I grow Phlomis tuberosa in the northern part of zone 3. It winters just fine. This is a large plant (4 feet tall) with somewhat coarse leaves. It currently is blooming and I would describe the flower color as leaning toward the lavender tones. A pinkish-lavender? After blooming the flower stalks can be left on for winter interest or the stalks can be cut back, leaving a low clump of foliage. In my garden it flourishes on a sunny site on well-drained soil. I have never been able to successfully start this plant from seed but that certainly does not mean it can't be done. Usually P.tuberosa is rated as a zone 6...sometime as a zone 5. Ridiculous! If I remember correctly, there are some zone 2 gardeners in Canada growing P. tuberosa.

Phlomis russeliana is slightly shorter (3 feet) and has yellow flowers. It is usually rated zone 4. I do not grow this but would like to try it. Phlomis fruticosa also has yellow flowers and is usually rated zone 6.

Jan