You could certainly grow most highlanders in zone 9 during the growing season. Bring them indoors or provide them with some kind of protection in winter as they really do not like temperatures lower than 40-50 degrees consistently. They do not go dormant and will not enjoy a low light, cool winter. I keep mine indoors and provide 16 hours of florescent light to supplement the direct south windows they get all year round. Just the windows or florescents alone are not sufficient once they get over a foot tall. Mine stopped pitchering until I got a better setup with both light sources hitting it at one time. In winter outside it might be O.K. if it does not get a very cold winter. I would err on the side of caution even in zone 9 and keep it protected just in case a cold snap hits and brings the temps down near freezing for a day or so.