I don't really understand what this is . So my Rudbeckia Goldsturm - if I want later, more, smaller flowers then I chop it back by half? Is this what the Chelsea Chop is?
Yeah, that's the plan. Dont ask me what plants it works with though. I would think there must be some that dont respond well to it, and it is getting a bit late now.
Normally done mid May the idea being to encourage flowering at the back end of the summer. I have done it in the past with a few things including the large Sedums, now called Hylotelephium). Yes it worked as they can get quite leggy and are also brittle so making them a bit shorter did help. Problem I have is I think about it get busy with other stuff and don't remember in time.
I am not sure what else benefits from the chop, I left my Sedums and now are very tall. It is supposed to be done Chelsea Flower Show time, ie near the end of May. Might be too late to cut mine back now, may try next year, if I remember!!
A bit late now but you can do it for many herbaceous perennials. The idea is to either prolong the flowering season or to produce more but smaller flowers - or both. If it's a large clump you can cut back part of it (usually at the front so you can see the shorter, smaller more numerous flowers). If you have smaller clumps but many of them you can cut back some clumps and leave others. You can Google which ones it works for but there are a lot of them.
I'm reviving this old thread to ask if anyone has tried a "chelsea chop" on plants which flower earlier in the year? I'm thinking about my Hesperis matronalis, which gets to about 1.5 metres tall (mild and wet around here!) and is very prone to falling over. When I cut down the spent flowers, I often get some shorter flowering stems later in the year, which makes me think it might work... obviously not in May though. My wallflowers always flop, too, no matter how well I chop them back when I plant them out. I'm quite tempted to try with them, too. Next May I'm definitely going to chop a lot of the Daucus carota in our "meadow" which insists on growing too close to the path. I love it, but it also revels in the damp soil and gets taller than me. And I know it'll come back and flower, because it's seeded itself into the lawn, where it flowers happily at 5cm. Does anyone have any favourites for the "chop"? I'd like to get planning, and the herbaceous border needs a re-design. (I'd never intended to have one - shrubs and mixed borders are more my line - but honey fungus made it the best option.)
What's your soil like @Liriodendron? I've found that if it is too rich, some perennials get a bit ambitious, becoming tall and leafy and falling over. I've used the chop on Heleniums which worked well and also on a Viticella Clematis, due to the arch collapsing, resulting in more flowers than ever before.
Thanks, @Plantminded - it's a heavyish, mostly alkaline loam. I've never fed anything growing in the ground, in the 5 years we've been here, so I'm pretty sure the main problem is the climate. It's rarely very dry, very hot or very cold. I think I'm just going to have to experiment with early chopping of late Spring flowerers.
You could try the usual chop on some @Liriodendron and a partial chop on others (cutting some of the stems to different heights) and see which works best for each plant. The RHS says that the chop also works for some early flowerers but doesn’t name them, which is helpful! There’s also a technique called the Hampton Hack, cutting perennials later, after they’ve flowered, to the base to encourage repeat flowering. It’s often used on hardy geraniums and I’ve found it also works with Nepetas. As you say, experimentation is needed though as some perennials my resent either or both techniques .