For those of you in warmer climates, gardenias are stunning, scented plants for the landscape or outdoor container. Meanwhile, for those of you who are in a colder climate, you can grow this plant indoors.
Either way, you’ll feel the scent of this sweet perennial year after year.
Gardenias are evergreen shrubs, typically suited to USDA Zones 8 through 11. What I love about this plant are its fragrant creamy white flowers and thick, glossy leaves.
Thanks to intelligent cultivation, some new varieties are known to survive in Zone 7 or even Zone 6.
Gardenia actually originated from China and Japan, but it was named after Alexander Garden, a Scottish doctor who lived in Charleston, South Carolina in the late 1700s.
Gardenias can grow up to 8 ft tall, but some varieties are shorter. Most of the long-lasting blooms come out in the summer and semi-summers, but some varieties bloom again in the fall.
No matter what season it is, if you have a gardenia in your garden someone will smell it before they see it.
How to Use Gardenia
Gardenias can be versatile shrubs if planted in the right spot and will flourish for many years.
In the Landscape
Gardenias are hardy plants and can be used as accents in shrub borders or landscape decorations. They should be planted near a path, deck, patio, pool, or other sitting areas so that you can really enjoy their sweet fragrance.
Pair them with classic shrubs like roses and hydrangeas for a beautiful garden display!
The best way to grow plants in colder zones is by planting them in pots.
You can enjoy your houseplants during the winter and then outside for the warmer months, just make sure to combine them with purple heuchera for contrast.
Also, read about 8 aromatic indoor plants for your home.
How to Grow Gardenia
Gardenias typically do best in full sun but may need a bit of shade during the hottest part of their hardiness range. They seem to grow best in humid areas and don’t sustain well under drought or arid conditions.
Plant a gardenia shrub in a wide hole of soil amended with bark or compost to help with drainage. Plant in acidic soil with pH 5.0-6.5 in fall or spring.
Gardenias like plenty of room for their roots to spread out; the plant should be planted carefully and then not disturbed afterward.
Outdoor gardenias will do well in raised beds, where soil can be amended easily with no risk of standing water; indoor plants need to get enough drainage without being left in a saucer that allows them to stay wet.
Also, read about other types of white flowers.
Watering and Mulching
Gardenias need a minimum of one inch of water every week. Apply mulch to a depth of two to four inches in order to keep the soil moist and control weeds that are thirsty for water.
Don’t let the plants go completely dry before you water them, and make sure you give them regular watering. If you’re not consistent, buds and leaves may drop off.
If your plants are fond of acidity, you can fertilize them in spring and again in summer. Make sure to follow the instructions on the label.
You may also want to consider fertilizing with coffee grounds that provide a slightly acidic mulch or blood meal which will help raise acidity levels if they’re low; fish emulsion is another option.
You don’t have to worry when the heady milky white flowers turn brown. This doesn’t mean your bush will die, but that the flowers have faded.
If this happens, do the following:
- Trim the tips right after flowering but don’t trim the bushes later than August; or
- Reduce blooming by removing buds that have already formed.
- If gardenias are grown under the right conditions, very little pruning is required.
Fall is a great time of year to put down mulch around plants. This will help protect the roots from winter cold when it starts dropping below 15 degrees Fahrenheit, so make sure you cover your plants with breathable fabric or some other material on those cold nights.
One of the easiest shrubs to root is gardenia. All that you need to do is cut off a tip from any branch, strip it of blooms and leaves, then stick it in a bottle filled with water where roots will become visible days later.
The cutting can be planted within one month’s time!
Gardenias thrive in heat and humidity, so you’ll need to mimic those conditions indoors.
Place your plants in a room that has a temperature of 55 to 75 degrees Fahrenheit and provide plenty of bright light for them, but keep them out of hot or direct sunlight.
You can increase the humidity by growing plants outdoors on top of trays with some pebbles and water or by using a humidifier-or simply misting the plant with water every couple days.
Common Gardenia Problems and Solutions
They are fussy plants and it is hard to get them right. Even when the gardener has good intentions, they may still find themselves getting into problems.
Alkaline soils or hard water can cause leaves to turn pale green or yellow between the veins. This means that chlorosis has occurred and an iron supplement is needed.
To treat chlorosis, add a mulch of sulfur (according to package instructions) 3 feet away from the plant; alternatively, add chelated iron directly onto leaves- this will help raise pH levels in soil and keep them there for prolonged periods of time using slow-release fertilizers for acid-loving plants.
Whiteflies and Aphids
Gardenias can be plagued by pests, like whiteflies and aphids. They leave a sticky residue behind- but don’t worry! Simply wet the plants down with soapy water or insecticidal soap, then rinse them off with clear water.
Selected Gardenia Cultivars
Gardenias are known for their sweet scent, and they come in more than 250 species. They can be used to create a pleasant atmosphere on patios and walkways or even in containers. Here is just a handful of them to seek out:
Veitchiana (or Veitchii) – Dense, compact plants with double white flowers that grow slowly and make a great addition to containers.
Mystery – the leaves and flowers are larger than those of most gardenias, and it tends to grow better too.
Radicans is a type of dwarf, spreading gardenia that can often be used as a groundcover.
Summer Snow is a newer cultivar that’s cold-hardy enough to grow even in USDA Zone 6 with protection from freezing temperatures around the lower trunk.
Sweet Star is a hardy plant that can survive in Zone 7 and originates from seeds collected at the Beijing Botanical Garden.