Question: I have three mature gardenias in my yard, all of which have weathered a variety of conditions since planted several years ago. However, I was concerned that this past fall’s drought would be their undoing since they didn’t receive supplemental water. Other than adding mulch and reducing the amount of fertilizer put around them, they were on their own. They still looked good before our current drought conditions lessened with late 2016 rainfall, but is there going to be a reckoning as 2017 unfolds?
Should I prune them back, or leave them alone and see how they do this spring? What other actions should I take to ensure they’re part of our landscape for years to come?
Answer: Let those gorgeous Southern shrubs raise their leaves and flowers high, as many gardenia growers and admirers are reporting similar experiences. My personal experience has also been positive so far (“knock on wood”), as have those of gardening friends across the area.
Supplemental water, while extremely beneficial during a drought, is not the only factor in gardenia survival. Your judicious use of mulch and fertilizer supported their survival, and brought to mind the question asked of me a couple of years ago – how can I kill a gardenia?
Other than questioning that person’s sanity, there are a few criteria that, if met, work in favor of gardenia survival and that of other plants as well.
Gardenias need acid soils in order to thrive. Whether you took a soil test and discovered they would be “happy” in your yard based on results, or took a gamble without testing and planted regardless, soil pH is critical to their health. If soil is between 5.0 – 6.5 on the pH scale, that’s a good start.
Gardenias, like azaleas, prefer to be planted “proud”, or a little higher than ground level, especially if soil in your yard is composed of Alabama clay. Plant them only as deep as the root ball or as in the pot it’s in, and then avoid cultivating around them to keep from damaging their roots. Your earlier reference to mulching around the plants was a good move.
While gardenias do best with regular water, about an inch a week, yours had a well-established root system which had a definite impact on their survival. And, although gardenias like a lot of sun in order to produce those lovely, fragrant blooms, afternoon shade with our heat and prolonged summer gives them a fighting chance. While shade wasn’t mentioned in your description, it’s more often those gardenias that receive some late-day shade fare better than those in full all day sun, especially in the absence of supplemental watering.
As for pruning your gardenias, the general recommendation is right after blooms fade in the summer. Gardenia jasminoides sets next year’s buds in the fall, so summer pruning allows some older wood to be cut back (about a third is safe) without damaging next year’s blooms.
I hope our gardenias prove their strength this spring, as gardenia lovers anticipate a return of their fragrance and Southern charm this summer.
For more information about this topic of other horticulture related topics please contact Sallie Lee, Urban Regional Extension Agent, at the St. Clair County Extension office at (205) 338-9416 or email firstname.lastname@example.org. Learn more about what is going on at the St. Clair County Extension office by visiting our website, www.aces.edu/StClair or liking us on Facebook. You may also visit one of the Extension Kiosks located at both the Moody and Ragland Library and the one in the St. Clair County Courthouse in Pell City.