Why are our favorite plants often the most difficult to grow well? Do we just need the challenge? Or, do we gardeners have some psychological need to always struggle? For whatever reason, I really like gardenias as a houseplant, and of course gardenias are one of the more difficult houseplants to grow properly. Let’s see if we can understand what these attractive and fragrant plants need, and how we can try and provide it.
Sun, Sun, and More Sun
The first requirement in growing and flowering a potted gardenia is sun. These plants really want and need a very sunny, bright growing location. You can’t grow them well when they’re sitting 20 feet from the window. During the cold months of the year they need to sit “in” a sunny window or on a sun porch. During the warm months of the year they greatly benefit from a season outdoors, again in the sun.
Potting Soil, Second Key Ingredient
The potting soil for your gardenia needs to be well drained and acidic. Potting soils bought at the local garden center or plant store rarely meet these requirements. If you want the absolutely based potting soil mix for a gardenia here’s your recipe:
1 PART FINE PINE BARK
1 PART PERLITE
1 PART SPHAGNUM PEAT MOSS
You can buy fine pine bark bagged for use as mulch. Make sure the pieces of bark are small, dime size is best. Perlite and sphagnum peat moss are available from most garden stores. Blend these three ingredients together and you’ll have your well drained, acidic gardenia soil mix.
Water and Feed Often
Once potted in our special potting mix don’t allow your gardenia to dry out or starve. Check the soil weekly and when dry to the touch water thoroughly using a diluted, water-soluble fertilizer. Mix the fertilizer at one quarter the recommended strength and use at every watering. Any of the commercial water-soluble fertilizers are fine.
Keep Cool in Winter
This might be the hardest requirement to meet but gardenias respond best to cool, not freezing, temperatures in the winter. This is the reason plants on sun porches or in unheated rooms do so well. They like their winter night temperatures dropping into the fifties if at all possible. If you can’t provide this, don’t despair, do the best you can with the temperature and see what happens. Give me a call and let me know when the first flowers open.