Don't scarify them but a short period of cold stratification might help with P. incarnata though I've never had a problem with just planting them. The fresher the seed the better. You might want to try soaking the seeds in orange juice or some other acidic liquid for a day or two before planting. Plant them just below the soil surface. Germination might be erratic with some sprouting in a few weeks and others taking months. Here's a great site for passiflora info

Here is a link that might be useful: Passie info

Since they have a hard shell, it would be a good idea to rub the seed between sand paper to abrade the surface to allow moisture to get in. This will aid germination. Bottom warmth will help in germination also. I'm not sure that cold treatment will help since these plants grow in areas that don't experience significant cold, as well as areas that do.

Passifloras are a hard coated seed that you do not want to scarify and P.incarnata is a cold hardy variety that can sometimes respond well to a period of cold stratification.

Why wouldn't you want to scarify it? Hard shells keep water out.

I stand corrected. The coat is permeable. Soaking in a citrus juice might help.

I really wish GW would let you edit posts... I just realized that it was already mentioned to try soaking in citrus juice.

thank you all for your suggestions. i did find the suggestion at the pfaf.org site to soak the seeds for 24 hours before sowing in a high pulp fruit juice such as passion fruit juice or orange juice. they say that the acid in the juices will soften the shell and speed up germination. another site forum suggested soaking in a 5% alcohol/water solution (also 24 hours) which is supposed to remove the chemical from the seed coat that inhibits germination and will speed the process. so gardenweb people, i'd say you are a bunch of winners for sure. first i'll find an orange, juice it up, soak the seeds and plant them. shall i let you know how many days before i discover a seedling or 2?