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Cosmos Issues

My Cosmos this year are doing my head in. I always grow from seed and have never had issues before. In the front garden Flower buds form and seem to go 'crusty' and the foliage seems to get a red/pink tint. Growth is stunted (See first four pics). In the back garden, plants sown at the same time from the same seed packets, all are fine apart from one which has no buds at all but otherwise looks healthy (last pic). Any ideas what could be happening?

Gardening. The cause of, and solution to, all of my problems.


  • FireFire Posts: 17,319
    I guess it's an odd year. I am watering them a lot. Some large ones have bitten the clay. I would probably prune down the crispy bits and have a later flowering time.
  • fidgetbonesfidgetbones Posts: 17,233
    Looks like an infestation of some sort. Pick off the affected bits, prune it down a bit , water well and hope for cooler weather.
  • FifsFifs Posts: 45
    My cosmos are plagued with black fly so are not looking their best. It certainly is an odd year and a challenging one! 
  • Mine are also doing my head in.Fabulous four foot tall lush foliage but not a bud in sight!!
    The whole truth is an instrument that can only be played by an expert.
  • FireFire Posts: 17,319
    VG, they are probably growing in over-rich soil. You will probably just have autumn colour in your garden. That can be wonderful too.
  • stewyfizzstewyfizz Posts: 161
    Will try and prune out the worst bits. See what happens. OH wants to get rid but i don't want to give up that easily! Spent too much time nurturing them from babies!
    Gardening. The cause of, and solution to, all of my problems.
  • It could be down to a little green thrip or something similar. I've had to get rid of a few of mine for that reason and I've been growing Cosmos for years.
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