Eight years ago, I planted several ‘Mystery’ gardenias. Today they are flourishing and will be covered with flowers all summer long.
But I take no credit for their success. For most of their eight years, they did not flower much. Yet, as I have learned with the passage of time, plants are a lot like children. If you can manage to keep them alive for a sufficient number of years, they will eventually find their own way.
Part of my gardenias’ eventual success, I have come to understand, is linked to the growth of the plants around them.
Gardenias appreciate elevated humidity in the surrounding air and this is achieved, in my case, by the growth of volunteer crape myrtle (Lagerstoremia indica) and pride of Madeira (Echium candidum) seedlings close by. With the foliage of these and other bushy plants transpiring around the gardenia, there is more moisture in the air with each passing summer. Although my gardenias face west, the afternoon sun is blunted by the shading presence of my gardenias’ companion plants.
Gardenias are definitely not shade-loving plants and do best growing in either full morning sun or partial afternoon sun. The healthiest gardenias I ever saw were growing on the east side of a car wash in Van Nuys. A steady mist coming from the car wash provided the ideal atmospheric ambience for the gardenias luxuriating there.
Gardenias are among the most puzzling plants for Valleyites to grow. Of every 10 gardenias I see in local gardens, at least nine look sad. Leaves are yellow or burnt, growth is spindly, and the plant as a whole looks ready for the compost heap.
Whenever I have trouble growing a plant, I learn about its habitat. If I can get to know its natural environment, I can attempt to duplicate that environment in my own garden.
Gardenias, indigenous to southeastern China, Africa and Oceania, are used to soil that is acidic due to heavy rainfall that leaches alkaline compounds out of the soil.
Hmm … acidic soil is the exact opposite of the alkaline soil found throughout the Valley. What’s a gardener to do?
You can acidify Valley soil by adding peat moss or gypsum to it during planting, by using fertilizer that is formulated specifically for acid-loving plants and by continual applications of compost. The breakdown of compost, in releasing humic acid, has an acidifying effect on the soil. Gypsum can also be applied twice a year after planting.
Regardless of the pH, your soil must be very fast-draining if gardenias are to have a fair chance of feeling comfortable in it. If your soil is compacted, mix in topsoil – sold in nurseries by the bag – whose primary constituent is sand. Adding compost also will improve soil drainage.
Root protection is a key factor in gardenia health. Like many tropical plants, gardenias grow best with their heads in the sun and their feet in the shade.
If your gardenia is a ‘Veitchii’ (VETCH-ee-eye), its growth habit is bushy and it will shade its roots completely as it develops. If your gardenia is a ‘Mystery,’ its growth will be more vertical and you will want to surround it with mulch and/or other plants.
If your gardenia is growing in a container, place a variety of tougher potted plants, such as geraniums and succulents, around it for protection from hot sun which, striking the sides of your gardenia’s container, would stress its roots on hot days.
With a gardenia, the only pruning required is removal of dead stems and trimming back shoots that go outside the natural shape of the plant. Gardenias should be allowed to reach their mature dimensions, 5 feet tall and 6 feet wide for ‘Veitchii,’ 8 feet tall and 8 feet wide for ‘Mystery.’
Gardenias prefer soil that is consistently moist but never overly wet and never dry. In summer, gardenias growing in the ground should be soaked every three days. In containers, they may need more frequent watering, depending on the container’s size and location. From March to November, apply a fertilizer for acid-loving plants, together with iron chelate, once a month.
Having said all that, I have seen gardenias that appeared to thrive on neglect. Once, in Valley Glen, I was introduced to a ‘Mystery’ gardenia that was 20 years old, had never been fertilized and flowered nonstop for months. It faced east and received a significant dose of morning sun.
I also am familiar with a ‘Veitchii’ gardenia in Sherman Oaks that is wedged against a fence in a side yard next to a concrete walkway. It is watered once a week, is never fertilized and keeps close company with a billowy, vining star jasmine (Trachelospermum jasminoides). It gets a few hours of sun each morning and is covered with flowers throughout the summer. It would appear that just as in real estate, location – or microclimate, horticulturally speaking – means everything to gardenias.
The history of the gardenia is intertwined with the first years of the American republic.
Alexander Garden grew up in Aberdeen, Scotland, where he studied medicine and natural history before voyaging to Charleston, S.C., where he took up residence in 1752. In addition to his medical practice, Garden became an avid plantsman and sent local specimens he discovered back to Europe.
It was during this period that the Swedish botanist Carolus Linnaeus began to give genus-species names, in Latin, to plants and animals, a system that would become known as binomial nomenclature. When Linnaeus received a plant from China with flowers that smelled like jasmine, he was persuaded to name it after Alexander Garden (Gardenia jasminoides) for his work in bringing wider recognition to newly discovered American plants.
Linnaeus sent a sample of the sweet-smelling newly named Gardenia shrub to Garden, who promptly planted it in his garden where, serendipitously, the Carolinas’ semitropical climate and acidic soil provided the perfect conditions for the first gardenia ever grown on the American continent.
Incidentally, a single gardenia bloom floating in a shallow glass bowl makes a pleasingly aromatic, stand-alone subject for a modest tablescape.
Tip of the week
For the Fourth of July my wife baked an apple pie whose fruit came from a ‘Golden Dorsett’ tree. ‘Golden Dorsett’ is the sweetest, most “appley” tasting yellow apple you can find. The tree was planted five years ago and hardly fruited at all until now. As in the case of ‘Mystery’ gardenia, ‘Golden Dorsett’ apple teaches the virtue of patience in the garden.