I will be visiting a friend in Huntingtown MD next month and I want to bring some plants to share with her. I have looked up hardiness zones and come up with zones 7a, 7b, and also just plain old 7. I will be bringing old standbys like daylilies and iris but I also have tropicals that I would like to bring her. I'm interested in your experiences about overwintering some of these plants outside.
Cannas, hedychium gingers, Colocasia, crinum, maybe a basjoo banana one day. I've read that Ellen Bosanquet crinum is hardy there.
Any experiences are welcome and any help is not just limited to MD.

Kabby--Other than the cannas--I believe all the rest of the plants you listed are tropical.

The only plant i can advise you on are cannas--in at least what I do.....
At least from my experience--When real cold or a light frost comes--
Cannas need to be allowed to have their leaves lightly frost-nipped. The leaves will be all limp.
Cut them all back--leaving ~ 8"stem-bundle sticking up. This will help as a "handle" to lift the roots up.

Wait about 2 more weeks and then dig the whole root mass up. be careful!
You can, gently, try to knock some of the lg. clumps of soil off--BUT--be careful--as the new pips
are quite fragile and tender at this time and can be broken off.
***Allow the roots to dry. Spread on some newspaper on a mild, breezy day to do this.
Roots need to be dry before you store them--or they will rot in a cool basement.

Store in your basement/laundry room in an open cardboard box for the winter.
Some crumpled newspapers can be, loosely, put on top.
Do not water! Just let them be for the winter.
In spring--take a peek and maybe mist the roots a bit now and then.

When it is time to plant--VERY gently, separate the clumps. You can break off, and remove, the old roots.
They have done their job!
The red, firm pips sticking up will be where the new stems will grow from.Try not to damage these.

Plant roots about 4" deep in a sunny area and water in. Wait! Water a bit as you wait.
It may take a couple weeks before you see new growth.

Now--there may be people that allow their cannas to remain in the beds as planted for the winter.
I suppose some Folks have protected. mulched areas and the Canna roots can stay in the ground.
I will let those folks to tell you what they do.

Hope this helps. Gita

Huntington looks like it is in Southern MD near the bay. That may be a little bit warmer than central MD where I live. Generally, none of those things you named are considered reliable to leave out through central Maryland winters. I don't know if that area is much different.

Crinum, I think are OK overwinter, Canna overwinter might make it if mulched and winter isn't too bad. There are certain gingers hardy here. And microclimate matters, whether your friend can place these things against a south facing wall, (warm) or if they will go instead on the north (cold). I got two crinum bulbs and they have lived through two winters in my south facing bed. I left canna out one winter and left the big leaves and stems over them but they were very wet and slimey by spring.

These are good tips. That's what I'm talking about!!

Hardy Banana basjoo is hardy here - 7b. Plant where the wind is least likely to tear the leaves, mulch well or leaf cage for winter. I grow all of my colocasia and alocasia in pots/containers which I put in my unheated porch (doesn't freeze) and let them go semi dormant for the winter, withhold water until ready to set back out in Spring.

colcasia and dahlias

I just left mine in the pots and brought them in and left them in the family room. I didn't water until I saw new growth. They did fine. I did the same with a pineapple plant and my gingers.

Yehudith