How old does a passiflora have to be before it starts blooming?

Its really not a question of age but more about the growing conditions you are providing. Ive been growing them for 5 years now. I grow mine in pots and I bring them in in the fall, cut them way way back, put them in a sunny window over winter then bring them back out mid-May and watch them explode to life again.

I bought one plant that took a couple seasons before it would actually bloom so just be patient. The key is making sure they have enough sun and nutrients! They love banana peels..or at least the potassium thats contained within them. During the summer I eat a ton of bananas and throw the peels into the passiflora pot. You could do that or...

Find a good water soluble fertilizer that has high potasium (potash or denoted on the package by the letter 'K'). When you shop for fertilizer you will see three numbers on the box or bag. The first number is nitrogen, the second is phosphorous, and the third is potassium. The numbers tell you the percentage of that nutrient in the bag. Beware though, too much Nitrogen and they will grow vigorously but not flower.

Azalea, Camellia & Rhododendron Food, Rose Food and Tomato Food are all good choices but again take note of the Nitrogen content. I used banana peels and Rhododendron food last year. Good luck and be patient. The flowers will come!

one year. they'll bloom this year.

here is a site www.passionflow.co.uk/ - hope it helps