What else can I do to keep black spot off my roses organically?

Feeding is the lever most people miss. Black spot loves soft, sappy growth, and high-nitrogen fertiliser produces exactly that. Go balanced, with extra potash in spring and again after the first flush. Tougher leaves mean less to infect. Then look at what sits against the base. Fine compost or grass clippings turn every shower into a splash zone flinging spores onto the lowest leaves. Chunky bark or gravel does the opposite. Water early. Base watering is right, but mornings mean any leaf that does get wet dries before dark. Be honest about your worst bush, too. In Harvey's wet winters some cultivars will always struggle. If one plant gets stripped bare every year while its neighbours are fine, that's the plant, not your routine. Replace it with a resistant variety and you've fixed something no spray can. Wipe your secateurs between bushes as well.

Sunlight is your strongest natural ally against fungal spores, so consider the placement of your garden beds. If surrounding shrubs or fences cast heavy shade, selective pruning of the wider landscape lets morning sun dry the dew off your leaves before the fungus can take hold. When the soil warms and drains efficiently, the plant's natural resistance improves. You might also try a light dusting of agricultural sulfur early in the season as a preventative barrier on the foliage, applied on a calm evening when the wind is low so it settles evenly across the leaves.

The two things that will do the most for you in Harvey's wet winters are air and fallen leaves. Black spot overwinters in leaf litter, so raking and binning every fallen leaf from under each bush — not composting it — does more than any spray. Open the centre of the plant with a hard winter prune; still air is where the fungus settles. Then milk: one part full-cream to nine parts water, sprayed on a dry morning, weekly. It holds its own against most conventional options and is genuinely organic. Sulphur or potassium bicarbonate are the other gentle standbys — rotate them so nothing adapts. Feed for strength rather than speed. Seaweed and compost, not heavy nitrogen, which pushes the soft growth black spot loves. And mulch, so rain can't splash spores up onto the lower leaves. Your base watering is already half the battle.