I'm not familiar with this plant, but 99% of plants you want to redirect roots of potted plants. Get them to stop swirling. So yes, you probably want to remove dirt, and some damage is OK. With plants from pots to the ground you are supposed to run a knife along the sides and score an X on the bottom.

You can minimize damage by washing the dirt away with water.

Have no fear, you won't hurt your plant. Here's some pics to inspire you. Yes, removing the old soil is good. You can do it as drastically as I did in the pics, or be a little more conservative your first run at it. The basic thing about getting rid of any circling roots at the bottom advised above is good, especially if you find a solid pancake of them like I did. Once you do that, the rest of the soil should 'fall out' a lot easier, and you can get your fingers to the inner parts more easily. Try to pick a day when it's above 60 outside, shouldn't be too uncommon where you are at this time of year. I'd still try to do it in the shade if possible.

purpleinopp:

thanks for your advise. Somehow images on your blog were having a very difficult time loading, since I don't have problem with other websites, I assume it's your server?

As for my corn plants, I am going to follow your suggestion. I will bare root, trim off the big tangled roots, then repot. But I am having 2nd though about gritty mix as I travel a lot and having to water/fert every other day or so isn't going to work in long term. I am wondering if there's a way to have loose airy soil that that also have enough nutrients without frequent fertilizing.

Just thinking out loud, I wonder a well mixed mixture of 30% compost, 20% crushed granite, 20% lava rock, 30% crushed polystyrene packing peanuts. Compost to provide nutrients, granites to help hold/steady the plants, lava rock to retain water and peanuts to provide air space?

I have been putting packing peanuts to fill the bottom 30% of my big planters to reduce weight and promote drainage for the past few years with no ill effect. I am wondering if I cam expend on that idea?

I have no idea about the pics, though blog.com has a reputation for a lot of down-time. Thanks for letting me know! If you click again another time, hopefully it will work better. Hard to complain much about a free thingie, so I won't. Sorry it frustrated you! The pics here are of a diff plant, but the very same principle.

" I am wondering if there's a way to have loose airy soil that that also have enough nutrients without frequent fertilizing."

Generally yes, a bigger pot/more volume of soil mix. I would forego the styro & compost. The styro will just cause you to need to water (and repot) more often. Fertilizer is much more efficient at delivering nutrients in a pot which is not a large enough environment for the natural decomposition process to appropriately sustain/fortify plants. Also, as decomposition happens, the result is tiny, water-logged, airless particles (mud.)

More about soil/watering.

A Dracaena grows so slowly, an occasional dose of weak fertilizer should be more than enough even in the leanest (nutritionally) mix.

The mix you described, or any with 30% compost would be too dense for my confidence. The goal of a coarser, grittier mix is to eliminate tiny particles of any type, peat, sand, clay, silt. Think moist particles that have some tiny air spaces between them so there is also oxygen, even when saturated to capacity.

It's going way beyond my area of experience to give you a specific recipe since I break the rules I espouse but there are a glut of discussion here about this. I would follow the advice established in those. It gets perpetuated because it works well for so many people/plants. There is a pic of such a mix here, in post dated
Wed, Oct 20, 10 at 9:45.