Do my perennials think its Spring?

Nollie

Most of my perennials like salvias, agastache, heleniums etc., bravely kept flowering through this summer’s extreme heatwaves here, but now its calmed down a bit, they have put out loads of new flowers on the old stems and are enjoying an Indian summer - its almost like the are making up for lost time, and some, like this Agastache Blue Boa (behind the red salvia) have reflowered in their true colour, having been a sickly pink in the heat:


But this is interesting, Some are dying right back, but at the same time producing lots of new basal growth and throwing up completely new flowering stems, like this Helenium Waltraut. Is this a common reaction to what is now a warm, pleasant September or have they got confused and think its Spring??...


Do you think I should give them a tomato feed in the hope of getting another flowering performance or would this just stress them out? Would that be cruelty to Heleniums?

Lyn

That’s normal for new growth to come up, I wouldn't feed now at this time of the year, they make soft growth that could get damaged by frosts, if you ever have frost where you live,  they will go into winter sleep soon, just let them rest.
I don’t ever feed perennials just a thick pile of homemade compost on top in the late autumn early winter. 

Nollie

Thanks @Lyn, I don’t usually feed any perennials either, just a mulch too. I do get frost (and occasional snow) but not normally until late winter. I was just being greedy expecting them to perform again, so I will take your advice, not feed and leave them alone.

Perki

Some helenium clumps increase in autumn and others in spring , thats why its advised to divide in spring because autumn divisions can fail . 

Nollie

Thanks for that @Perki, Waltraut must be an autumn increaser then! They didn’t do that last year hence thinking it may be weather-related, but they were new plants then, so probably too young to think about border takeovers.

Papi Jo

Not strictly a perennial, but can my chocolate vine /Akebia quinata 'Cream-flowered' compete?

Yesterday, as I walked under my pergola, I saw a creamy-white petal fall. I looked up and saw a small bunch of flowers, it was my Akebia quinata believing it was spring! This is the first time I've seen this, maybe after a severe pruning at the beginning of summer, to get a less dense shade? The perfume is still as delicious as ever.

edhelka

I had clematis montana reflowering this September (several blooms only). I prune it as needed because it grows too quickly. On the other hand, my group 2 clematis never reflowers no matter how i prune it.

Fairygirl

The Group 2 only needs tidying after the first flowering, so perhaps you're trimming a bit too much off  @edhelka
We don't tend to get much in the way of 2nd flushes. Shorter season - might be the same for you. We get one or two here and there - although last year there was a bit more due to it being hotter than normal here. 
The montanas usually do though. I no longer have any, but the ones in previous gardens always had a second lot of flowers. 

edhelka

@Fairygirl I haven't prune it at all last year (although I only bought the house in summer, so it's possible the previous owner did). Nothing. I pruned it lightly this year and again nothing. I think it isn't happy, I should probably water it and feed it more. But it still flowers well in spring.

I didn't know montanas can reflower. I thought they only flower on old wood.

Papi Jo

My Clematis 'Samaritan Jo' (group 2) is in full bloom, almost as many flowers & buds as in June. I follow the seller's advice scrupulously: prune down to about 50-60cm above the ground in February and again in July. Works very well.

Nollie

It seems the hot summer throughout Europe has had some influence on unusual flowering patterns - my wisteria has flowered three times but my Lagerstoemia is only just beginning to. Love your Akebia @Papi Jo, I was wondering if I could train one horizontally along a fence, espalier-style, or are they determined to grow vertically?