Patience Reaps Rewards
How to encourage gardenias to bloom
By Kimberly Toscano
There is nothing so fragrant as the perfume of a gardenia shrub in bloom, enticing those nearby to linger in the garden. But, these Southern charmers are a bit bashful, sometimes needing some coaxing to flower. With a little TLC, even a beginner gardener can fill the landscape with the sweet scent of success. Whether you have a well-established heirloom, or are growing one of the newer varieties like Jubilation™ Gardenia, the following tips will help you keep your gardenias blooming year after year, bringing lovely color, texture and fragrance to your garden.
Feed your plants
Gardenias use a lot of nutrients to produce so many glorious blossoms. Feed your shrubs by applying an acidic, slow-release fertilizer such as an azalea or camellia fertilizer. For the organic gardener, blood meal, fish emulsion or bone meal work well. Apply fertilizer once in the spring after the threat of frost has passed, and again six weeks later. Soil tests are the best way to determine the specific nutrient needs for your garden.
Provide plenty of moisture
Water is essential for flower development. There is a strong correlation between available soil moisture and the number of flower buds that remain on a plant to maturity. During periods of water stress, a plant will drop many flower buds before opening, diverting limited water to roots instead of blooms. To avoid this problem, maintain an evenly moist soil, but avoid overwatering, as gardenias do not like wet feet. A good watering regime includes irrigating when the top two inches of soil feel dry. Water plants deeply, and use an organic mulch to maintain even soil moisture. Mulch is also important for weed management around plants because shallow-rooted gardenias do not tolerate cultivation.
Prune at the right time
Gardenias produce flower buds in late summer and fall for the next year’s blooms. To avoid removing these flower buds, wait to prune plants until after it finishes blooming in early summer. Gardenias typically need little pruning. Reshape plants by cutting back uneven branches and older, less productive stems. Faded flowers may be removed at any time. Plants will begin setting flower buds for the following season by late summer, so avoid pruning beyond mid-summer.
At times an apparently healthy gardenia will drop all or most of the developing flower buds just before they open. Such "bud drop" can result from several environmental and cultural factors. Water is often to blame, whether in the form of low humidity, overwatering or underwatering. Regular irrigation to keep the soil moist and use of mulches to conserve soil moisture may combat bud drop due to low moisture. Care should be taken to prevent overwatering.
Other causes of bud drop include insufficient light and high night temperatures during flower development. Gardenias require relatively cool night temperatures, between 50-55 degrees F for the formation of flower buds. Unfortunately, this source of flower failure is beyond the control of gardeners. Light intensity, on the other hand, is typically a factor of location. In some cases, selective pruning of nearby trees may adequately restore light conditions to support flowering.
A garden filled with heavenly-scented blossoms awaits the patient gardener who puts forth a little extra time to care for these finicky bloomers. For unrivaled aroma, try Southern Living® Plant Collection’s ScentAmazing™ Gardenia.