Hi Traciann and welcome to the metroplex! I'll cover the plants that you have that I know about. The hydrangea will be fine outside, it's good to zone 4 and you are likely in 7b. The knockout rose will be fine outside too. Purslane is an annual and super inexpensive to replace in the spring...mine always get too leggy and unattractive after summer anyway. What type of pots are they in? Glazed ceramic pots will crack if we have a wet-cold spell. The moisture will cause expansion and the ceramic will crack, otherwise you will need to do nothing special to those plants.

Plumeria is tropical, do you have a sunny window or patio door for it to sit near? I *think* the lime will be too tender for our winter too, but someone else will likely add their knowledge.

Pam

I'm from the California side of part of the Arizona desert (Mohave on your side, Mojave on mine)and now I live in DFW. Never gardened in water like Houston tho.
If you need the 2 "secrets" to houseplants I can tell you how. Don't water unless it's dry 1 inch down in the soil and raise your plant's pot OUT of the basin that catches water. I use bricks or rocks. That's it.
Plumeria are NOT houseplants without a greenhouse. They will get all yucky on you and look hideous. They do well going dormant. Stick it in the garage and forget it until the last frost. Take it back outside and water it. Leave it alone until it's dry 1 inch down before watering it again. Do the same with the citrus.Keep the tree out of direct sunlight and let the roots cool, but maintain overall temp above 40.
Purselane I have no clue.
I've never had a rose in a container but I'd throw something over it or put it in a protected corner. The roots are very vulnerable in a pot. PJ

I've had my Plumeria for two years and all you need to do is put it in the garage and DO NOT WATER IT till spring. It will loose it's leaves and that's ok. It will come back come spring time, once all danger of frost is over put the Plumeria outside give it a good watering wait a week and then water again then fertilize it. I just use MG.

For the Roses they will be fine in the pots outside. I have about 5 in pots year around. No need to wrap the pots on them.

I have over wintered purselane but it get's really leggy and ugly and lots of bugs. I've done it both inside and in the garage, in the garage I cut them all the way back and left them alone, come spring time I place the pots outside and water the dickens out of them. They really do well if the get lots od rain water. IMO I don't think they are worth the hassle, That's why now I'd buy them each spring if I want some and I love Purselane and usally do buy a few.

I don't know what the green with purple flowers ground cover thing's are in with the roses but you might try digging them out and putting them in another pot?

You can keep the lime tree inside.
I had french doors and kept it there. That way I could move it out on pretty days.
Welcome to TX gardenweb.