Every Garden Needs a Gardenia (or Two)

By Ms Sherry

‘August Beauty’

‘Klein’s Hardy’

The gardenias are blooming! Their divine fragrance perfumes every trip outside.  For me a garden without a gardenia is just not complete. Admittedly, gardenias may not always be the easiest plants to grow successfully but the rewards for a little extra effort are well worth it. There are so many cultivars to choose from – with some less plagued by a variety of typical gardenia problems. Some gardenias don’t tolerate extreme cold whereas others are almost impervious to arctic blasts; gardenias are picky about their soil, fertilizer, and water requirements. Some gardenias are magnets for insects and disease. Almost makes you want to say no thank you before you get started. A few tips, however, will help navigate the land mines when you grow gardenias.

As we always do, we are going to plant the right plant in the right place–that golden rule is really important when you choose a gardenia.
• Gardenias need to be planted high, the same as azaleas (top of root ball a half to an inch over the soil line).
• Gardenias prefer acid, well-drained soil.
• Gardenias enjoy fertilizer during the growing season, especially acid fertilizer (such as Miracid), fish emulsion or blood meal.
• Gardenias may need pruning to remove the faded blooms and straggly branches (if they have lost their full shape, you can also do a rejuenvation pruning by pruning a third of the canes to the ground yearly); prune after the end of the bloom season, never before.
• Gardenias appreciate regular water and, to me, don’t appear especially drought tolerant.
• Varieties of gardenias such as the commonly found ‘Mystery’ can be plagued by whiteflies or aphids; a good spraying with light horticultural oil (especially in the winter) can help control the damage; for me, it has been impossible to get rid of the insects completely (control may be your only success). Blackened leaves on gardenias come from the sticky reside, honeydew, left by white flies; the sticky stuff then enhances the growth of sooty mold. (Insecticidal soaps are not appropriate for gardenias according to the label.)
• Gardenias can be grown in large pots depending on how cold tolerant your cultivar is.
• Gardenias make a great hedge, foundation planting (provided you choose one of the smaller growing varieties) or specimen plant.
• Gardenias prefer part to full sun and don’t seem to bloom as well in shadier areas.

Gardenias to check out:
• ‘Klein’s Hardy’ – cultivar with a single bloom, hardy to 0 degrees, grows to 2 to 3 tall and wide; does not seem as vulnerable to whiteflies.
• ‘August Beauty’ – heavy bloomer with large double flowers this gardenia, growing to 4 to 6 feet high and about half that around, is to me the perfect gardenia for every yard.
• ‘Radicans’ is the baby gardenia ( there is even a variegated one); growing only 6 to 12 inches tall, it makes a great ground cover: ‘Radicans’ may not be as cold hardy as others (although mine has survived for years, untouched by winter nights in the teens).
• ‘Mystery’ – the most commonly known gardenia can get very large at 6 to 8 feet and is more prone to whitefly than others I have planted; mine has gotten frozen a couple of years, causing it to die back to the ground and return the next spring.

In blogs months ago we discussed the addition of fragrance to the winter garden to add interest. Summer is a time when there are so many choices that add color, fragrance, and texture to the landscape that we can just about be overcome. Gardenias, are, at the top of the list for adding fragrance in the summer. Additionally, the blooms are beautiful adding still more charm to the summer garden; during the winter the leaves add shine and color to the landscape. Gardenias are a four season plant and should be thought of as just more than a pretty smell.