Sedums on trial

From 2004 to 2006 the Royal Horticultural Society ran a trial of sedums at its garden at Wisley in Surrey. It was fascinating. The report of the trial has just been posted on the RHS website.

The trial was limited to the sedums of the herbaceous border; alpines and woody sedums demand different conditions. Those on trial were Sedum spectabile, S. telephium and their close relations: those which, I’m afraid, may well eventually end up in a completely separate genus – Hylotelephium. We’ll get to that issue another time – or maybe not…

Over eighty entries were grown, sent by nurseries and gardens both in the UK and USA. They were assessed over three years; I and the other judges paid special attention to: foliage, habit, flower quality, length and season of flowering, overall character, and attractiveness to bees and butterflies. 

Ten outstanding entries were given the Award of Garden Merit.  These are the award winners:

Sedum ‘Bertram Anderson’
Sedum cauticola ‘Lidakense’
Sedum ‘Herbstfreude’ (Autumn Joy)
Sedum ‘Mr Goodbud’
Sedum ‘Ruby Glow’
Sedum spectabile
Sedum telephium ‘Marchants Best Red’
Sedum telephium ‘Purple Emperor’
Sedum telephium ‘Red Cauli’
Sedum ‘Vera Jameson’

Growing a trial like this always turns up some interesting surprises and this was no exception.

• Reversion Many of the cultivars of Sedum spectabile, especially the white flowered forms, have a tendency to revert to pink (and then, perhaps, back again) which can cause untold confusion.
• Chelsea chop One of the three plants of each entry that were grown was cut back in May to create a bushier plant that did not need staking. This generally worked very well; in some cultivars this delayed flowering, in some not. It’s well worth trying, especially on rich soil when many of these sedums tend to fall over without support.
• Graham Gough Three of the ten award winners were raised relatively recently by that fine plantsman Graham Gough of Marchant’s Hardy Plants. These were ‘Marchants Best Red’, ‘Purple Emperor’, ‘Red Cauli’. He has more on the way…

Sedums are super plants for late summer and fall, I’d suggest that you start with these award winners.

You can download the full trial report, free, from here.

Comments

[Kim]

Graham, I had trouble with the link to the report... I was able to discern which part to pull out of the link to get there, but thought you might want to know. In the meantime, if you're reading this and want to find the page, past this into your browser:
http://www.rhs.org.uk/plants/documents/sedum2006.pdf

[Kim]

Also... thank you as always for posting such good information. :)

[Graham Rice]

Thanks Kim, I appreciate your remarks. The pdf download seems to work fine in some browsers and not in others. I've asked the good people at our hosts, TypePad, for advice on this.

[Kim]

Ah. If it helps the tech troubleshooters, I'm visiting you courtesy of Mozilla Firefox v. 1.0.1. (I probably need to upgrade--it may be my fault.)

[Graham Rice]

Kim, It's your browser settings, I'm afraid. Apart from upgrading (my Firefox is 2.0.0.3), take a look at this page from the Adobe website: http://tinyurl.com/29uplt

[lisa]

Thanks for the info, especially regarding reversion...I've been wanting a white-flowering variety, now I'm not sure. Is there anything to be done to prevent this? I already have several sedum cultivars...I presume they might contribute to this problem.

[Graham Rice]

If you plant a white one, Lisa, and it stays white - fine. If it starts to revert, mark the reverted shoots and then discard that section of the plant, or re-plant it elsewhere, and propagate from the parts that stayed white.