[Sue32]

lots of my herbaceous plants  need support and tend to floppy, eg sedum, rudbeckia and a hardy geranium are twice the advertised height etc
but I've noticed other gardeners don't have as big a problem.   How do I stiffen them up a bit (don't mind if they're a bit smaller)

I suspect I'm being too kind to them - lots of well rotted horse manure each year (autumn or spring depends on weather). 
The soil is in good condition now but leaches nutrients.  If my suspicions are right what should I use instead?

[mumofstig]

Why not try without the manure, there is probably more than enough goodness in the soil by the sound of things 
Flowers in general are not such gross feeders as veg IMO
My soil is quite poor and dry, but I still grow sedums and hardy geraniums with no problems.
My shasta daisies do get staked, a few twiggy prunings pushed in does the job

[Goosegirl]

A few canes joined with attached twine pushed in early on in the season helps as the plants' leaves grow out to hide them. I live in a very windy situation so I know the flop problem! Although I haven't done this yet but will do next year, you could always try the "Chelsea Chop" where they cut back perennials so they branch out better (I think) but they will flower later. Google this to check.

[Sue32]

thanks, maybe save me all the work of bagging it up etc ......

yes I've heard of the Chelsea chop - tried it on half a sedum (not very brave about it, to see the effect) and it did seem to help but
A) not sure exactly which others to apply to and
B) missed the date this year and didn't want to do it too late and get nothing at all to flower!
Same problem with the staking - I always seem to be too late.  Must try harder next year!
Main problem though was things like geranium Rozanne at over 3ft tall.     It didn't just flop it outgrew everything around it!  so I think I have to be mean to them.

Thanks again both

[Jews32]

Perhaps because of the cool wet May we had many of my perennials are huge this year-I have Blue Fortune Agastache which is more than 6 feet tall! The bees are loving it, so I'm just going to try to stake it, but what happens if I cut back Nepeta now? And what can I do with Coreopsis Moonbeam which is looking black and crispy in the center?
Is it better to just let things sort of flop and look sloppy, or try to reign them in? (Sort of a philosophical question, I know....)

[robbodaveuk]

Have you thought about a crushed viagra tablet in their feed .

 Robbo.

[sunshineband]

Perhaps because of the cool wet May we had many of my perennials are huge this year-I have Blue Fortune Agastache which is more than 6 feet tall! The bees are loving it, so I'm just going to try to stake it, but what happens if I cut back Nepeta now? And what can I do with Coreopsis Moonbeam which is looking black and crispy in the center?
Is it better to just let things sort of flop and look sloppy, or try to reign them in? (Sort of a philosophical question, I know....)

Hi Jews32
Would you mind popping into to the Welcome section and introduce yourself,as then memebrs can may be give their advice appropraite to where you live?
 

[JayG]

Main problem though was things like geranium Rozanne at over 3ft tall. It didn't just flop it outgrew everything around it!  so I think I have to be mean to them.

I have a Rozanne growing in poor sandy soil and if it's lucky it gets a handful of Growmore in spring. That's enough to get it to spread at least a metre in all directions, but it doesn't reach more than about a foot high so it's manageable (and a great flowerer!)

"Mean" is probably the best way to limit its bid for world domination!