Yellowing Star Jasmine
About a week ago, I purchased two potted star jasmine trellises to form a barrier on the deck. One of the pots is thriving, and the other is not. The nursery assured me that I did not have to re-pot these for a couple of years. When we got them home, I watered them through and fed them with a good fertilizer that was recommended to me. It has been pretty hot down here, so I have watered them through every other day. I am not sure what to do next. We are going away and will have people in the house for a month. I have the whole porch on a drip system, but I was wondering if there is something else I need to do to make sure the jasmine on the left stays healthy. The jasmine on the left does not get as much shade as the one on the right...
Star Jasmine is actually not a true jasmine, but Trachelospermum jasminoides. It is not considered hardy (i.e. able to withstand frost) in our climate. It also requires a shady location to thrive in our hot summers. It is unfortunate that a local nursery did not warn you of these facts. Given shady conditions to avoid leaf scorch, the plant grows well in many parts of the Central Valley in California as welll as other more southerly locations.. It is not surprising therefore, that hot sunlight directly on the plant, as you have noticed, does some damage.Coming from a protected spot in a nursery or greenhouse, the plant is trying to adjust to its "new" location in too much sun. If you want the plants to survive, our suggestion is to move them completely out of the sunshine or erect some kind of shade cover for them. You will also have to figure out some way to protect them in the winter, as they are not hardy to our low winter temperatures. We are also concerned about what appear to be the small size of the pots given all the foliage each is expected to support. You certainly do not want to repot them before going on your vacation; but in fall, we suggest you use a minimum of a 12 to 15 gallon pot and carefully repot each plant in good quality potting soil. When you lift out each plant, note if there are any roots circling the root ball and carefully unwind them. Try to spread them out when repotting.If they are very long (i.e.the plant appears root-bound) you may need to carefully trim back some of the circling roots after you have unwound them. Star Jasmine needs perfect drainage and should be watered regularly.. Fertilize the plant after flowering and again in early spring before new growth starts. Be careful when fertilizing plants in pots. Sometimes a slow-release product does the best job of slowly feeding the plant. Pruning back will keep the plant in shape (a mature plant can reach 20 to 30 feet and 10 feet wide). Since cut stems exude a milky juice, best to wear plastic gloves when pruning. Hopefully this information will help you manage these vines. .