How to Grow Mexican Heather. Mexican heather is also known as false heather or elfin herb. Although the plant looks delicate, it's a fairly sturdy shrub. Mexican heather often has purple flowers from spring to fall and it may bloom year round in warm climates.
Think of Mexican heather as an evergreen shrub in areas that do not experience frost. In zones 7 and 8, Mexican heather is more like a perennial. In colder climates, Mexican heather will be like an annual. Knowing your zone and having the right expectations for the plant will help you better care for it.
Start Mexican heather from seeds or cuttings. The plant may also self-propagate in some places. In colder climates, you'll need to restart each year, although you can collect the seeds from the previous year's plants. You can also plant Mexican heather in pots and take them inside during the colder months to keep the plants alive for the next year.
Plant Mexican heather in full sun to areas with light shade. This plant often thrives in the hot, humid weather than can be problematic for many other plants. You may want to plant Mexican heather in slightly shaded places in very warm climates to prevent the blooms and foliage from fading.
Water Mexican heather on a regular schedule, particularly if it's in a pot. You should also fertilize potted Mexican heather regularly.
Trim the heather back if it gets leggy. This happens more with older plants that live in warm climates. If you live in a colder climate, you'll find that it's easier to restart the plants each spring for the best look.