Personally I would have patience and use a slow release organic liquid fertilizer that doesn't burn tiny rose roots for the first year.
I have a clay based soil that gets top-dressed with organics and it holds nutrients longer than other soils types,so, sometimes I do not even use fertilizer the first year.
Your in a totally different climate and I have no idea what soil type you have or the condition of your soil, etc.
Just keep the rose watered well and avoid using full strengh chemical fertilizers that may burn your rose roots.
Make sure the rose is well hydrated with water before adding fertilizer to the soil.

Sorry -- baby roses need to be baby roses for a year or two. Can't rush Ma Nature, and if you try, she WILL retaliate. Take it easy, and use organic and/or slow release fertilizers only for now.

Remember for climbers, the first year they sleep, the second they creep and the third they LEAP. If you bought bareroots, you probably jumped into the second year. If you bought bands, then you're still in step one of that series.

Patience, my dear.
Kathy

Fish emulsion at 1/4 strength every couple of weeks.

When it gets hot, for the first summer, shade them with an umbrella or shade cloth in the very hottest part of the day.

Plenty of water (but don't drown them).

Mulch the soil with 2-3" of quality organic compost, keeping the mulch at least an inch or two away from the base of the plant. Re-add compost as necessary.

You want to provide optimum conditions for the fastest growth.

Still, as has been said, climbing roses are generally a multi-year project.

I have heavy clay soil but was amended well with mg garden soil & composted steer manure.

They were all bareroot plants.

They will have a drip line & get the right amount of water & will have good amount of mulch. They will only get afternoon sun so if I shade them in the hottest part of the day, they may not get any sun. All conditions should be good, except the "sun" thing.

They've got about 12" of growth already.

When you say "amended well with mg (Miracle Gro) garden soil", was this on top or in the hole? I ask because with lighter soil in the hole and clay all around, you risk "the bathtub effect" where water cannot drain out of the hole properly.

And I agree with the others, rose growing is one of patience, not speed. Dilute solution of fish emulsion would be good for the first year.

Just keep an eye on them as far as the hottest part of the day especially during heat waves. If they wilt or look toasted, they need some protection. If they don't wilt and the canes don't look burnt and the leaves don't look burnt, they are fine.

Just observe as much as you can--the best teachers are the plants themselves! :)

Just keep in mind that climbing roses are more like small trees than like "regular" rose bushes. It takes them a few years to become substantial enough to be a presence in the garden...