Ericaceous Compost

Both come as 8 litre carry bags at the same price, and both are formulated to the same low pH, carry added iron and are enriched with Gro Worm worm casts, so either will keep an acid-loving plant happy.

The difference is in the base. Our Ericaceous Black Gold Compost is the straightforward choice for potting up, repotting and topping off. The John Innes Ericaceous is made to the traditional loam-based John Innes recipe, which gives a heavier mix that holds its structure in a pot for longer, so it is the one to reach for when you are planting something that will sit in the same container for years, such as a camellia or a mature rhododendron.

Ours is enriched with pure worm casts. Worm casts improve the structure of the compost, help it hold moisture without becoming waterlogged, and make nutrients more readily available to the plant. Most ericaceous composts do not contain them.

We also add iron. Acid-loving plants suffer when they cannot access iron, and the added iron works alongside the low pH to keep foliage deep green rather than yellowing.

Yes to both, though for different reasons. Blueberries are the fussiest of the acid-lovers and genuinely will not crop well without acidic compost, so a pot of ericaceous is the most reliable way to grow them, particularly if your garden soil is on the alkaline side.

Hydrangeas are a choice rather than a necessity. They grow perfectly happily in ordinary compost, but pH controls their flower colour, so if you want blue flowers rather than pink, ericaceous compost is how you get them. You will need to keep the pH down year after year rather than doing it once.