I posted this in "Vines & Climbers" but thought it would be helpful to post here also. I planted several star jasmine (Trachelospermum asiaticum) plants in a planter next to my house (north side) which are doing very well. The vines have grown in to cover the area in two years, but alas, no flowers yet. They do get direct late afternoon sun and bright indirect light. We get temperatures into the twenties to upper teens so I think the plants get an adequate chilling for flowering. Although the plants are very green and healthy looking, I haven't been over fertilizing. Is there something else I should be doing to induce flowering. I see from general information on this plant that it flowers from mid-summer to fall. Maybe I just need to be patient, but I would appreciate any info regarding encouraging flowering.
Star jasmine not flowering
What type of fertilizer have you used on them?
I've used a Peters 20-20-20 soluble with trace nutrients only about 2 or 3 times since early spring so I don't feel I've over fertilized. The soil had plenty of compost dug into it a couple of years prior to planting. The foliage has a good dark green color typical for the plant. The plants have sent out several shoots and the 5 plants have completely covered a 2 x 15 foot bed. They have even started to climb up the stone wall and I thought about pruning them so they just frame the two front windows and not cover the whole wall. Per the suggestions of others, I think just waiting another year or two will be all that is needed.
I definitely agree on giving it some more time, but you might also consider fertilizing with something that's got a bit less nitrogen. Too much nitrogen can cause lots of green growth at the expense of blooms, and since it sounds like it's growing very well it's possible that it's getting more nitrogen than it really needs. They're pretty fast growing vines naturally though so it may still be that it just needs time.
Thanks for your suggestions. I haven't fertilized in a couple of months. One other thought was that maybe the plants weren't getting enough phosphorus. I suppose I should take a soil sample and send it in for nutrient analysis, but I didn't want to get that technical and don't think that's necessary since the plants are growing well and look great. I'll just wait and watch.
If you're giving it 20-20-20 that frequently I'm sure it's got plenty of phosphorus. Stopping fertilizing a couple months ago wouldn't have solved the problem if the issue is too much nitrogen--if it was going to bloom, it would have started blooming a couple months ago which means the buds would have had to form during the time that you were fertilizing it. I'd wait and see how things go next year, although regardless of whether the fertilizer was contributing to lack of blooms or not I really don't think it needs that much. I inherited one of the closely related T. jasminoides at my old house and don't think I ever fertilized it in the 3 yrs I lived there and it bloomed like a champ every year. Giving it some fertilizer every year is certainly fine, but I don't think that you need to do it as often as you did this year. If you do want to fertilize it at the same frequency, I would look for something that's a bit lower in nitrogen.