Originating from Japan, Satsuma trees are types of mandarin orange trees and produce nearly seedless, miniature oranges. Satsuma citrus trees grow best in tropical or subtropical regions that experience few, if any, freezing temperatures or frosts during winter. Satsumas bear fruits with bright reddish-orange peels and typically grow to only a small-sized tree. Routine Satsuma orange tree care involves mainly fertilizing and irrigating the tree, because Satsumas don't require any special training or pruning to develop a healthy form.
Water your newly-planted Satsuma tree deeply to thoroughly soak the soil down to and around the root ball once every two or three days during the first week after planting it. Gradually decrease the watering frequency to once every seven to 10 days during the first three to four months.
Water your established Satsuma orange tree slowly and deeply once every two weeks to soak the soil around the roots. If you have very sandy soil, divide your waterings in half to once every week.
Feed your newly-planted Satsuma orange tree only after new growth emerges on the tree. Provide 1 cup of ammonium sulfate or a 21-0-0 NPK formula fertilizer divided into three or four separate applications during the first year. Spread the fertilizer granules on the ground over the root area around the Satsuma tree and water generously.
Feed your established Satsuma once in February, once in May and again in September with ammonium sulfate. Provide 1 cup of ammonium sulfate for each year of tree age, divided into the three separate applications.
Keep weeds and grass at least 12 inches away from your Satsuma orange tree's trunk by shallowly hoeing them. You may also apply an appropriate herbicide to control weeds around the tree.
Protect your Satsuma orange tree from freezing temperatures and frosts, especially when the tree is young or newly-planted. Drape a blanket or tarp over the tree when cold weather threatens, securing the covering to the ground with stakes, rocks or other tie-downs.
Harvest the Satsuma oranges as soon as or right before they achieve their ripe peel color. You can even harvest the Satsumas when their peels are still slightly greenish. Satsuma oranges will become "ricey" or "mealy" if they're left on the tree too long after ripening.