Satsuma: profile, growing & care

Verena
Verena
Verena
Verena

I grew up on a small, organic family farm and after a gap year spent working on an American ranch, I started studying agricultural science. Soil, organic farming practices, and plant science are what I am most drawn to. At home, when I'm not in our garden, you can find me in the kitchen, cooking and baking with our harvested fruits and vegetables.

Favorite fruit: Even if a bit boring - apples
Favorite vegetables: Bell peppers, red beets, zucchini, white cabbage

Fresh satsumas right from your own garden? It is possible, and it does not take an expert or much space.

orange satsuma fruits on tree
The satsuma forms tasty fruits with little to no seeds [Photo: AlenKadr/ Shutterstock.com]

Anyone planning on buying a citrus tree should definitely consider a satsuma (Citrus reticula subsp. unshiu). Unlike clementines and tangerines, satsumas have a higher cold tolerance and almost always bear seedless fruits.

Satsuma: origin and characteristics

Satsumas, sometimes called satsuma mandarins or satsuma oranges, likely originated in Japan, where, according to the latest findings, there was an accidental crossing and then backcrossing of two mandarin varieties. Because of these findings, satsuma is no longer classified as a separate species (Citrus unshiu), but rather as a variety of the mandarin (Citrus reticula). Satsuma are grown in subtropical regions all over the world, with the largest cultivation area still in Japan.

This evergreen tree has very few thorns and remains relatively short throughout its life. When grown in pots, a satsuma can reach a maximum height of about two metres. The abundant, small, white flowers that appear in spring are particularly beautiful to look at. From these develop the orange fruits of the satsuma which are harvested from October onwards. It is not uncommon for green satsuma fruits to be fully ripe despite their peel colour. When the fruit is ripe, the peel often softens and separates slightly from the flesh of the fruit.

white flowers on satsuma tree
In spring, satsuma trees are especially charming with their delicate white blossoms [Photo: Tana Dan84/ Shutterstock.com]

Do satsumas have seeds?

The vast majority of satsumas do not have seeds because the fruits can also develop from unpollinated flowers. Although rare, it is possible to find a little green seed in one of the segments.

Satsumas vs. clementines

At first glance, there is no difference between satsumas, tangerines and clementines. But on closer inspection, just as there are many differences between clementines and mandarins, satsumas also stand out from the other two. Unlike tangerines, for example, satsumas are essentially seedless. Satsumas differ from clementines in that they are a bit larger, sweeter, and have a thinner skin. In addition, they often still have green skin when they are already ripe for eating.

dark orange peels of tangerines
Tangerines have a slightly darker peel than satsumas [Photo: Picmin/ Shutterstock.com]

Growing satsumas

Satsumas should only be grown in pots. Although they are relatively cold-tolerant for citrus fruits and can endure short frosts, they should not be exposed to too much winter cold. When planning to grow your own satsuma, check out our information on other citrus fruits to guide your choices for soil and location. For example, our peat-free Plantura Organic All Purpose Compost makes an ideal substrate for your satsuma − just mix in one-sixth sand and one-sixth granulated clay. You can also use a high-quality citrus soil that meets these requirements. The disadvantage of ready-mixed citrus soil, however, is that it often contains peat that is harmful to the climate.

Plantura Organic All Purpose Compost
Plantura Organic All Purpose Compost

Peat-free & environmentally-friendly:
for all house & garden plants,
100% natural ingredients,
child & pet friendly

At a glance: Planting satsuma

  • Grow in a pot with well-draining, moderately nutritious substrate
  • Location: summer – warm, sunny spot sheltered from the wind; winter – bright area that does not get too cold (5 to 10 °C)
  • Repot your satsuma tree every 2 to 3 years in April
bunch of green satsuma fruits
Even small satsuma trees bear a lot of fruit [Photo: Picmin/ Shutterstock.com]

Satsuma tree care

When it comes to care, most citrus trees are very similar. In general, satsuma trees need a lot of water, but they do not tolerate waterlogging at all. So, water regularly but cautiously, making sure that excess water can drain away.

Pruning the satsuma is not necessary, but it can be done in early spring to shape it.

Satsumas grown in pots are reliant on the gardener for their supply of nutrients. Our animal-free Plantura Liquid Citrus Food provides your plants with everything they need. In addition to nitrogen and potassium, this also includes iron in an accessible form to prevent iron deficiency, which is a common problem in satsumas and other citrus plants.

Plantura Liquid Citrus Food
Plantura Liquid Citrus Food

Liquid fertiliser with an NK ratio of 4-5, for all citrus & Mediterranean plants, promotes healthy plant growth, child & pet friendly

Tip: Did you know that our Liquid Citrus Food contains almost no phosphorus, even though it is an essential plant nutrient? This is because we are concerned about conserving the world’s scarce phosphorus resources for sustainability. The phosphorus requirements of your citrus plants are covered by the potting compost, which is replenished through repotting every two or three years. If for some reason you are unable to repot your satsuma, we recommend fertilising once a year with a fertiliser that contains phosphorus, such as our Plantura Flower Food.

Are satsumas hardy?

Even though they are cold-tolerant as far as citrus trees go, and full-grown satsumas can even tolerate short frosts down to – 8 °C, satsumas are not considered hardy. Therefore, it is best to bring your satsuma tree indoors for overwintering. You can follow the procedure for overwintering lemon trees. Overwintering a satsuma tree is easiest in a bright and cool place at around 10 °C. When the temperatures warm up again around May, the satsuma can be put outside. But beware, freshly overwintered young trees are still particularly vulnerable to late-spring frosts.

two satsuma fruits on tree
Even indoors, the fruits of the satsuma tree have no trouble ripening [Photo: Picmin/ Shutterstock.com]

Harvest and taste

If you have your own satsuma tree, you can harvest the first fruits beginning in October. But do not worry, even once the tree has been brought indoors, the fruits will still ripen. You will be able to harvest satsumas for much of the winter. Satsumas taste very similar to tangerines but are sweeter and milder. Satsumas are smaller than tangerines and contain up to 35 to 50 kcal per fruit.

When are satsumas in season? Satsumas are ready for harvesting in late autumn. In the northern hemisphere, they are in season from October onwards.

orange insides of green satsumas
Green satsumas are often edible because the fruit inside is usually already ripe [Photo: Trialist/ Shutterstock.com]

A nectarine tree also brings a southern flair to your garden. In a sunny, sheltered spot, it can even be cultivated outside all year round in certain regions.

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