will a Mystic River Butterfly and a Sunlight Sparklewing Butterfly both show up in the garden since there is a yellow and blue plant? or just the mystic?
If they were sparkling (ie attracting a butterfly) then both could come.
Yours aren't, though, so you aren't attracting butterflies to either right now.
do I need to replant to get them to come again?
You'd need to plant new butterpillaflora plants and then attach a chrysalis by spotting the relevant colour of caterpillar while the plant is between 3 minutes old and fully grown. Remember you can only hve one chrysalis at a time in your garden, so wait for one plant to reach FG before planting another.
how long will a plant attract a butterfly before its too late? if I have cake out and not tropical fruits?
They are fully grown for 5 days, and will attract the butterfly until they are RTH.