Four Seasons mulberry is a unique cultivar that is able to produce fruits from May and into December in Sacramento Valley. I suspect it is evergreen and producing year around in the tropical conditions. The first wave of fruits is never as sweet as the fruits from July and later in the season. They are sweet and complex when ripening in hot weather. They also have some pleasant acidity. The fruits are large and black. The tree is small, and it grows like a bush, branching low at the base. The branches are slender and the leaves are small.
Two photos below are from May
And the last picture shows how the fruits of this cultivar compare in the size and shape with othe mulberry cultivars. This picture is from June.