With their dark glossy leaves and fragrant white flowers, gardenias make a statement in any garden. These evergreen shrubs are commonly found in warm climates throughout Australia, Asia and Africa, lighting up their surroundings wherever they are planted! Gardenias can be grown in pots, in the garden, in greenhouses and even as hedges or groundcovers. The most commonly grown variety is the Florida gardenia, a bushy flowering shrub that reaches heights of up to 1.5m and is ideal to use for hedging. Other popular gardenia varieties include the Magnifica, which grows up to 2.5m in height, the Radicans, which is a dwarf form that works great as a hardy groundcover, and the large flowering Aimee Yoshiba.
Although gardenias are pretty easy to grow and maintain, these plants have a couple of specific environmental requirements to encourage maximum growth and prevent diseases. Here are our tips for keeping your gardenias happy and healthy in Australia.
Temperature & Light
Gardenias prefer warm, sunny weather conditions with mild humidity levels. Although some varieties of gardenia are more tolerant of colder temperatures, frost-free areas with warmer climates are generally much more favourable for these plants. Sydney’s warm summers and mild winters are ideal for growing gardenias. Choose a semi-shaded spot in your garden where your gardenias will receive plenty of natural light and ideally some morning sun without being over-exposed to the hot afternoon sun.
When growing gardenias indoors, it is important to create a suitable environment with bright, indirect light and sufficient humidity. You can use a humidifier to manage humidity levels, although other techniques such as misting the leaves or placing the pot in a tray of rocks over some water will also do the trick. Never allow the plants to sit in water.
Soil
Soil is a crucial consideration when caring for gardenias. Opt for acidic soil that is rich in composted organic matter. Make sure the soil allows sufficient draining to prevent moisture buildup, which can lead to issues such as root rot and fungal diseases. Gardenias also need mulch to help preserve moisture and enhance the overall quality and fertility of the soil. Apply a layer of mulch mixture consisting of organic materials such as manure, compost, tree bark, wood chips or straw to the surface of the soil. Adding a mulch layer around the base of the plant is particularly important during the winter months to protect the roots from colder temperatures. A lightweight and breathable fabric can also be wrapped around the plant to ensure climate protection.
Planting
When planting gardenias in the garden, dig a large planting hole to accommodate the entire root system. Gently untangle the roots before placing the shrub in the ground. After covering the hole with healthy soil as indicated above, create a small well in a ring around the base of the plant to help guide the water into the ground. If you live in an extremely cold climate, your gardenias will be happier when planted in pots since this will allow you to move them to a sheltered location during the winter. When planting gardenias in pots, pay special attention to the quality of the soil. Repot your gardenias once every two years with a fresh potting mix, or more frequently as the plant’s growth requires.
Gardenias can be propagated from cuttings. Take cuttings of about 12cm from the tip of a healthy branch, place them in water and wait for roots to develop before transferring them to the soil. Cuttings can also be grown directly in potting soil. Dip the ends of the cuttings in a rooting hormone before planting them in a potting mix. Once the cuttings have developed independent root systems, they can be repotted or planted in the garden.
Water
Gardenias need plenty of water to thrive, especially during their flowering season from spring to summer. Water one to two times per week depending on the weather and be on the lookout for signs of water deficiency such as yellowing leaves. This can be treated by restoring the plant’s hydration and boosting it with fertiliser. Be careful not to overwater as this can cause problems of its own. In extremely dry conditions, gardenias can benefit from being lightly misted with water to maintain the desired temperatures and humidity.
Maintenance
Gardenias are relatively simple to maintain as long as their light, soil and water needs are taken care of. Pruning your gardenias will help to keep their growth neat and tailored, although this isn’t necessary unless you are trying to grow a hedge or a groundcover of a specific shape. If you would like to prune the shrubs, wait until after the blooming season to remove the older branches without causing damage to any new growth. Gardenias can be boosted with a fertilising agent during spring and summer to maintain the acidity of the soil. You can also opt for DIY solutions such as using coffee grounds to feed the soil around the base of the shrubs.
Spring Colours is a plant nursery located in Sydney’s Dural neighbourhood. With over 30 years of experience in garden landscaping and delivering high-quality plants to plant lovers at great prices, we are committed to making the world a greener place and adding new life to your home and garden.
Contact us to find out about our wholesale service delivery or visit our Nursery in Dural to browse our collection of plants!