Whew! That's got to sound like a wackie question to you rose-growers. my mom has always grown her roses outside, but I'm not blessed with a yard. I work well with my huge bay window in my apartment, windows wide open now because of the awful PA hazy hot humid weather.
My new mini-rose blessed me with a new opened blossom. I potted it into a clay pot (it was very pot bound, needed constant watering), and it's getting light all day, and direct sunlight for at least 6 hours every day.
My rose sure looked wilted by the end of the day today. It was well watered. That makes me think too much sun.
Ideas? Feedback? Please don't just yell and tell me "it needs to be outside". The "outside" I have would look like I have put my beautiful new flower on the "free for sale" market.
It is common for a miniture as well as other shrubs to look tired and wilted at the end of a hot and humid day. Does your plant look bright and spry in the morning? The common mistake is overwatering a wilted plant, thus causing the plant to have a weakened root system or even root rot. Only aquatic plants like their feet wet all of the time.
I put all my mini's in the ground this year and not only are they growing in leaps and bounds, but the new growth is larger. The flowers and leaves are both larger. They are doing great. It might not hurt if you put your mini in an oversized pot and tricked it into thinking it is in the ground. My plants get about 6-8 hours of full sun.
Roses really aren't houseplants. They should be grown outside. :) It's very hard to get the balance of light, water, and nutrients right for them inside, not to mention the diseases and predatory insects. However, you seem to be having some success, so you must be doing something right. :)
How large is your pot? "Mini" refers to the size of the blooms, not the plant size, and some minis will get quite large. If your rose isn't in at least a 5 gallon pot, then it's probably too small, and may be enduring water stress because of that. Also, terracotta isn't the ideal pot for roses, as it actually wicks moisture away from the roots. Plastic is much better. If you don't like the look of plastic, then you can line the terra cotta with a plastic pot, and with a little mulch on top of the soil, you'll never be able to tell. Finally, if you repotted your rose recently, then it just may be suffering from a bit of transplant shock, and it will grow out of that in time. Be aware that a mini rose's worst enemy is the spidermite, and that roses grown indoors seem to be especially vulnerable to them. Also, you may need to provide supplemental light, unless that 6 hours of sun is direct, and you you may need to even if it is, because roses under glass need a bit more than 6 hours to bloom really well. Good luck with a really difficult gardening task! Let us know how you do.