I have a lavender plant that I have in a pot. I brought it inside to my greenhouse. It is 80 in the day and 60 at night. How often should it be watered? I did do the cutting back to half its height. This was its first year and it did not flower.

When the soil is more dry than moist, but not totally dry. However, contrary to common misconception, lavender likes regular water but hates steady wet roots. The most important factor is the drainage of your potting soil. If it is too peaty and retains moisture at the bottom of your pot, it will be difficult to maintain a good balance. A very fast draining potting mix will allow you to water regularly without risking root rot.

I've never grown lavender in a greenhouse so I can't advise from experience. My lavenders survive winters here outside. Perhaps you are trying to get winter blooms?

Could I actually get winter blooms? Would it be better to put it in an unheated garage ? Still water when dryish?

So sorry, I have no idea whether you can force lavender to bloom off-season in a greenhouse. I've always experienced lavenders as late spring/summer bloomers. Some lavender species are more cold-hardy than others. Have you researched the cold tolerance of yours? Winter protection of potted plants is usually needed in hard freezes. I often use bubble wrap around the pot and keep it in a protected area. Garage, if lighted, could work. Your greenhouse might be fine. The temperature seems high, but again, I don't have greenhouse experience.

This appears to be a very comprehensive article about lavender culture. Perhaps it will answer some e of your questions

https://www.gardenerreport.com...

It is a hybrid that tolerates down to zone 5. I read the article . I think i will just put it in the unheated garage.

Good info to have. For future reference, potted plants are hardy 1-2 zones higher (warmer) than when planted in the ground. So your lavender rated hardy in zone 5 in the ground might be at its limit in zone 7 in a pot, so protecting it in your garage sounds wise.

One other comment: most lavenders are pretty tough except when they get soggy. I've lost way more of them to overwatering than freezing.