"they can be hard to remove as they spread via tubers"

... and seeds... :(

that's why I haven't planted the pink ones in some pots, as pretty as they are... I'm afraid that I'll still end up with them everywhere due to the seeds...

Carol in Jacksonville

Here is a link that might be useful: Prior thread on four o'clocks

This post was edited by love_the_yard on Tue, Mar 4, 14 at 15:29

Just for fun, I went to Google Images to see how big the tubers can get. And there was an image Kara posted back in 2009! Big ol' thing.... yikes! (Like that croc that the Aussie snake ate if ya saw that set of pics this week.)

Carol in Jacksonville

Here is a link that might be useful: Kara's four o'clock tuber that ate Chicago

This post was edited by love_the_yard on Tue, Mar 4, 14 at 18:13

Python Eats Crocodile By Swallowing It Whole (PHOTOS)

Here is a link that might be useful: Python Eats Crocodile By Swallowing It Whole (PHOTOS)

Hmm... so it looks like I will be using the sunken pot method after all. And spot check for seedlings, or deadhead. Not to mention these will be one of the few I will have to pull up when we move as I wouldn't want to pass along problem plants to the next resident. Most of my plants are well behaved enough that they should be able go untended for the most part and won't become an issue. These Four O'Clocks and my Porterweed are notable exceptions.

Planted Four o'clocks 4 years ago from a "gift" at the Garden Club. Pulled plants after first year. Have been pulling seedlings for 3 years now. They just won't stop.
Bob in Jacksonville

That monster tuber was not the norm, particularly the tap root. As long as your not planting among tree roots the tuber isn't really a problem. The only way a tuber will produce more plants is if you accidently chop it up with a tiller. Then all the little pieces of tuber will start to grow. The real way that 4 o'clocks spread is by seed and as long as you pull the seedling up before they have a chance to form a tuber your fine. A healthy 4 o'clock is a prolific seeder. The worst is when a tuber grows around tree roots. You'll never get rid of it then!

Biggest tuber I've dug up was maybe 10"-11" long & 3"-4" wide. Seedlings are easy to hoe/pull if you get 'em early.