Q. I have a Mexican petunia (Ruellia) that is about 4
years old. In 2013 the freeze caused all
of the stems to die back. I cut all of them off at ground level and the plant
grew back nicely and flowered beautifully.
Apparently, this winter the plant has very little dieback. Should I cut
all of the stems off at ground level or just the ones that have frost
damage? Will it flower from the existing
stems or does it only flower from “new wood”?
years old. In 2013 the freeze caused all
of the stems to die back. I cut all of them off at ground level and the plant
grew back nicely and flowered beautifully.
Apparently, this winter the plant has very little dieback. Should I cut
all of the stems off at ground level or just the ones that have frost
damage? Will it flower from the existing
stems or does it only flower from “new wood”?
A. Mexican Petunia is considered an herbaceous perennial
which means it freezes to the ground if it gets too cold and grows back from
the base. It is summer flowering so the flowers develop on new growth. Flowers
will develop on new growth from older wood as well as from new growth at the
bottom.
which means it freezes to the ground if it gets too cold and grows back from
the base. It is summer flowering so the flowers develop on new growth. Flowers
will develop on new growth from older wood as well as from new growth at the
bottom.
You have two choices. You can
prune it to the ground again just as if it froze back. It will grow from the
base and flower just like it had in 2014. That’s the easy way.
prune it to the ground again just as if it froze back. It will grow from the
base and flower just like it had in 2014. That’s the easy way.
Your second option is to keep it
at this height and remove anything dead or weak to the ground. Next, you would
cut the remaining stems back to a height where you want it to branch. Cutting
it back or shearing it will cause it to grow more densely above where it is
sheared and flower.
at this height and remove anything dead or weak to the ground. Next, you would
cut the remaining stems back to a height where you want it to branch. Cutting
it back or shearing it will cause it to grow more densely above where it is
sheared and flower.
The second method will give you
a taller plant if you want one. If you need to keep it small, then use the
first method.
a taller plant if you want one. If you need to keep it small, then use the
first method.
Remember to fertilize it now
with an all-purpose fertilizer for promoting flowers such as a rose fertilizer,
fruit tree fertilizer, tomato fertilizer or something similar.
with an all-purpose fertilizer for promoting flowers such as a rose fertilizer,
fruit tree fertilizer, tomato fertilizer or something similar.