempak Formula 4 is a balanced plant food with a high potash content, perfect for boosting fruit and flowers, giving it an all round summer use on borders and vegetable plots.

Use on: bedding plants, peppers, soft fruit, perennials, potatoes, tomatoes, houseplants, fuchsias, ornamental trees, root vegetables, flowers and hanging baskets.

How & when to use:

Normal Strength Use: Dissolve 2 level measures of crystals in 5 litres (approx.1 gallon) of water and apply to your plants every 7 to 10 days. Ensure the soil or compost is well moistened.

For more frequent use: Some gardeners prefer to use dilute feed more often. Dissolve 1 level measure in 10 litres of water and apply at every watering. At this strength this pack will make over 2,000 litres of plant food.

Professional tips:

Tomatoes: Feed weekly from early stages. Increase frequency to twice a week when fruiting to improve quality and yield.

Hanging Basket & Container Plants: The perfect summer feed for begonias, fuchsias, geraniums, and pelargoniums, etc. Use at bud stage and continue through the flowering period to ensure a succession of blooms.


Free Measuring Spoon & Feeding Guide included with every pack.

Seeds and garden supplies will normally be delivered within the time period stated against each product as detailed above. Plants, bulbs, corms, tubers, shrubs, trees, potatoes, etc. are delivered at the appropriate time for planting or potting on. Delivery times will be stated on the product page above, or in your order acknowledgement page and email.

Orders for packets of seed incur a delivery charge of £2.99.

Orders which include any other products will incur a delivery charge of £6.99.

Where an order includes both packets of seeds and other products, a maximum delivery charge of £7.99 will apply - regardless of the number of items ordered.

Large items may incur a higher delivery charge - this will be displayed in your shopping basket.

Please see our Delivery page for further details, and more information on different charges that may apply to certain destinations.

For more information on how we send your plants please visit our Helpful Guide on plant sizes.