As novice gardeners we had been growing some box plants on in pots to plant out in a year or two when the garden plans were ready. However last year ( late summer) they all went gradually practically orange. I took this to be lack of watering so watered them like crazy. No effect. Was I now over-watering? So I finally actually bothered to look it up, turns out I was flushing out the nutrients box really needed. So I bought some of this in a smaller size. It was no miracle instant cure, in fact I'd forgotten about the whole problem until months later. One year on they are bright green and very very vigorous. Absolute result. This year we are ahead of the game and bought this 5kg tub as the economy over the small pack is excellent. You don't need loads, about a teaspoon per plant, but we have room to store so worth a bulk buy. Highly recommend but be patient. By the way our delivery came next day despite not being a Prime product so hats off to supplier.