Native Gardenia – Australian Native Growing Guide

Introducing the Native Gardenia

The native gardenia, also known as yellow mangosteen, is thought of as a good bush tucker and was used in Aboriginal cuisine. It’s quite a common plant found in coastal forests and beach areas from far North Queensland down through Mackay. 

The plant produces hard-shelled fruits which have a pale, soft and sweet segmented fruit with many small white seeds. They are in fact similar to a mangosteen in size, shape and flavour. The yellow mangosteen fruit can be eaten raw or used in salads, cakes and other desserts.

In springtime, the native gardenia produces white, beautifully fragrant, star-shaped flowers. The flowers later turn into brown fruit that ripens slowly over winter, and then turns yellow when ready for harvesting. 

If the native gardenia is left to grow as a tree, it can reach a height of up to 8 metres and even provide some shade. If you commit to regular pruning, you can keep your native gardenia in a pot or at shrub size.

It makes a wonderful display plant and can be used in tropical gardens and for feature planting, anywhere you can enjoy the beautiful scent.

The native gardenia will do best in a partly shaded position in your garden and prefers warm, moist conditions. You can grow it as far south as Sydney. 

Native gardenias are shrubs or small trees that can grow 4 – 8 metres tall. They have open branches and can spread up to 4 metres wide. They have dark green glossy leaves and plenty of perfumed small white flowers in spring. The lovely flowers attract bees. 

The flowers are then followed by large yellow fruit, up to 10 cm in diameter. They look similar to apples and you can eat them when soft. The fruit ripens in winter and has whitish small seeds.

The leaves are lovely, making the native gardenia a popular small to medium shade tree. 

How to Grow Native Gardenia

Propagation of Native Gardenia

How to Propagate Yellow Mangosteen from Seed

Native gardenia seed can be sown most of the year but is generally best sown in spring or autumn. You want to avoid the coldest and hottest months of the year. The best temperature for germination is between 20-25°C.

You want to sow the seed on a porous seed raising mixture and then cover lightly. Place the container in a warm shaded or semi shaded area so it doesn’t dry out.

The growing medium needs to be well-draining but needs to remain damp between watering. The trick here is to keep it moist but not too wet otherwise the seed may rot.

Do not let the growing mix completely dry out. Germination usually happens in 28-56 days depending on the temperature and conditions. It’s worth keeping seed that does not germinate straight away. 

Seeds will sometimes be dormant until the conditions are closer to what they need for germination to occur. Containers put aside for a while might reveal some sprouts eventually.

Atractocarpus fitzalanii Propagation from Cuttings

When selecting your cutting, it should be at least 12.5 cm long and taken from the tip of the branch. You’re aiming for softwood or green wood cutting. The next step is to remove the lower leaves. 

Take all the leaves off the cutting except for the top two sets. Prepare a pot by filling it with equal parts of peat or potting soil and sand and wet the peat/sand mixture.

Dip the cut end of the native gardenia cutting into a rooting hormone. Create a hole in the mixture and place the cutting in the hole and then backfill. Place the cutting in bright but indirect light and try to keep the temperature around 24°C. The peat or sand mixture needs to stay damp but not soaked. 

The key to propagating native gardenias successfully is making sure the cuttings stay in high humidity until they root. The easiest way to do this is to cover the pot with a clear plastic bag which creates a greenhouse effect.

Just don’t allow the cover to touch the cutting. Regular misting sessions also help the native gardenia to thrive and grow. The plant should be rooted in four to eight weeks. Propagating native gardenias from cuttings is a great way to use up leftover trimmings from pruning. 

No matter how long you’ve been gardening, you can always use some tips and advice. We’ve got a collection of gardening tips to support every gardener, from the beginner, to the green thumb expert.

Check out our tips on everything from soil care to landscaping and everything in-between.

Native Gardenia Care Guide

Fertilising Yellow Mangosteen

Native gardenias are heavy feeders and like lots of iron and magnesium. You can feed your plant every 2 to 3 months from spring to autumn with a dose of cow manure or an organic fertiliser if you don’t have great soil.

For healthy growth and large flowers we also recommend fortnightly feeding with something like seaweed extract. You’ll get amazing results with regular liquid feeding. 

Pruning Native Gardenia

Native gardenias that are grown in enough light will naturally produce a good shape and not need pruning. They can be pruned if you need to reduce their height or keep a certain shape. 

You can prune after a rush of flowers, anytime from late summer into autumn. If you live somewhere with a warm climate, pruning can also be done in winter. 

Soil and Watering for Yellow Mangosteen

Atractocarpus fitzalanii needs a humus rich and moist yet well drained soil. You want to maintain a soil pH of 6-7 for your native gardenia and keep the plant well mulched around the root zone to ensure the soil stays moist and cool.

This plant needs deep, regular watering and might need additional water through dry summer seasons.

Climate and Sunlight Needs

Native gardenias like a tropical, rainforest environment but they can handle warm temperate conditions if they’re in a sheltered and moist position.

Native gardenias like full sun or part shade and can also be grown in containers. Be sure to protect your plant from strong winds.

Native Gardenia as Bush Tucker

Native gardenia fruit can be eaten raw. It can also be used in salads, tarts, jams, cakes and other desserts. The fruit isn’t overly sweet on its own (it has high acidity), but is great when combined with other foods or ingredients and adds a unique richness. 

The actual taste of the fruit varies. Different plants will have different tasting fruit. Fruit that has come from a good native gardenia variety will be large with small seeds, and will taste sweet. The rind is inedible. 

The fruit of the Atractocarpus fitzalanii can be deceiving and tricky to know when it’s ripe. It can be tempting to pick off large, round yellow fruit, thinking it will be perfect and juicy.

You actually need to go for the shrivelled, brown fruits to make the most of the soft flesh inside. When you open a ripe native gardenia, you will see fruit with a thick, brown flesh.

Yellow mangosteens must not be frozen. Refrigeration or freezing quickly causes damage to the fruit. For longer storage, keep it at 10°C which will make it last for several weeks.

If you want to impress your friends with your knowledge of Australian Bush Tucker, why not have a look at our collection of articles. We cover everything from native greens, vegetables and herbs, to medicinal bush tucker. 

Native gardenia Pests and Diseases to Look Out For

Yellow or pale leaves is a common problem with Atractocarpus fitzalanii.  Here are a few reasons why it might happen:

Cold weather – these warm climate plants respond to winter and early spring weather by pulling nutrients out of their older leaves and then dropping them.

Old leaves – leaves have a brief lifespan and yellow mangosteens tend to release old ones together. If you see a whole lot of yellow leaves low on the branches but the rest of the growth is green, your plant is probably doing a shedding. 

Incorrect soil pH – native gardenias like acidic soils.  If they grow in alkaline soils they can’t access all the nutrients they need which causes the yellow leaves.  You can apply sulphur to the soil to make it more acidic.  

Lack of nutrients – if the soil pH is acidic but the native gardenia still looks pale or yellow all over then the plant might just be hungry.  These plants are considered heavy feeders and a lack of nutrition shows quickly.

Specific nutrient deficiency – yellow mangosteens might be lacking a particular nutrient which shows up as yellow/pale leaves with certain patterns. The most common ones are: 

• magnesium – pale/yellow triangular pattern with leaf tips and edges
• iron – pale/yellow leaves but the veins are green
• nitrogen – new growth is pale/yellow

You can treat the plant for the specific deficiency, like using epsom salts for magnesium, but it’s best to first check the soil pH is acidic and then feed with a complete nutrient source.  We recommend some cow manure or an organic fertiliser.

Other than yellowing leaves, there are a few pests to look out for Aphids, scale and mites suck nutrients from the plant and you can spray with neem oil to keep it at bay.

Neem oil kills a wide variety of insects that might affect your native gardenia including aphids, mealybugs, caterpillars, and other garden pests like spider mites.

Sooty mould is a secondary problem caused by sap sucking pests like aphids and scale. Once you manage the pests the sooty mould will dry up and flake away.

If you notice lots of ants on your plant then it means you’re dealing with aphids or mealybug and the ants are feeding on their sugary excretions. If you control the pests, the ants will go away.  You can help the process by applying a border of horticultural glue around the base of plant trunks to limit their movements.

If you start to notice bud drops or flowers failing to open, it’s usually a sign that your plant is stressed. Some bud fall is normal in spring but often your plant is too dry or too wet. You can adjust your watering accordingly. The bud drop can also be caused by pests feeding at the base of the bud and often mealybug is the main culprit.

Native Gardenia FAQs

Where does Atractocarpus fitzalanii get its name?

The genus name is derived from the Greek words 'atractos' meaning spindle and 'karpos' meaning fruit due to the spindle-shaped fruit of the first recorded species.

Fitzalanii was named by Victorian State Botanist Ferdinand von Mueller, who named it in honour of the person who first collected it, Eugene Fitzalan. He was a botanist who created the first botanical garden in Cairns.

Are yellow mangosteens good for you?

Scientific studies suggest that yellow mangosteen has strong antioxidant, anti-cancer, anti-inflammatory, anti-allergic, anti-microbial, and antimalarial properties.

What kind of root system does a native gardenia have?

Native gardenias are considered shallow-rooted shrubs. This means their roots spread out and stay close to the surface, rather than growing deep down into the earth. 

How long can a native gardenia live?

If properly cared for, this plant can live up to 50 years.