Why Are Gardenias So Hard To Grow? 7 Reasons

Gardenias are notoriously challenging to grow, but due to their beauty and fragrant aroma, they are a popular garden addition. There are many reasons your gardenias might be struggling, and where you live plays a huge part in that. So why exactly are gardenias so tricky to grow? 

Gardenias are hard to grow because they require particular care, such as 4 – 6 hours of sunlight per day, mild temperatures, regular watering, and proper pest control. Gardenias grow best in gardening zones 8-11 and need partial shade on hot days. 

In the rest of this article, I will go over the 7 reasons why gardenias are so difficult for most people to grow and some tips for combating these issues. So if you would like to learn more about how to grow gardenias successfully, be sure to read on. 

Reasons Why Gardenias Are So Hard To Grow

Gardenias originated in Southern China and thrive in similar climates. These fragrant plants have gained popularity worldwide, and many gardeners have successfully grown these plants. However, there are certainly a few factors to consider when growing gardenias.

Gardenias are so difficult to grow primarily due to their temperature needs. These plants prefer full sun but will quickly die if they become too warm or cold. This is a reason many opt to grow their gardenias in a greenhouse where the temperature can more easily be managed.

These plants also require plenty of water but not too much water, or they will develop root rot. So as you can see, gardenias are pretty picky and require a lot of care and maintenance. However, there are many ways to combat these issues. But, first, let’s talk about the 7 reasons why your gardenias are probably struggling. 

1. Lack of Sunlight

The main reason gardenias are so difficult to grow is their preference for full sun while still needing to maintain a mild overall temperature. Gardenias need at least 4 hours of direct sunlight per day. However, if you want your plant to thrive, it’s recommended that they get about 6 hours. 

Generally, your gardenia plant should be placed somewhere that experiences full sun (typically in the morning) and partial shade during the hottest part of the day. It can be challenging to balance this plant’s need for light against its temperature constraints, but it’s certainly possible. 

2. Improper Temperatures 

The next most common cause of death in gardenias is improper temperatures. These plants are incredibly picky when it comes to the conditions under which they will grow. As a result, they are highly susceptible to stress and prefer mild temperatures.

Gardenias’ ideal growing temperatures are 65 – 70°F (18 – 21°C) during the daytime and nothing below 60 °F (15 °C) at night. These exact temperatures can be challenging to maintain when your gardenias are planted outdoors. An unanticipated cold or warm front can easily kill your plants.

3. Humidity Issues 

Another primary reason that gardenias struggle is incorrect humidity. Gardenias need above 60% humidity to thrive. This is a relatively high amount of humidity which can be difficult to replicate if you live in a dry climate. However, growing these plants in a greenhouse can aid in maintaining the correct levels of humidity. 

4. Inadequate Soil

Poor soil quality is a significant factor in your gardenia’s overall health. After all, plants draw most of their nutrients from the soil they grow in. So what makes soil inadequate for your precious gardenias? 

The two main factors that make soil inadequate for gardenia use are poor drainage and lack of nutrients. Unfortunately, both of these factors have a massive impact on the health of your plants. 

When your gardenias are planted on a substrate with poor drainage, the soil will become oversaturated with water. This results in your plant’s roots sitting in a stagnant pool of water and eventually developing root rot. 

Lack of nutrients in the soil can occur due to the following:

  • Poor soil quality in your area.
  • The soil has been previously used to grow other plants. 
  • New soil or compost has never been mixed in. 

Plants like corn quickly deplete soil nutrient resources, and when you plant things like gardenias in their place, there is a good chance that the vitamins and minerals in the soil have been depleted. So it’s always a good idea to add in some fresh new soil if you have nutrient concerns. 

5. Garden Pests 

Gardenias seem to be a magnet for garden pests, specifically the white fly and aphids. Sadly, these bugs can quickly ruin the flower and leaves of your plant. Unfortunately, each pest comes with its own horrible consequences. 

The most common pests you will encounter on gardenias are:

  • Whiteflies: Whiteflies lay eggs on the undersides of gardenia plants and suck sap from the leaves damaging the plant in the process. 
  • Aphids: These little pests damage your plant by piercing it and sucking out the juice from the gardenia. This can result in several problems for your plants, such as reduced growth. Not to mention that aphids can transmit deadly plant viruses. 
  • Twospotted spider mites: These blob-like pests or spider mites will quickly spread and cause the plant to look ill with its black moldy bodies. 
  • Wax scale: These pests suck nutrients from their host, resulting in blackened leaves and even death with large-scale infestations from wax scales

These are just a few of the more common pests that could be affecting your gardenia’s growth. 

6. Overwatering 

Another common reason gardenias are so difficult to grow is their watering needs. Gardenias need plenty of water but can easily fall prey to overwatering. Ideally, gardenias should get about 1 inch (25 mm) of water per week. 

However, depending on how well the soil drains, you can easily end up overwatering. So it’s important to always check the soil moisture levels before watering.  

7. Improper Pruning 

Lastly, your gardenias might not be thriving due to improper pruning. Gardenias need to be pruned to grow their best and produce lots of fragrant flowers. However, it’s important to note that these plants should never be pruned while flowering. Instead, it’s best to prune gardenias when they are dormant. 

Tips for Growing Gardenias More Easily

If you are confident that one or several of these factors is affecting your gardenia plants, don’t fret. There are ways to combat each common reason gardenias struggle to grow. So let’s dive right in and learn a few tips for growing gardenias easily. 

Gardenia growing tips:

  • Choose the best location. Location truly matters when planting your gardenias. Gardenias are vulnerable plants, and they require plenty of sunlight to grow. An area with bright morning sun and some relief from the afternoon sun is ideal when growing these plants. 
  • Monitor outside temperatures. Gardenias prefer mild climates and are susceptible to both extreme heat and cold. So it’s essential to act quickly if you notice a hot or cold front moving in. A great way to control the temperature is by planting your gardenias in a greenhouse. 
  • Add nutrients to the soil. The best way to do this is by adding compost or an excellent fertilizer to the soil, such as Miracle Gro Potting Mix.
  • Provide adequate humidity. As previously stated, gardenias need high humidity levels. You should monitor this carefully and do your best to mist these plants on dry days or plant them in a greenhouse where humidity can more easily be controlled.
  • Use pest deterrents. A mild pest deterrent like apple cider vinegar or insecticidal soap can aid in keeping your plants safe from harmful pests. 
  • Create a watering schedule. Sticking to a schedule will ensure that your gardenias don’t become overwatered. You should still always check the soil’s moisture levels before watering, just in case. 
  • Prune gardenias when they are dormant. Pruning these plants is necessary as it allows for much-needed nutrients to focus on healthy flowers and leaves. Plus, it will leave your plant looking much nicer when it blooms. 

As you can see, there are few ways to combat the most common concerns when it comes to growing gardenias. These plants are incredibly fragile and must be regularly monitored to grow successfully outside their ideal climates. 

Suppose you would like to learn a little more about growing gardenias. In that case, I recommend watching HortTube with Jim Putnam’s video on the different varieties of gardenias and how to grow them. 

Final Thoughts

Gardenias are pretty tricky to grow. However, you will have a much better shot at getting these stunning plants to grow if you do your research. These plants are incredibly fragrant and beautiful, making them a coveted addition to any garden. 

When attempting to grow these plants, just remember: 

  • They need 4 – 6 hours of direct sunlight. 
  • They prefer temperatures of 65 – 70 °F (18 – 21 °C).
  • They need above 60% humidity. 
  • They need nutrient-rich soil.
  • They need plenty of water, but you should never overwater. 

Alexander Picot

Alexander Picot is the principal creator of TheGrowingLeaf.com, a website dedicated to gardening tips. Inspired by his mother’s love of gardening, Alex has a passion for taking care of plants and turning backyards into feel-good places and loves to share his experience with the rest of the world.

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