Gardenia is often found in many home interiors and it bears some of the most beautiful flowers.
General Gardenia facts
Name – Gardenia
Family – Rubiaceae
Type – indoor plant, shrub
Height – 6 ½ feet (2 meters) outside and 1 ⅓ to 3 feet (0.5 to 1 meter) indoors
Soil – soil mix
Exposure – well-lit
Foliage – evergreen
Flowering – May to October
Care, watering, pruning and repotting should help you enhance the blooming.
Planting and repotting gardenia
Growing gardenia isn’t always easy, particular care must be provided to boost gardenia growth and blooming. First of all comes planting and repotting.
Gardenia is most often used indoors in temperate climates because cool winters makes it impossible to grow gardenia out in the open.
- It is recommended to plant your gardenia in good flower plant soil mix.
- Select a very luminous location but without any direct sun.
Planting gardenia outdoors is only possible if the climate is warm in summer and mild in winter, because it cannot survive freezing.
- Choose a spot that is protected from wind, a bit sunny but not too exposed, part shade ideally.
- Mix the earth from your garden to soil mix, heath and dried leaves or river sand.
- Gardenia also requires well-drained soil.
If you’re growing your gardenia in a pot, repotting every 2 to 3 years is prescribed. The plant needs space to grow, and a tight pot would alter its development.
- Wait for the plant to show it needs more space before repotting.
- Best repot the gardenia at the end of winter or at the beginning of spring.
- In certain specialized horticulture stores, special gardenia soil mix can be found.
Propagating your gardenia
The best way to multiply gardenia is cuttings, even though this technique isn’t always crowned with success.
- Prepare cuttings at the beginning of spring.
- Select cuttings about 3 to 4 inches (8 to 10 cm) long.
- Pinch off lower leaves, keeping only the topmost pair of leaves.
- Dip the cutting in powdered rooting hormones.
- Plant the cuttings in special cutting soil mix or in a blend of peat and river sand.
- Place your cuttings in a well-lit place, without direct sun. Ensure air moisture levels stay high (you can cover the cuttings with a garden cloche or clear plastic to increase moisture levels).
- Keep substrate a little moist.
- Repot young plants when the cuttings have already formed nice leaves.
You can also try marcotting (also called air-layering). It’s similar to cuttings, except that the branch remains attached to the plant.
Basically, the goal is to wrap the branch with a clump of moist soil.
Roots will develop. Then, simply cut the branch off and plant it to a pot!
- Scar bark along the branch with a blade (lengthwise, not round and round the branch). It’s ok to remove a sliver of bark and reveal the wood beneath.
- Slip the whole branch through a plastic sheath that’s about 3 inches across and 6 inches long (15 cm). You can also simply use plastic food wrap or swaths of gauze.
- Two inches (5 cm) below the mark, tie the pouch or plastic to the branch.
- Fill it with a blend of soil-mix, sand and garden soil (a few handfuls of each). It shouldn’t be too clayish.
- Extend the soil-filled space along the branch for a further 4 inches (10 cm).
- Moisten the soil (wet but not soggy) and tie the top shut.
Every couple weeks, check the moisture and add water if necessary.
- An easy way to do this is to have a small slit in the plastic.
- You can stick your finger in it. If it feels dry, squirt water in with a hand spray (a syringe is easier).
- Close the slit with tape.
Voilà! Your marcot is going to sprout roots in the area with the soil. This will take around 3 to 4 months at most. At this point, you can cut the branch from the mother plant at the bottom of the marcot and pot it up. Remember to keep the plant away from direct sun at the beginning, until roots develop more.
- Again, ensure moisture in the air to make sure your marcotted branch survives.
Gardenia doesn’t like hard water, so it is always best to water from collected rainwater or bottled mineral water.
- It needs to be watered with rain water or mineral water if the water from your tap is very hard.
- It also requires constant moisture levels.
- During the blooming, take care not to get the petals wet, since this will cause blemishes on the flowers or discolor them.
How to provide constant air moisture
To recreate the moisture in the plant’s natural environment, you can place the pot on a bed of clay pebbles or gravel, and ensure the space between these is filled with water.
- other ways to ensure humidity around a plant
The water will slowly evaporate and remain in the vicinity of the plant: you have just re-created the plant’s native tropical environment!
Watering gardenia in spring and summer
It is important to water regularly without flooding the plant.
Wait for the surface of the soil to have dried out before watering again. Since gardenia needs very moist air to grow well, spray water on the leaves, but stop doing so as soon as the plant is in full bloom.
Watering your gardenia in fall and winter
Reduce the watering. Wait for the substrate to have dried out down to about as deep as your index finger will reach. When the soil is dry to that point, water again.
Pruning and caring for gardenia
After the blooming, prune your shrub lightly to retain its tight, compact shape while reducing the branches by ⅓.
Remove wilted flowers regularly, since this stimulates production of new flowers.
In order to reinforce the plant and produce spectacular blooming, provide it with special heath plant fertilizer.
Repotting in spring every 2nd year in a blend of heath and soil mix is needed to bolster proper plant growth.
Diseases and parasites that attack gardenia
When grown as an indoor plant, gardenia may encounter most diseases, insects, parasites and mites that attack house plants in general.
Most common parasites are aphids, scale insects and red spider mites.
- Here is how to fight off scale insects
- How to effectively stave off aphids
- And lastly, how to treat against red spider mite
Note that if your gardenia leaves turn yellow, but the veins and ribs stay green, you’re probably dealing with chlorosis resulting from water that is too hard.
If the flowers fall off before opening up, lack of ambient air moisture is certainly the cause. Spray soft water on the leaves and unopened flowers, but stop when the flowers have opened up or spots will appear.
Learn more about gardenia
Native to tropical and sub-tropical regions of Africa, Asia and Oceania, people usually love it for its abundant flowering. Additionally, gardenia releases a soft jasmine-like fragrance.
This plant will adapt to living indoors very well, as long as moisture levels are very high. Never place it near a radiator or heat source. It’s important to keep it from dehydrating.
Outdoors, it requires very mild climate, without any frost or freezing in winter.
During winter, freezing would kill the plant, and you’ll have to bring it inside for protection.
Smart tip about gardenia
After having purchased your gardenia, wait for the blooming to end and repot the plant: this will stimulate development and proper growth.
Credits for images shared to Nature & Garden (all edits by Gaspard Lorthiois):
Hazy gardenia flower by Carol VanHook under © CC BY-SA 2.0
Gardenia blooming from above by Jorge Elías under © CC BY 2.0
Gardenia cut flower by Ho John Lee under © CC BY-NC 2.0