The Yuko is a lesser-known citrus fruit native to Japan and extremely rare in Europe. The trees resemble the more common yuzu, with only subtle differences to the leaf shape. The rind of the ripened fruit has a sweet scent similar to pomelo and yuzu.
Although the origin on this species is not totally clear, it is understood that the Yuko came about due to natural crossbreeding. In the right conditions this tree can grow to up to 18 feet tall, but it is much more common for the trees to reach 6 to 8 feet.
The trees are suitable for growing in pots indoors or out, they can also be planted into the garden two years after purchase. They are expected to flower the spring after purchase and within two years will hold fruit to harvest if conditions allow. Rapid and extreme changes in temperatures can cause flowers and fruit to fall early. Fruits ripen throughout the year ready for harvest during October – December. All trees stand 100-120cm tall (including pot)
To establish the tree, grow in a pot for the first two years and move to protected spot over winter to protect it from frost. Trees can then be planted out during the spring growing season. They should still be protected from frost for a further 3 years. After that, they will tolerate temperatures down to -7ºC. They will tolerate alkaline soils but thrive in acidic conditions.
Outdoors a sunny, south-facing, sheltered spot is desirable. Acidic soils are preferable, clay soils should be mixed with sand to allow for good drainage and mounding the earth above the soil level is recommended in these conditions. In dry conditions once or twice weekly watering is preferable to little and often. Waterlogging is the most common ailment in the UK climate so please follow the drainage advice above and prevent the tree sitting in water.
In containers use free-draining compost, additional perlite or hardwood bark will improve drainage if the compost does not already contain these. Irrigation should be controlled so the plant is well watered and allowed to dry out, rather than kept permanently moist. Re-pot every 1-2 years increasing the size of the pot each time by 20-30%. Raise the base of the pot above the surrounding ground to allow for free drainage of any excess water. If you choose to keep your pot outside some of the year and move in for winter, remember to use a light pot so you can lift it.