Hummingbird mint is a popular flowering plant that is known for attracting hummingbirds. It has bright purple flowers and a minty aroma. Many gardeners grow hummingbird mint in their gardens to enjoy the beauty of the flowers and the frequent visits from hummingbirds. One common question about hummingbird mint is whether it comes back every year. The simple answer is yes, hummingbird mint is a perennial plant that will return each spring. However, there are some factors that affect hummingbird mint’s hardiness and winter survival. Let’s take a closer look at hummingbird mint and what is required for it to return year after year.
Hummingbird Mint Overview
Hummingbird mint (scientific name Agastache) is a genus of aromatic herbaceous perennial plants in the mint family Lamiaceae. The genus contains around 30 different species, many of which are native to North America. Some common species used in gardens include anise hyssop (Agastache foeniculum), giant hyssop (Agastache scrophulariifolia), and purple giant hyssop (Agastache rugosa). The flowers bloom on tall spikes from midsummer to early fall and come in shades of purple, blue, yellow, orange, red, and white depending on the variety.
In addition to attracting hummingbirds, hummingbird mint is also attractive to bees, butterflies, and other pollinators. Deer tend to avoid it due to its strong minty scent. The aromatic leaves can be used to make herbal tea. Hummingbird mint grows best in full sun with average to dry soil that has good drainage. It prefers drier conditions and may rot if overwatered. Mature plants can reach 2-4 feet tall depending on the variety.
Winter Hardiness
Hummingbird mint is winter hardy in USDA zones 4-9. This means it can withstand minimum temperatures from -20°F to -30°F. Varieties like anise hyssop and purple giant hyssop are some of the most cold hardy types. In warmer zones like 9-11, hummingbird mint may stay evergreen all year. But in colder zones, the above ground foliage will die back once freezing temperatures arrive. The plant retreats its energy down into the root system. As long as the roots are planted below the frost line, they have a good chance of surviving the winter.
There are a few factors that affect hummingbird mint’s winter hardiness:
- Plant variety – Some varieties are less hardy than others. For example, scarlet sage is only hardy to zone 6 while anise hyssop can survive colder zones down to 4.
- Age of plant – Younger plants are less established and may have smaller root systems, making them more prone to winter kill.
- Soil conditions – Very wet soils increase the risk of rot over winter. Good drainage improves hardiness.
- Mulching – A 2-4 inch layer of mulch over the roots provides insulation and moisture retention during dormancy.
- Exposure – Plants in exposed, open areas may suffer more winter damage from drying winds.
Gardeners in zones 5 and below should choose hummingbird mint varieties suited for their climate and take steps like mulching to improve the plant’s winter survival. Proper care will maximize the plant’s chances of coming back healthy each spring.
Spring Regrowth
As spring arrives and the soil warms up, dormant hummingbird mint roots will begin sending up new growth. This typically occurs after your region’s last expected frost date. Hummingbird mint emerging from dormancy starts as new shoots from the base of the plant. As temperatures reach into the 50s and 60s°F, top growth will take off rapidly. Flower stalks will follow later in early to mid summer.
It’s important not to jump the gun by removing any dead growth left over from last year too early. This residual foliage provides some protection for the new shoots against any late frosts. Once nighttime lows remain above freezing, you can trim away last year’s dead growth to allow the new foliage to fill in.
To encourage vigorous regrowth, fertilizing is recommended in early spring once there are several inches of new growth. Use an all-purpose fertilizer like 10-10-10 or something formulated for flowering plants. Always follow label directions on any fertilizer products.
Hummingbird mint’s spring foliage fills in quickly and soon the plant will be bushy and full again. Flowering typically begins in mid to late summer. With proper care, healthy plants can live for 5 years or longer.
Signs of Trouble
Sometimes hummingbird mint may not come back as expected after winter. There are a few signs that indicate the plant may be struggling:
- No new growth by early summer – If you don’t see any signs of life by early summer, the roots may have died over winter.
- Weak, spindly growth – Sparse, weak growth can mean the roots were damaged and are having trouble supporting the plant.
- Widespread dieback – If new shoots emerge then suddenly die back, it indicates a problem like freezing damage.
- Stunted size – Plants that remain small and never reach their expected mature size may be weakened.
Troubleshooting is needed if you notice any of these issues. Start by digging around the base of the plant looking for healthy white roots. If none are found, the plant likely didn’t survive winter. If the roots look healthy, other issues like poor drainage, disease, or fertilizing at the wrong time may be to blame.
How to Encourage Return Growth
Here are some tips to ensure your hummingbird mint returns reliably each spring:
- Select winter hardy varieties suitable for your climate zone.
- Plant in a sunny spot with well-draining soil.
- Avoid overwatering which can lead to rot.
- Cut back stems at the end of the season but leave basal foliage for insulation.
- Apply 2-4 inches of mulch around the base in late fall after the ground freezes.
- Fertilize plants in early spring to fuel regrowth.
- Divide large clumps every 2-3 years to promote vigor.
- Prune out any dead stems once new growth is several inches tall.
Growing hummingbird mint in the appropriate environment and providing proper care will give you the best chance of success overwintering it. Well-established plants have an extensive root system that can withstand cold winters and readily regenerate each spring.
Overwintering Potted Plants
Potted hummingbird mint plants require extra protection in order to survive cold winters. Since containers are more exposed than in-ground plants, frost damage is a bigger risk. There are a few ways to help potted hummingbird mints make it through winter:
- Use containers just a bit larger than the root ball so excess soil doesn’t hold moisture.
- Before first frost, move pots to an unheated garage, basement, or covered porch.
- Group plants together and wrap with burlap or bubble wrap to insulate.
- Water sparingly over winter, just enough to keep soil barely moist.
- In spring, remove any dead growth and repot into fresh soil if needed.
Protecting the roots from hard freezes is key. An unheated space that buffers pots from dramatic swings in temperature but remains cold provides ideal overwintering conditions. With proper care, container-grown hummingbird mints can successfully come back the following season.
Can Hummingbird Mint Be Invasive?
Hummingbird mint is not considered an invasive plant by most botanical sources. While it spreads via underground rhizomes like many mints do, it tends to grow in well-behaved clumps rather than spreading rampantly. Containing hummingbird mint is fairly straightforward:
- Plant in a pot or container to restrict spread.
- For in-ground plants, allow a couple feet between other plants.
- Trim flowering stems after bloom to reduce reseeding.
- Divide large clumps every 2-3 years to rejuvenate plants.
- Pull out unwanted spread around the edges.
The aromatic qualities of hummingbird mint also help restrict its spread. Chemicals in the leaves discourage growth of surrounding plants. Maintaining good air circulation around the plants also keeps them in check. With simple care, hummingbird mint can be grown successfully without becoming a nuisance.
Companion Plants for Hummingbird Mint
Here are some great options for companion plants that pair nicely with hummingbird mint:
Shrubs
- Butterfly bush
- Hydrangea
- Rose of Sharon
Flowers
- Bee balm
- Black-eyed Susan
- Coneflower
- Coral bells
- Lilies
- Salvia
Herbs & Vegetables
- Basil
- Beans
- Carrots
- Oregano
- Tomatoes
Grouping hummingbird mint with other nectar-producing blooms will draw in more pollinators. Vegetables like carrots and beans appreciate the pest deterring qualities of mint. Choose companions with similar soil and sunlight needs for compatibility.
Conclusion
In summary, hummingbird mint is a hardy perennial that provides seasons of beautiful flowers and irresistible fragrance when given proper care. Selecting varieties suited for your growing zone, providing protection in winter with mulch, and discouraging spread will allow hummingbird mint to thrive. With the right conditions, there’s a good chance this favorite flowering plant will return dependably year after year to brighten up your garden.
