I appear to be haunted by mulberry trees and I'm taking it as a sign that I really should plant one. I first encountered the delicious fruit of these trees (which is seldom found in shops due to its very short shelf life) many years ago in Greece. In summer in that country, it is almost impossible to walk along foot paths without standing on the berries which are sometimes as long as your small finger and bursting with bright purple juice. Now, in Iran, where I am currently travelling, I have come across them again in both the white and purple form. The white mulberry fruit is less tasty, with little flavour and just 'sweetness' to recommend it. It's leaves, of course, are the source of food for the silk caterpillars that have made its name famous.
In Iran, purple mulberries stain the ground and make work for the shopkeepers who, every hour or so, must wash down the pavement in front of their premises and sweep the fruit aside. I found a small grove of purple mulberry trees growing in a section of one of Iran's exquisite Persian gardens. Their ripening fruit were as bright as cherries and hidden among the lush foliage which also serves as stock foods and a source of greens for human consumption. One taste of the berries and I determined to find out more about how to grow the trees in New Zealand.
Mulberry trees are in fact quite hardy and will grow in all but the coldest of climates, although they prefer hot summers. They do, however, require cold temperatures to set fruit. Although they prefer a soil with a Ph level of 5.5-7, they are remarkably unfussy. The time to plant them is in winter, bare rooted if you can get them that way. Their roots are rather brittle so care needs to be taken when planting them. When preparing a site, incorporate into the soil plenty of compost and well rotted animal manure and a little blood and bone. This same feeding can be reapplied both before and after fruiting in the coming years. When pruning these large trees, do so only in winter as during non-dormant periods when the sap is rising, 'bleeding' will occur from any wounds.
Mulberry trees are susceptible to wind so they require shelter, especially while getting established. When fruiting, it is important to water them both when the fruit is forming and also when it is maturing. Fail to do this and the fruit will begin to drop before it has ripened. For those like me who live in a possum and kereru zone, the only way to protect the fruit is to cover it so aim to have either a very large cage in which to enclose the tree or prune to espalier so the berries can be easily protected with netting.
Is it worth all the work? I'd have to say that the taste of the berries and the sight of them hanging in the tree like Christmas baubles is enough for me to say, without reservation, YES! Now to set about sourcing one on my return home. If you are looking for a mulberry for your own property, try Incredible Edibles at edible.co.nz