← Organic fertiliser FAQ

What is the best organic fertiliser for roses and flowers?

Enough nitrogen to build strong stems, plenty of potassium for the flowers, and calcium and magnesium alongside. A balance around 5-3-5 covers it, fed in early spring and again after the first flush.

What a rose actually needs

Roses are hungry, and they are hungry for more than nitrogen. Nitrogen builds the canes and the foliage that will support flowering. Potassium does the work in the flowers themselves, in colour, in substance and in the plant's water regulation through a dry spell. Magnesium matters more than people expect, because it sits at the centre of the chlorophyll molecule and a shortage reads as yellowing between the veins of the older leaves.

A balance around 5-3-5 gives the nitrogen and the potassium without pushing phosphorus, which most established borders already hold in quantity.

When to feed

Mulch does half the work

A layer of well-rotted compost or manure around the base in early spring holds soil moisture, suppresses weeds and feeds the soil as it breaks down. Roses respond to it strongly, and it is the single cheapest improvement most rose beds can have. Keep it off the stems themselves.

For flowering plants that are not roses

Much the same logic applies to dahlias, sweet peas, perennials and container displays: enough nitrogen early to build the plant, then potassium as the flowers come. Bedding in pots runs out fastest of all and needs topping up every two to four weeks through summer.