Question
i have a primrose butterwort i have it in 1 part sphagnum moss 1 part peat moss and 1 part perlite and have rocks under pot with water in tray.one plant looks good but flower is dying .had to cover the other plant with dome. it looks better now they are side by side what am i doing wrong.pot are 5 in zone 6

Answer
Hi Toni,

It's not clear if you're growing your plants indoors or outdoors.  If you're growing them outdoors, then they are likely dormant in your area, as they are dormant at our nursery in zone 8.  Because you've mentioned flowers, I will assume that you are currently growing them indoors.  

Pinguicula primuliflora, also known as the primrose butterwort, is native to the northern parts of Florida.  It grows best outdoors where it could experience the changes in season.  From our years of experimentations, we've found that this plant grows poorly indoors.  When grown indoors, it's prone to rotting and fungal infections.  On the other hand, when grown outdoors in partial sunlight, they are very resilient and come back year after year.  No terrarium is required for this species or any Pinguicula species commonly found in cultivation.

If you've recently acquired these plants, it could be that what you're experiencing is shock to a rapid drop in humidity.  This will occur when you suddenly remove a plant that was growing in unnaturally high humidity, such as in a terrarium.

To acclimate your plant to lower humidity, cut a hole in the plastic dome, about 1/4 inch in diameter.  After 3-5 days, enlarge the hole slightly.  Wait another 3-5 days and enlarge the hole again.  After that, you could safely remove the dome altogether.  Also be aware that flowers last for only a week or so on these plants.  The dying flower could simply be the end of its life cycle.

When the risk of frost passes in your area, acclimate your plant to outdoor growing.  Place it where it would get dappled sunlight throughout the day.  

Good growing!
Jacob Farin