Nope, go ahead and start hardening it off outside. My new minis went right out onto the porch into indirect sunlight. After a few days, you can start giving them some direct sunlight, but if you notice any burning, bring them into the shade.

There is a little info on Lavender at the link below. I don't know how tall it gets, don't be surprised if it grows larger than 18" x 18".

Here is a link that might be useful: What exactly are Sunblaze roses?

Here is what they say on the Website of The Sunblaze series about Lavander Sunblaze-

Large, perfectly formed deep lavender blooms are truly a novel breakthrough in miniature roses. The plant is medium growing and has lustrous burgundy new growth. Try this new color in your garden.

I bought other colors in the Sunblaze series this spring but not the Lavender. They are all supposed to stay about 18 inches tall. I have a Cherry Sunblaze in my garden that I planted last year and it bloomed none stop all summer and fall.

I just love the Sunblaze series.

Thanks for your help. I hope this Sunblaze rose does as well as yours.

Juliet