Hi; sorry to hear about your problems; I have a few questions; Are they getting direct Sunlight all Day? What Species is your Passionflower? Have you Been Fertilizing?

I Fertilize my Passi's once a week; depending on at what stage of growth I use different fertilizing methods. But when my Plants are just starting to produce Buds I use a fertilizer to help Blooming. That just may be all you need. I fertilize Weekly with this and I have great Flowers.

Hope this helps.
Chris

It has been getting direct sun all day long just recently. AS far as kind, I'm not quite sure, but I haven't been fertilizing at all. Is there anything in particular that you might recommend?

I use Miracle-Gro bloom booster during the growing season. I've also read that burying a banana or a banana peel in the soil is good for passion vines. It provides extra potassium but I've not yet tried it.
Karyn

I was having some of those same problems earlier this season with bud drop. It turned out to be stinkbugs who inject thier saliva into the vines and flower stems while sucking the juices out of the plant.

Here are a few common causes of bud drop:

Both stink bugs and thrips (very tiny whitish bugs that get into the flower buds) can cause bud drop. (open up one of the buds that fall and look for tiny little bugs=thrips. Stink bugs will be hiding in the vines and can be green or brownish in color and are shaped like shields).

-Too much water ~(have this problem sometimes here when it rains alot)- the roots stay wet and the soil therefore compacts and when the roots can't get enough oxygen, the plant will drop its buds. Make sure you have lots of drain holes in your pots and check with your fingers or a water meter several inches down before adding more water. Also a well-draining soil mix is important, I use half cactus soil to 1/2 potting soil (MG) and several handfulls of perlite mixed in.

-Too little water (as you already know)

- Extreme heat: more than the plant is used to will sometimes cause bud drop especially if it is already stressed.

There are probably some more I cant think of right now, so I hope someone else will comment.

Good luck
~SJN

My passion flower has bloomed for 19 years and last year stopped blooming. It looks green and it is giant. It keeps growing just doesn't bloom.