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Cosmos
Meomye
Posts: 949
Hi, I have planted lots of Cosmos seeds and some are beginning to bud but are very tall and leggy. Do I need to nip off the first few buds to encourage them to bush out?
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If you cut the top out , it will bush from lower down. Flowers will be a bit later, but you will get more overall.
Thanks for replies, so to clarify, do I nip the top bits off of all of the plants regardless as to whether they have a bud on? and if so how much should I nip off, because as you say, some of them are getting quite tall.
If you have lots of cosmos I would pinch back half of them very hard (down to about 6") immediately. They will flower very late but they should be bushier, sturdier plants. Meanwhile the other half will give you some earlier flowers - albeit on tall and leggy plants which might need to be supported. You can pull these out when the bushier plants are about to flower.
It is a bit late to be doing this now and there is a risk the pinched back plants won't flower at all if we have a cold summer or you live in a cold area.
I usually sow seeds at the beginning or April and pinch back regularly until the beginning of June. I have lots of other plants in flower through June & July but the later sowing and pinching back means the cosmos flower when I need them in August / late summer / autumn until the frosts.
I've made a note of all this for next year.
I bought some already leggy plants about a month ago and as I knew no better, I pinched the tips out. They have bushed out a little but I think I was a bit late. I'm glad to know it's possible to get later flowers. I thought I'd missed the boat.
Thanks TB and FB.
Welcome PP
I usually pinch mine back several times to keep them at about 6" until around mid June by which time there should be several sturdy stems. Then they are allowed to start doing their own thing. They nearly always make over 3' by the end of August and the latest I've picked flowers off them was in November! Getting a bit straggly by then but they are lovely plants in autumnal light.
If a plant particularly likes a situation it can easily become the size of a small shrub. I quite often end up cutting plants back again towards the end of August (not all over just some carefully selected stems) to keep them at a sensible size.
Important to keep on top of dead heading to keep the plants flowering until the frosts.