Question
My aunt lives in the Middle Island area of Long Island.  She has a gardenia that grows leaves but no blooms.  She pruned it to the point that it has only stalks.  During the winter months she keeps it indoors under a lamp in the hopes that it will bloom this spring.

Can this plant be saved?   If so, what should she do?

Answer
You are right to be concerned, Kate. Willynilly pruning can kill a perfectly healthy plant. Gardenias do not go dormant like deciduous shrubs in the North. If the stalks she kept have nodes and buds, it may well survive. If not, well, time will tell. Chalk it up to experience.

It sounds like auntie was desperate to get this plant going. Consider that most people are not THAT good at Gardenias to begin with, and keeping one alive on Long Island, indoors, is no small feat. Getting it to bloom just takes a few tricks of the trade.

Professional growers MUST know what makes Gardenias bloom and fluorish, because those are the Gardenias that will fly off the shelves.  You can use what they know to help your aunt become a better Gardenia Gardener.

Let's review the report, 'FLOWER INITIATION AND DEVELOPMENT IN GARDENIA PLANTS AS AFFECTED BY PHOTOPERIOD AND NIGHT TEMPERATURE.'

www.actahort.org/books/515/515_11.htm

Scientists E. P. Makridou and A. S. Economou exposed their Gardenias to different day lengths: 8, 12 and 16 hour days of light.  They did this experiment for 4 weeks.  Then they took ALL the Gardenias and gave them 16 hours of daylight for 4 more weeks.  Can you guess which Gardenias do had the most flowers?

Would you guess the ones that began with 8 hours of light?  12 hours of light?  Or the ones with 16 hours of light?

As it turned out, the Gardenias that had the shorter days and switched to longer days had the most flowers.  The researchers concluded that 'short photoperiods promote flower bud initiation in Gardenia plants.'

But that's not all!

They did another experiment.  This time, they exposed ALL their Gardenias to 8-hour days for 4 weeks, then split them up.  There were three groups.  Each got different day lengths -- 8, 12 and 16 hours long.

Do you think that changes in day length affected flowering?

Actually, the ones that had long days for a full 8 weeks -- days that were 16 hours long -- flowered soonest.

Then they did ANOTHER test.  They wanted to know if night temperatures would have any effect on Gardenias.  So they grew them ALL with 8 hours of daylight and set the thermostat at 75 degrees F; when the lights went out, they lowered the temperature to while the night temperatures were kept at 55, 65 and 75 degrees F.  And they did this for 4 weeks.  Then they CHANGED the night temperature.  ALL Gardenias were now spending their nights in a 65-degree F room.  They did this for 4 weeks.  And they tried several other combinations of temperatures as well, all with the same 8-hour day length.

Results:  Gardenias flowered earliest when exposed to days AND nights of 75 degrees F.  ALL the Gardenias flowered.

So if you want to use this research, Kate, you would want to tell your aunt to give your Gardenia only 8 hours of daylight for 4 weeks.

Then she would make the day longer.  She would give it 16 hours of daylight.  This Gardenia would have constant temperatures of 75 degrees F the whole time.

And she would have Gardenias coming out of your ears.  Without pruning!

People who grow their Gardenias in pots, as your aunt does, usually find that they dry out very quickly.  Growing one of these is not like growing them indoors, Kate.  The great outdoors is full of surprises, and these Gardenias do not take dry soil kindly.  Make sure, if you are part of this solution, that you watch it VERY carefully.

You can download the full text of these studies and read them for yourself with the links I gave you.  Remember that humidity is always important for these plants, that a low pH is their comfort zone.  All of this depends, however, on how she pruned.  Unfortunately, only time is going to tell whether she practiced Gardeniacide on her Gardenia.  Keep me posted.

THE LONG ISLAND GARDENER