Q.My Jasmine Grand duke refuses to flower.
I have a Jasmine Sambac- Grand duke plant that I had for almost 40 years. It flowered a little in the beginning, intermittently, with a few flowers through the years. It grows well, lot of leaves and vine. I had cut it back a bit, hoping it will stimulate flower growth. It did not. I gave it flowering food …nothing. All the other Jasmine plants are happily flowering all year round. Nothing on the grand duke. I gave it epsom salt. Nothing. This year, I even took a whole pot of plant and out it in the ground late spring.This is one of the big pot I had rooted from the mother plant. Still nothing. Can the plant go sterile (for the lack of description). It is a healthy plant. It does get spider mites in the winter when it is indoor, which I wash with mild soapy water. It is happy outside in the summer. Just not flowering. I saw on youtube, people grow them as bushes in CA and India, I am in MD, so I thought I would try it in the ground staring spring. Still nothing. It is mid July now. I can be reach at lchang@mail.nih.gov. Many thanks. Lisa Chang

This article will help you with a jasmine plant that refuses to flower: https://www.gardeningknowhow.com/ornamental/flowers/jasmine/non-flowering-jasmine.htm