The article you are about to read is all about how to grow gardenias and gardenia bush care. Gardenia bush is a woody perennial shrub that grows in USDA plant hardiness zones 8 through 11.
This attractive evergreen small to medium shrub produces fragrant and beautiful creamy flowers from late spring to late autumn. It is a love to many gardeners with its flowers symbolizing gentleness, purity, secret love and, joy.
Many gardeners have also used this versatile shrub as hedges as well as a background planting. So, as you can see apart from its beauty and fragrance there are other ways to use gardenias.
In this article, you will learn tips on how to grow and care for gardenia bush from site selection, cultural requirements as well as common physiological problems in gardenia bush care.
Let’s get into it then!
How to Grow Gardenias - Step by Step
1. Select a suitable soil/potting mix to grow your gardenias
Gardenias like moist, well-drained nutrient-rich acidic soil (soil pH between 5.0 and 6.0). Add plenty of manure or organic matter like peat moss to the soil to improve drainage and enhance plant growth.
If you grow your gardenias in pots/ containers, use a growing media that contains one-part sterilized houseplant potting medium, two parts peat moss, and one-part perlite or sand.
2. Sun or shade for your gardenias?
A site with full sun or light shade is perfect for growing gardenias. In a cooler climate, gardenias perform best in the full sun especially when you cover their roots with organic mulch.
On the other hand, in a hot or tropical climate, gardenias prefer some shade particularly from the full summer heat therefore, expose them to some shade during the warmer months to avoid leaf scorch and bud fall due to too much sunlight.
Moreover, container-grown gardenias need a bright light or filtered shade but not direct sun therefore, expose your indoor gardenias to at least 6 to 8 hours of direct sunlight through a sunny window.
3. Propagate your gardenia plants appropriately and at the right time
Gardenia bush is a simple to propagate and grow shrub. Just cut off a branch from your gardenia plant in mid-summer and strip off a few lower leaves and blooms if any.
Then stick the branch in a bottle of water (or use a rooting hormone) and allow the roots to grow. Within a month, your cutting will be ready for planting.
4. Plant your gardenias at the right time
The best time to plant gardenia shrub is in spring or fall but, before you plant your gardenias, you first need to amend the soil with bark or organic compost to improve drainage.
Then dig wide planting holes to give your plants enough room for roots to spread so that there will be minimal or no root disturbance after planting.
Outdoor gardenias thrive best in raised beds where you can make alterations easily for better drainage. As for your potted gardenias, make sure the planting pots/ containers drain well so that the soil/ potting mix is not soggy.
5. Water and mulch your gardenias
Gardenias need regular and consistent watering with at least an inch of water a week (from a hose or rainfall) otherwise, your garden leaves and buds will start to drop off.
You also need to apply at least 2 to 4 inches of mulch to control weeds and also to maintain moisture in the soil.
Pro Tip: Do not let the soil to completely dry before you water your gardenias
6. Fertilize your gardenia
Fertilize your gardenias with a diluted fertilizer for acid-loving plants once or twice at max from March to October (growing season) You can also look for fertilizers with additional copper of iron as these enhance flower and leaf development in gardenia bush.
Do not fertilize your gardenias when dormant (during fall or winter), as this will be just a waste of your time and resources
7. Deadhead your gardenias
Gardenias usually drop their spent flowers therefore deadheading (removing the spent flowers) will only be necessary if you want to improve your gardenias' appearance.
Cut back the flowering stem to a set of leaves anywhere on the stem. Wherever you cut back a spent flower stalk, you create room for more stems to emerge and you end up with bushier/ fuller plants. This is also a good way to keep your gardening blooming for long.
8. Rejuvenate your gardenias by pruning at the right time
The best time to prune your gardenias is in the summer just right after the blooms have faded away.
Since gardenias set their flower buds for the next year in the fall, pruning in the summer allows you to cut back some of the older wood without the risk of cutting away the newly set buds.
Pruning also helps to make your gardenia bushy and attractive.
Pro Tip: Always use sterilized pruning shears to protect your gardenias from infections.
9. Protect your gardenia bush from winter
Gardenias do not like cold temperatures therefore, as the weather cools down you need to protect your gardenia plants and roots from cold.
10. Mix coffee grounds in the soil
Coffee grounds are rich in magnesium, nitrogen, and potassium so you can at times use them as homemade gardenia fertilizer.
They are also very acidic thus, lowers the soil ph and stimulates the roots for good performing gardenias.
11. Apply vinegar to the soil/growing media
Whether you grow your gardenias indoors or outdoors, they perform best in acidic soils as they can get the nutrients they so much need. When the soil is more alkaline, your gardenias don’t get the amount of iron they need.
That’s why your gardenia leaves may turn yellow with prominent green veins and stunted growth.
Although it’s a short term solution, applying vinegar (5 percent acetic acid) to the soil will lower the soil pH to a level that’s favorable for your gardenias.
Vinegar is also an effective weed killer so you find fewer weeds around your gardenias. It also deters insects like ants and slugs from getting to your gardenias.
12. Make use of Eggshells for your gardenias
Eggshells contain calcium carbonate which is essential for the healthy cell walls of your gardenias.
Till the eggshells in the soil during fall because it takes several months for them to be broken down for absorption by the plants. You can still add more eggshells in spring if need be.
Another advantage of using eggshells on your gardenias is that their sharp-edges help to keep out snails and improves soil aeration. Make sure to rinse the shells so that they don't attract bugs which would defeat the intended purpose.
Caution: Eggshells reduce the acidity of your soil therefore, use them wisely so as not to negatively affect your gardenias.
13. Use Epsom salts in gardenias
Gardenia bush loves lots of magnesium and when there is a shortage of magnesium available for the plants, the older leaves start to turn yellow before the right time. You can boost your gardenia flower blooming and maybe bring back some green to the yellow leaves by applying Epsom salt.
Prepare a solution of Epsom salt and water (half a litre of water + half a teaspoon of Epsom salts). Mix well to ensure that the salt dissolves completely then water it on your gardenias or apply the solution as a foliar spray once or twice a month.
14. Indoor/ potted gardenia bush care
Gardenias thrive best in humidity and heat therefore, when you grow gardenia indoors ensure to place them in bright – indirect light (not direct sunlight).
To give your gardenias the natural humidity that they love, place your potted gardenias near a humidifier or in a tray of rocks with some water underneath. Alternatively, use a mister to get the desired humidity levels.
You also need to remember that although gardenias love moisture, they hate to be left in standing water, hence make sure to use well draining pots/ containers for your plants.
15. Common Physiological Problems in Gardenia Bush Care
Gardenia buds falling off/ dropping
When your gardenias drop buds just before they open, it could be an indication that your plants aren’t getting enough humidity as they should.
Additionally, gardenia buds dropping can also be caused by poor drainage, over/under watering, low light levels and, over-fertilizing. Moreover, gardenias drop their buds when you suddenly expose them to short periods of cold.
Brown gardenia leaves
Gardenia bush doesn’t like its leaves wet, therefore, water your gardenias properly at the base and ensure that the leaves don’t get soaked.
Other reasons why your gardenia leaves turn brown include; inadequate soil drainage, changes in soil pH as well as powdery mildew (if the leaves have a powdery substance)
Gardenia not blooming
Is it time for your gardenia to bloom and it hasn’t? Well, there are several reasons why there are no blooms in your garden. One of these reasons is improper pruning during the previous season.
Gardenias start to bud early for the next year therefore, do not wait until August to prune your gardenias as this might hurt the main blooms the following summer.
If you haven’t pruned your gardenia but still no blooms, you might need to do a soil test and determine whether the soil conditions are right.
As you do all this, pay attention to drainage, temperature, humidity and, light as they also affect how your gardenias bloom.
Yellow gardenia leaves
Bad watering habits accompanied with poor soil drainage can result in root rot which then leads to yellow leaves in gardenias. Over time, the leaves fall off the plant.
Other causes of yellow leaves on gardenia bush plant are; low light levels and, deficiencies in the soil (a soil test is necessary)
Black buds and drooping leaves in gardenia
Black buds in your gardenia? The main reason why your gardenia has black buds could be exposed to hot and dry weather.
Under hot and dry weather conditions, your gardenia is not able to absorb water as quickly as it should for a healthier plant. It rather loses more water through the leaves and who suffers the most? The buds and the leaves.
16. Protect your gardenias from pests and diseases
Common pests in gardenia bush plant
These soft little-bodied insects usually cluster underneath the gardenia leaves and around the new growth. They cause damage to the plant by sucking sap and in severe cases, they can cause plants’ death.
Whiteflies cause similar damages as those caused by aphids. The infected plants become stunted, leaves turn yellow, and eventually die. These insects also excrete honeydew which encourages the growth of sooty mold fungi.
Apply insecticidal soap sprays to control whiteflies on your gardenias.
Common diseases in gardenia bush plant
Powdery mildew in gardenias appears as a white, fuzzy, or powdery coating on the leaves as well as deformation of new growth. This disease is caused by poor air circulation that leads to humidity build up around the plants which encourages germination of mildew spores.
To control powdery mildew in gardenias, thin out the plants to improve air circulation or move your potted gardenias away from other plants and structures.
You should also consider using neem oil for effective control of powdery mildew
Overwatering and poor drainage in gardenias often lead to root damage by fungal pathogens. After some time, your gardenias turn mushy, black, or brown leading to a gradual or widespread wilting depending on how severe the infection is.
Control root rots in gardenias by proper watering and save the infected plants by uprooting and pruning away the damaged roots then replant them in a site with good drainage.
Let me wrap this up by mentioning that with the actionable tips on how to grow gardenias discussed in this article, caring for your gardenia bush will be an an exciting experience .
Put the information you now have on gardenias into practice and enjoy the beauty and sweet fragrance that comes with the hard work.
In case you have questions, clarification, or additions to this article, please feel free to comment below.