There’s no doubt that backyard gardeners in Australia have a love affair with growing citrus trees.
If you already have a lemon tree, why not consider growing your own mandarins?
In this post, we tell you exactly how it’s done.
How to plant a mandarin tree
Like most citrus trees, mandarin trees prefer to grow in full sun in well-drained soil.
You can purchase a variety of different mandarin trees at your local garden centre or nursery.
Once you get the tree home, here’s how to plant it:
- Choose a sunny spot. Mandarins like to be grown in full sun in order to produce lots of lovely sweet fruit.
- Enrich the soil. Mandarins prefer well-drained soil that’s been enriched with organic matter. You can either add your own compost or dig in some Dynamic Lifter. If the soil is on the clay side, consider adding some gypsum and digging it in.
- Dig your planting hole. The hole should be as deep as the rootball of the plant and twice as wide.
- Remove the mandarin tree from the pot. Carefully tease out some of the lower roots and trim off any roots that are circling or have become overly tangled. You want to be able to spread the roots out as much as possible as you place the tree in the hole.
- Plant the tree and backfill. After you place the tree in the planting hole, backfill and firm the soil down gently. Mound the soil around the base of the tree slightly.
- Create a circular well around the edge of the planting hole. This will hold the water and ensure that it gets down to the roots.
- Water well. This will help to settle the soil around the roots.
- Mulch your tree. Place a thick layer of mulch around the base of the tree out to the drip line. This will keep the soil cooler and help to retain moisture.
- Keep your young tree well-watered. While the tree is still young, you want to ensure that you water it once or twice a week if there has been no rainfall.
How to grow mandarin from seed
It’s entirely possible to grow a mandarin tree from seed but you’ll have to be patient because it can take up to 5 years for the tree to start producing fruit.
Bear in mind that most mandarin trees available at nurseries are grafted and seeds from these won’t grow true to form.
If you do want to grow a mandarin tree from seed, choose the Emperor variety.
The seeds from this variety will grow true to form and you’ll get fruit sooner.
Here’s how to grow a mandarin tree from seed:
1. Collect seeds and plant in a seed-raising mix
- Collect the seeds from an Emperor mandarin.
- Wash the seeds gently and dry them on a paper towel.
- Plant the seeds into a tray or small pot filled with a seed-raising mix about 5mm deep.
- You can plant all the seeds in one tray or plant one seed per pot if you’re using small pots (10 cm).
Note: Mandarin seeds are best planted in spring or early summer. If you’ve collected seeds at other times of the year, you can store them in an envelope, paper bag, or airtight container. Keep in mind that fresh seeds have the best germination rates, so don’t store them too long.
2. Caring for your seeds and seedlings
- After sowing the seeds, water well.
- Place the seeds in a warm spot. If you have a mini glasshouse, this is perfect. Otherwise, you can create your own clouche by cutting off the bottom of a soft drink bottle and placing this over the soil in the pot.
- Pots with mandarin seeds should be kept in a bright spot but out of direct sunlight.
- Keep the seed-raising mix moist until you see the seeds start to germinate. This should take around 7 to 10 days.
- Once the tiny seedlings are around 5cm high, apply a diluted liquid fertiliser every 14 days.
3. Transport the seedlings outside
- You can now remove the clouche and place the pots outside as long as the weather is warm. Put them in a sheltered but sunny spot and keep them well-watered.
- When the seedlings are around 15 cm tall, you can repot them into a larger pot with a diameter of 15 cm.
- Continue to repot your small mandarin trees into larger pots for around 2 years.
- When the small trees have reached a height of around 30 cm, they can be planted into the garden.
Caring for a mandarin tree
Mandarin trees are fairly low-maintenance once they become established in the garden.
They just need adequate water, regular fertilising, and a little pruning.
- Water deeply once a week during periods of dry weather.
- Feed with a slow-release fertiliser like Dynamic Lifter 3 times a year in spring, summer, and autumn.
- Once the tree starts to flower, you can apply a liquid citrus fertiliser once a week to stimulate good fruit production.
Pruning mandarin trees
Mandarin trees should be pruned in winter while they are dormant and after all the fruit has been harvested.
Here are some tips:
- Prune off any low branches that are closer than 30 to 45 cm to the ground and remove any suckers.
- Make sure that you remove any branches that are growing from below the graft.
- Remove crossing and inward-growing branches from inside the canopy to open up the interior of the tree like an open umbrella.
- Make sure that you cut the branches as close to the trunk as possible at a 45-degree angle.
Growing mandarin trees in pots
Here’s how to grow a mandarin tree successfully in a pot:
- Choose a pot that is at least 60 cm in diameter with adequate drainage holes.
- Fill with good quality potting mix and add a little Dynamic Lifter or other slow-release fertiliser.
- Place the tree into the pot and backfill.
- Water well and keep watering the tree two or three times a week.
- Place the tree in a nice sunny spot.
- Feed with a slow-release fertiliser in spring, summer, and autumn.
- When flower buds start to form, feed with a liquid citrus food once a week.
Varieties of mandarin trees
The most common mandarin varieties available for home gardeners include:
- Robbie Engall Seedless
- Thorny Mandarin
- Honey Murcott
- Japanese Seedless
When do mandarin trees fruit in Australia?
Mandarin trees fruit in summer but ripening can happen throughout autumn and winter.
When do mandarin trees flower in Australia?
Mandarin trees flower in spring. The flowers are white with a citrus fragrance.
How long does it take to grow a mandarin tree?
It can take up to 5 years before your mandarin tree will start to produce a decent amount of fruit but you should see a little fruit production in its 3rd year of growth. However, if you’ve purchased a grafted tree, you might see some fruit in the 2nd year because most grafted varieties use 2-year-old rootstock.
Do mandarins ripen off the tree?
Mandarins don’t ripen once they’ve been harvested so it’s best to wait until they are ripe before picking them.
Why are my mandarin tree leaves curling?
Citrus leaves can curl for a number of reasons. These include over or under watering, a pest infestation such as mealy bugs, scale or mites, or in response to extremes in temperature.