One of the best features of growing perennial herbs outdoors is that it’s really easy to do. They’re naturally pest resistant, can tolerate a range of conditions, and don’t need a lot of close attention. It almost feels like cheating! (But don’t worry, all’s fair in love and gardening!) Some of them even have culinary uses or medicinal properties as well, just to add a little something extra to the equation.
Before you embark on your perennial herb-growing adventure, you should inform yourself as to your local plant-growing conditions by consulting the USDA Hardiness Zone Map. This map (freely available on the internet at the United States National Arboretum website – do a search) divides the USA into 11 non-contiguous zones according to how cold they get (higher zone numbers equal warmer conditions). Use this map to determine what zone you are in. Then, for any herb you’re thinking of planting in your garden, look up its ‘cold tolerance’ zone rating (there are plenty of internet sites that have this information – again, do a search). This will tell you whether what you’re thinking of growing will grow well, have a tough time, or turn brown on the first day of fall. If you live outside of the USA then do a search on the weather conditions of your country.
Don’t forget that you can make conditions in your garden easier on your plants than your hardiness zone would suggest by adding features to help it retain warmth overnight. For example, features such as gravel, low stone walls, and stone pavers or stepping-stones will all absorb heat during the day and emit it at night, helping your plants survive the worst of the cold.
The perennial herbs in your garden are going to be around for a while, so (local conditions permitting), you should choose ones you really like. Here are some suggestions for perennial herbs with nice foliage and/or flowers:
- Lavender. Lavender is of course a garden classic. It adds a lovely aroma and a dash of purple to your garden. Note that there are different varieties of lavender, some which can grow as perennials in zones 5-8, but most of which over winter only in zones 7-11.
- Lemongrass. Lemongrass is great as an ornamental grass in your garden, it’s a useful culinary herb, and you can make tea out of it. What more could you want? It’s happiest in zone 9+ over winter.
- Pineapple sage. Pineapple sage has some red flowers that’ll look good in almost any garden. Pineapple sage is a ‘tender’ perennial, meaning that in colder places (below zones 8) it will grow as an annual rather than a perennial. Another variety of sage, purple sage, is also a pretty addition to your garden with vibrant light purple flowers.
- Rosemary. Another famous culinary herb, rosemary smells great and works well as an edging shrub. It’ll survive winters down to zone 7.
- Lemon thyme. Lemon thyme is a pretty low-growing shrub. It’s also very hardy, being able to survive winter in zones 4-5+.
Of course there are many more to choose from, so go ahead, pick out which ones will work best for you and start growing perennial herbs.