Many people enjoy growing gardenia shrubs outdoors. Sadly, few people realise that it is also possible to grow gardenias indoors. This is a great option if you have little or no outdoor space. Growing gardenias indoors is a great way to enjoy the plants showy foliage and attractive, scented flowers.
The gardenia is a member of the Rubiaceae family, the same family as coffee plants and cinchona. Gardenia jasminoides is native to China and Japan, outside these plants particularly thrive in the West and South coasts of America. This means that they are appropriate for gardeners in USDA planting zones 8 to 11. Gardeners outside of these zones will have more success if they grow the plants indoors.
If you want to grow gardenias indoors you need to replicate the plants preferred environment. While this may be challenging it is well worth the effort.
To successfully grow gardenias indoors you need to provide the plants with slightly more care and attention than other houseplants. However, once you find the right position and establish a routine, even the most difficult gardenias growing indoors will thrive.
If you grow gardenias indoors in ideal conditions the plant can achieve a spread of between 2 and 6 ft. Pruning and regular attention can control this spread if space is at a premium. This guide provides you with all the information you need to successfully grow gardenias indoors.
Varieties of Gardenia
If you have enough space and time it is possible to grow all gardenias indoors regardless of the variety. Before purchasing a variety do your research so that you know you are able to accommodate the plant’s growth habit and spread.
Single flowering varieties such as White Gem are ideal if you want to grow gardenias indoors. This is a low growing plant, reaching no more than 2 ft in height, that also thrives in containers and baskets. Kleim’s Hardy is another robust, compact cultivar. Its growth habit rarely exceeds 3 ft in height. The plant is popular because it reliably produces fragrant flowers during the summer months.
Gardenia flowers come in a range of shapes, sizes and colors. To successfully grow gardenias indoors take the time to find a cultivar that best suits your home and conditions.
A more colorful variety is Golden Magic. Reaching about 3 ft in height, and with a spread of only 2 ft, its flowers open white but turn to a deep golden shade as they age.
If you have a little more space, grow medium sized plants such as Veitchii reach around 4 in height. However, the spread of the plant can reach up to 6 ft if it is allowed to. This cultivar produces small, attractive flowers from the spring until the fall. The plant may also flower during warm winters.
Another suitable variety for indoors cultivation is Chuck Hayes. This has a height and spread of 4 ft, flowering during the summer and fall. It is also more cold hardy than other cultivars.
Planting a Gardenia Indoors
Many gardeners like to repot a plant soon after acquiring it. This is because plants sold in nurseries or garden centers are often sitting in containers that are snug or compact. Repotting into a slightly larger container gives the plant room to grow. It also allows you to put the plant in fresh, enriched soil, giving it an extra boost.
To successfully grow gardenias indoors for a number of years you may also need to occasionally repot the plant. As plants grow they can become pot bound, this means that the roots are too large for the container.
Unlike other indoors plants, gardenias have a slow growth habit. This means that they can take many years to fill their container. So while you will have to repot the plant eventually it won’t be an annual task.
The most obvious sign that your plant is outgrowing its home is roots sticking out of the bottom of the container. Plant growth may also slow or cease, Another indication that the plant is pot bound is that the soil may dry out more quickly than usual.
Like other indoors plants, gardenias require a container that has drainage holes in the bottom. Clay or terra cotta containers are preferable, these help the soil to dry out between waterings, helping to prevent issues such as root rot. Plastic containers can also be used but are more prone to water retention. If you are concerned that you may forget or not have time to water your plant, a self watering pot is a great solution.
What Type of Soil?
To successfully grow gardenias indoors use well draining, good quality, fresh soil. A soil mixture containing peat moss and coarse sand is ideal. A handful of acidic compost, or ericaceous compost, mixed into the soil will help to raise acidity levels slightly. This is ideal for gardenias.
Ericaceous compost can be purchased from a gardening or home improvement store. Rhododendron soil is also appropriate for gardenias. This is because both plants require the same acidic soil conditions.
The pH level of the soil should be between 4.5 and 6.0. While gardenias tolerate acidic soils they struggle in soils that are too alkaline. A soil that is too alkaline can cause foliage to yellow and fall from the plant. It can also prevent flowering.
Use a soil that is neutral or slightly acidic in nature. Gardenias prefer acidic soil profiles and tend to struggle in conditions that are heavily alkaline in nature.
The pH level of soil naturally changes over time as you water and fertilize the plants. To check that the soil profile is still ideal for your plant use a soil pH test kit to regularly monitor the soils condition. Many, such as the PentaBeauty Soil Test Kit, not only measures the pH level of your soil but also measures the light and soil moisture levels. This is particularly useful for indoor and container gardens.
If the soil becomes too alkaline an application of diluted vinegar can be poured onto the soil. Leftover, cold tea can also be applied as can organic coffee grounds. To apply the coffee grounds place them on top of the soil and then water the plant.
How to Repot Gardenias
Carefully remove the gardenia from its container. Your new container should be clean and about 2 inches larger and deeper than the old container.
If you have trouble removing the plant squeeze the sides of the container. This loosens the soil allowing you to slide out the plant without causing unnecessary damage.
Carefully brush away any dirt or compost from the root system.
Fill the new container about a third full with your chosen soil mix. Position the gardenia so that it sits in the center of the container. The top of the root ball should sit just below the intended soil level. When you are happy with the position of the plant, fill the container with soil. Gently firm the soil down. Water well.
After planting and watering add a layer of mulch to the top of potting soil. An organic mulch is particularly useful. Organic mulches help to keep the soil moist and maintain humidity levels. Additionally as they break down and decompose they restore nutrients to the soil, giving the plant an extra boost.
How to Grow Gardenias Indoors
Once planted, the grow gardenias indoors process is pleasingly easy. The most important thing to get right is the position of the plant. Remember, despite their robust appearance, these are sensitive plants. Try not to move the plants between positions too often. This can stress the plant causing it to drop foliage, flowers or buds.
Light and Position
If you want to successfully grow gardenias indoors you need to position the plants somewhere filled with lots of bright light. Ideally your gardenia plant will receive between 6 and 8 hours of light every day.
A bright, sunny spot, such as a southeast facing window is ideal. This position provides the plants with lots of morning sun as well as light for most of the day.
Beware that during the summer months, plants placed in windows are susceptible to scorch or sunburn. This causes the foliage to brown. More extreme cases can cause the plant to wilt.
Moving plants slightly further back, so that they aren’t directly in the window helps to prevent this. Alternatively placing a blind or net curtain in the window protects the plant while still allowing it to receive lots of bright light.
During the fall and winter don’t worry if the plant isn’t receiving as much light as during the spring and summer. Exposure to darker periods during the winter months encourages the plant to flower during the following spring.
While the gardenia is a light loving plant, they can survive and flower with just 4 hours of light a day. Plants in darker positions may not flourish as well as plants in brighter spots. In darker homes, or if you are unable to provide enough natural light, try placing the plants under a grow light. This is a great way to provide plants with lots of light.
Gardenia plants prefer cooler temperatures, around 65 to 70 ℉ during the day. Regular exposure to temperatures over 70 ℉ can cause the plant to drop its buds.
Allow the temperature to fall to around 60 ℉ at night. Cooler temperatures at night encourage the plant to set buds.
During the warmest summer days the plants can be placed outside in a shady corner of a patio or balcony. Remember to bring them back inside as temperatures fall.
Your plants should be placed somewhere where air can circulate freely. Keep your plant away from any drafts. Also don’t place it near a direct heat source.
Gardenia plants love light, warmth and humidity. However, exposing the plants to cooler nighttime temperatures encourages them to set flowers.
Humidity levels should be moderate to tropical. This can be difficult to achieve, especially during the colder months of the year when indoor heating is in regular use. Indoor heating systems can quickly dry out the air, lowering humidity levels.
Grouping plants close together is a reliable way to raise humidity as is misting. When misting your plants try to avoid spraying the buds and flowers. This can cause the flowers to fade or lose their color.
Too much moisture on the foliage can also lead to fungal growth. Placing the plants in a position which is well ventilated helps to prevent this.
During the winter months, plants require more frequent misting. This is because central heating can dry the air out, lowering humidity levels.
You can also place the plants on a humidity tray, such as the Humidi-Grow Humidity Tray. Alternatively you can make your own by filling a tray with pebbles and water. Just make sure that the container is sitting on the pebbles and not directly contacting the water. If you choose to use a humidity tray remember to regularly refill the water as it evaporates.
If your bathroom is light enough this could be the ideal position to grow gardenias indoors. Bathrooms, thanks to all the hot water we use, are naturally humid environments and can be the perfect home for tropical plants.
Water and Fertilizer
Knowing how often to water houseplants can be difficult. Water your gardenias when the soil is dry to the touch.
Aim to keep the soil evenly moist, if possible. Overwatered plants can develop brown patches on their foliage. Buds may also rot or fail to fully open.
Similarly, under watered plants can also become distressed. The most obvious sign that the plant is under watered is when it sheds foliage.
To check the condition of the soil a soil moisture meter, such as the Atree Soil Moisture Sensor Meter, provides a reliable reading. A less scientific method is to stick your finger in the soil. If the top two inches feel dry, it is time to water. If the top portion of soil is still wet, refrain from watering for a few days.
Remember, during the winter months, when the plant isn’t actively growing it requires less water.
If possible use water that is at room temperature. The easiest way to do this is to draw the water and allow it to stand for a few hours or overnight. Cold water can shock the plant causing damage such as leaf drop.
Instead of tap water, try harvesting rainwater. This is an easy process, all you need is a bucket, and also a cheap way to keep your plants happy and hydrated.
Collecting rainwater is a great way to keep your plants hydrated without running up an expensive water bill. It is also good for the environment and ensures you aren’t adding potentially harmful chemicals to your soil.
Like other houseplants if you want to successfully grow gardenias indoors you will need to fertilize the plant regularly during the growing season. A balanced 15-15-15 general houseplant fertilizer can be used.
Water soluble or liquid plant feeds are easy to apply. Simply dilute the solution to half its recommended strength and incorporate it into your watering routine. Diluting a plant feed helps to prevent over-fertilizing plants. It is easier to correct under-fertilizing than over-fertilization.
When the plant is actively growing, during the spring and summer, fertilize once every two weeks. During the fall and winter, when the plant is dormant, this can be reduced to once a month.
Usually these plants keep a nice, uniform shape with little intervention. However, you may occasionally need to remove stems to shape the plant. A garden scissors is a useful tool if you need to shape or prune a houseplant.
Deadheading and removing woody stems also encourages more flowers to form.
When pruning, be careful not to remove any new stem growth. Gardenia flowers form on new stems. Remove only old and woody stems.
During the winter inspect the plant and remove any dead or damaged stems. This keeps the plant healthy.
If you want to grow more gardenias indoors, propagation is a great way to acquire more plants for free.
To propagate take 2 to 3 inch stem cuttings from healthy stems. This is best done during the spring and summer months when you are pruning the plant. Take the cutting from just below a leaf node. From this node, or bump, new roots will emerge.
Dip the cutting into some rooting hormone. While not necessary this encourages roots to emerge. Following this, place the cutting in a small container filled with an equal mix of peat moss or compost and perlite. Water the soil so that it is moist.
Keep the soil moist until roots have formed. To test whether roots have formed gently try to pull the cutting from the soil. If you feel resistance it is a sign that the plant is developing a root system.
Once the roots have formed, transplant into a larger container and grow on.
Cuttings can also be propagated in water. Simply take the cutting in the manner described above, remove all but the highest leaves and place in a clear vase or glass of fresh water. Change the water on a daily basis. Roots will soon begin to emerge. When the roots are long enough pot the cutting in a container and grow on.
Common Grow Gardenias Indoors Problems
If you grow gardenias indoors, or in high humid environments, the plants can be prone to fungal and bacterial diseases. Ensuring that air can circulate freely around the plant helps to prevent bacterial and fungal diseases from forming. Watering only the base of the plant and early in the morning, so that damp foliage has time to dry, also helps to prevent fungal problems.
Regularly check your plants for signs of infestation. Aphids, whitefly, scale bugs and root nematodes can all target gardenias.
Aphids can be removed by wiping the affected foliage with a solution of soapy water. Apply the solution to both the top and underside of the leaf. Neem oil can also be used. Soapy water or neem oil can also be used to treat infestations of scale bugs, whitefly and mealy bugs.
Spider mites can be removed with an application of neem oil. To check your plants for spider mites, place a sheet of plain paper under the foliage and shake the plant. Fold the paper in half and check for red spots or smears.
Yellowing leaves can indicate a range of issues including overwatering and under watering. Yellowing foliage can also be a sign that the plant is not receiving enough light or that the soil is too wet.
Foliage can also turn yellow and fall from the plant as it ages. This is perfectly natural and nothing to worry about.
Fragrant and attractive it is easy to see why gardenias are such a popular plant. While they commonly grow in flower beds and containers, with a little extra care and attention you will be able to grow gardenias indoors.
Gardenia plants are prized for their attractive flowers, offset by rich green foliage, and beautiful fragrance. A humidity loving plant, it can be difficult to re-create the plants preferred conditions indoors but it is well worth the effort.
Once established a thriving gardenia will reward your efforts with masses of rich foliage and colorful, aromatic flowers. By following the advice in this guide you will find that it is entirely possible to grow gardenias indoors.
Elizabeth learnt to love gardening as a child in her grandparents backyard. Today, she is a trained horticulturist and has maintained a productive allotment for over 10 years. When not growing her own, Elizabeth enjoys helping other people with the plant problems. An experienced writer and editor, away from gardening Elizabeth is also a keen bird watcher, local historian and genealogist, meaning that she can often be found with her dogs exploring an overgrown graveyard.