RichardG
Western Thunderer
Unfortunately, the little paper iris plants need to be supported after 'planting' in scenic glue for at least 45mins, just two at a time.
There are high-tack versions of PVA which provide a good initial grab:
Adhesive: Hi-Tack Glue: Original Gold: 115ml (12)
I suspect, tiny spots of this would hold small plants upright, and you could then add a little regular pva around the bases to add strength.
Can be had from independent craft shops and through eBay.