help germinating these vines seeds
hello, i have hard time germinating these vines from seed all from bignonia family. I am in zone 10 so we sow most of our seeds in fall as our winters are mild not below 5C while summers are extremely hot around 110F. Now spring is almost here. Right now temperatures are around 18-20C with rains these days. I surface sowed all these seeds and these seeds are surely 2010 seeds not before that. I got most of these in trade. I successfully germinated many seeds in fall including mandevilla laxa, evening primrose, venidium, akebia quinata etc but not these bignonia seeds.
1- Podranea ricasoliana pink trumpet vine
2 -Clytostoma callistegioides - lavender trumpet vine
3- Cydista aequinoctialis - garlic vine
4- pandorea jasminoides
I also tried enclosing the seedling pot in a polythene bag to speed up germination but no avail. Sprinkle very little coco peat on top. After sowing i keep my containers in partial sun, only first few hours sun then shade.
Any tips will be highly welcomed.