[seanandde]

I've very limited experience of growing anything from seed but this year have tried lots of annuals to fill in the gaps in borders cheaply.  They're mostly different varieties of Cosmos.

Everything got pricked out into 3" either peat or plastic pots to grow on about 3/4 weeks ago.  They've been in my greenhouse overnight and sat on the garden table in the sun during the day and it's been very warm here in the s/e... but they seem to have stalled, growth wise.  They're mostly about 2.5" tall with one two sets of true leaves.  There's been a small amount of growth but not what I expected.

Am I just being impatient?  Do plants this young need feeding? They were all transplanted into fresh compost.  I know I've probably fussed a bit over what could have been started a bit later and sown directly into the gound but I have a bit of an ongoing battle trying to keep weeds in my borders under control thanks to arthritis and not being able to kneel/bend much at all... just wanted to get something to a reasonable size before OH plants them out for me, which seems to have backfired!

Would appreciate some advice - thank you

[JayG]

Cosmos are half-hardy annuals so can't be planted out until the risk of frost is over.

They are pretty strong growers (and a big favourite of mine!) but they will certainly be struggling in 3" pots after all this time, especially as the nutrients in the compost will be exhausted by now.

At least feed them, preferably re-pot them, and next year perhaps consider sowing them directly outside in small groups (makes it easier to stake them because they can get quite tall.)

[seanandde]

I too love Cosmos, witnessed by the 120'odd in their (too little, I now discover) pots all over the place.

I had no idea that such tiny little things should be in larger pots by this stage having only been transplanted 3.5 weeks ago.  Having just carefully tipped one or two out they're definitely not pot bound; the opposite, I'd say, with a few visible roots but nothing like you'd expect to see.

I'll give them a feed and re-pot them at the w/e.  At this rate I'm beginning to wonder how much I've saved myself on not buying them as small plants from the garden centre... right, off out for more compost and more pots!

[JayG]

120 !!!!    

I wouldn't be repotting that number until they were definitely pot-bound; try the liquid feed to gee them up a bit - you may get away with it, depending on the frost situation where you live (no location in your profile!)

[seanandde]

I know, it's ridiculous   I didn't expect them to germinate so well and then thought I'd have a proportion of fatalities when I pricked out the seedlings which I'm usually none too good at.   I'll be mortified if they don't grow.  They all look really healthy... but just aren't "doing" anything.  Thank you, I'll definitely feed them.  Oh, we're right in the south east corner and I can't remember the last time I had to water flagging perennials in April !

[Goosegirl]

I wonder if it is due to the fluctuating day and night temperatures..? They aren't pot bound and I would be surprised if they were after such a short time. The feed won't harm as their root system doesn't sound as it should be. Perhaps the compost wasn't particularly good either..?

[seanandde]

Easy for me to come back and say I wondered that too   But I did, on both counts.  Days have been extremely warm, nights fairly chilly though no frost and, though they all were transplanted into compost which was newly opened, must admit it's very cheap stuff in a big bale from the DIY store.  Might have been a false economy.

The good news is, they've definitely put on a (small) spurt after feeding and probably milder nights over the last 2//3 days has helped.