Cosmos Mildew

[LexLucre]

Any advice for mildew on Cosmos? Just noticed it's hit all the plants that are currently providing lovely colour infront of my living room window. The foliage has a light grey powdery coating, so I assume that's what it is.

All my cosmos died very early last year and looks like it'll be the same again this year, such a shame. The spot they're in is west facing and gets very intense afternoon sun but nothing in the morning (southeast of the country). Maybe it's as simple as that and it's just not a spot I can grow cosmos in. Still, they've been so strong until now and there have been a really impressive number of blooms, they can't have been that unhappy.

A Google search gives old book suggestions of various fungicides that work, but a cursory search doesn't suggest they're available anymore, probably harmful and outlawed long ago.

I'll just have to give up growing them. I have a similar problem with courgette which gets mildew early every year despite fullish sun and keeping ontop of the watering, spraying with milk or other leaf invigorators. Maybe it's just something to do with the climate here in London.

[Babru]

What a shame! Cosmos are one of my favourite flowers, such a long season and such a beautiful show. Perhaps try planting them further apart? They say that allowing air around the plant discourages mildew.

My trouble is, every year I can't imagine the size the plants grow, so end up putting them too close together and having to shift some. Haven't had a mildew problem (yet!), but I'm next to the sea and Edinburgh's pretty windy, which may help.