Hey Maisha! Welcome to the forum :) Hoya naturally grow along trees, collecting nutrients from the crooks where leaves and bird droppings fall.. So they like to have air around their roots and (most) like to dry between waterings.

I've read over and over that the soil is one of the most important parts of your plants growth. Ideally you want something that the water "runs right through." It's been recommended to use a mix with bark.. but I haven't been doing that yet. You have had the cuttings for a year, plus new growth shows that they have been surviving! I wouldn't stress over the soil, but it is a place to look for making ideal changes.

I think I remember reading that a cutting from a mature plant will do better than a cutting from a younger plant. That could effects time until flowering. Even so, when a plant is grown from a cutting it usually takes a few years.

As for giving it a trellis, it will definitely effect how your plant looks! I don't think it changes the plants growing speed, but that's a good question! Twining, climbing hoya DO want to grow UP. But that usually just effects where the plant focuses it's growing energy. (Leaves on a stem pointing down vs create a new stem to try and grow UP)

One last bit of info! I do know that hoya sent out shooters (tendrils) sometimes to look for different living conditions. 'Is there more/less sun/heat/draft/moisture over there?' But i'm pretty sure that some hoya just have those tendrils either way!

Hope that helped, someone with more experience will probably pip up with more/better info :)

Keiko

One thing I learned this season is to point the growing tips upward if you're growing on a trellis. Believe me it makes such a difference with my slower growing hoyas.

Some hoyas naturally hang down but I think you'll be able to tell the difference after you see more growth.

Best wishes with your plant. Carnosa is my very favorite and I would love to have cuttings off an old plant.

Susan

Not all Hoyas are twining vines but I do believe that the species that are do grow significantly faster when they are allowed to climb as they wish. Most of us do not have the space to let our Hoyas grow wherever they wish so we use trellises. I have experienced many instances of growing tip die back on my Hoyas when manipulating vines onto the support and I truly believe that if I just let them do their thing that this would not happen.

I attached a link to a video of a time lapse showing how twining vines find support and then quickly climb. Hoya carnosa is not a strongly twining species but it will search for and use support.

Mike

Here is a link that might be useful: Time lapse of vining plant