Cutting the old plants down won't prevent spread, they're enthusiastic little buggers :) and they spread by underground runners. I found it pretty easy to get rid of any that came up where I didn't want them. The only reason I know for cutting them down is to get rid of the dying foliage and maybe any seeds. I used to sometimes cut them down in the fall and sometimes in early spring; can't say I noticed any difference but someone may know something I don't.

Happy gardening!

Do you want to look at all that dead stuff all winter? Then cut it down....if you don't mind, wait until spring.
Linda C

I really don't think you have to worry about mistreating the Dis-Obedient plant. The only worry is controlling it. I have been trying to get rid of it for three years. It keeps comming up. I wish I would have listened to the warnings from the local garden club.

Yes it is a matter of personal esthetics. I prefer to cut down as much down stuff down as I can in the fall. It frees me up in the spring, which is the busiest time in my garden.

I have to disagree with people not wanting to look at remnants of plants in winter (although I respect their choice). There are two reasons I like keeping dead plant material as long as it keeps hanging on.

I actually do like looking at dead plant material if it is still where it is supposed to be--it reminds me of what it all looked like in summer and what it will look like again come spring. To me, there is nothing worse than a winter garden that contains only snow and the occasional evergreen shrub. I like the textures and colours, as dull they may be compared to the summer landscape. Needless to say, I do pick up and throw out anything that has fallen off the plant and would only harbor pests and any accumulation of leaves that just looks dirty (but I let maple leaves accumulate in my borders to help insulate the soil and roots against sudden temperature variations). But I always let the plant choose the moment it gets rid of its parts.

The other, more important reason is that nature intended for those dead plant parts to hang on. Dull plant parts protect other plants and wildlife from wind and sun. They provide places for birds to hang out, and those same birds, if they stay long enough, will take care of some of your pests in spring. Not to mention that whenever something loose falls off, it eventually decomposes and nourishes your soil.

I think many gardeners today overpamper their gardens. Most of a garden's needs are taken care of by nature itself. Not only does this reduce the amount of work the gardener has to put in, but it is actually healthier for the garden. This is also why I let most of my plants move around without putting them back where I intended them to be--if the plant wants to go elsewhere, it is because it is seeking out better conditions. By leaving it alone, you allow it to grow stronger and healthier. If you force it back into that precise spot where you planted it, it will never achieve its full potential.

Back to the main topic. There is no point really in cutting back an obedient plant. Cutting it back does not affect growth, habit, etc. Whether you cut it back or not, it will grow back the same in spring. The only reason people do it is to remove dull stuff, for purely esthetic reasons. Doing so doesn't prevent reseeding as the seeds are dropped by the plant as soon as they are ripe. If you want to prevent reseeding, you're much better off deadheading spent flowers individually.

I do cut back my obedient plants, but not for the same reason as most people do. I simply do it because the stiff stems stand in the way of proper winter mulching. I also cut back my tansy for the same reason and remove hosta leaves as they are toxic to some other plants (never compost hosta leaves), but I leave all my other plants alone. As winter advances, it is fun to see the dry stems peek out from under the snow cover when it melts and disappear again after heavy snowfall.

How long does it take for the seeds to be ripe after flowering? I am wanting mine to spread! It didn't spread this year like I was hoping

Obedient plants spread by seeds. The tall stalks left over can easily be pulled from the ground the following spring as the new growth starts popping up. Many insects use ‘dead’ plants to overwinter and some insects live in the stalks of old plants. Thus, it is best to not start cleanup until the spring when it gets warm. I started with one plant, now ten years later I have five hundred. I want to experiment this year and am mowing some to keep them only four inches tall until they send up flower shoots, if they do. They might not put out flowers if I cut them back; it is an experiment.