Mary, Mary quite contrary, how does your garden smell?
Hmm, is that how the rhyme goes? No, but do you give thought to odors in your landscape?
I’m not talking about bad odors — I’m referring to the sweet smells of classic southern gardens. If you don’t suffer from allergies, now is the time to stop and smell the magnolias, gardenias, and star jasmine.
Magnolia grandiflora, the name says it all. No wonder Louisiana and Mississippi chose the southern magnolia as their state flower. Large white flowers set against glossy, dark green leaves appear in April and peak in May. With flowers averaging around 8”, the fragrance of these blooms fills an entire yard.
Southern magnolias are medium to large trees, averaging 40-50 feet tall with a spread of 20-30 feet. No room for a large tree? Two dwarf varieties are available. Little Gem, a 2018 Louisiana Super Plant, reaches a mature size of 20-25 feet tall by 8- 12 feet wide. Often, Little Gem will keep producing flowers up until fall. Teddy Bear is another dwarf cultivar, reaching a mature size of 15-20 feet by 10 feet.
While evergreen, trees do drop leaves in late spring. Seed cones will also form after flowers fall. Mature trees produce large surface roots that can crack concrete and patios. It’s best to locate them in areas where this won’t be a nuisance.
Likewise, large surface roots and a dense canopy make it difficult to grow grass under the trees, so mulch under them with a 4-6” layer of leaves, pine straw or bark. Magnolia roots are very sensitive and will grow poorly if planted too deep.
The smell of gardenias reminds me of the end of school. Every May, limbs of these shrubs look to be straining under the weight of numerous white flowers. A small arrangement of cut gardenias will feel your house with their intoxicating perfume.
While not difficult to grow, proper conditions are needed for healthy shrubs. Gardenias do best in acidic soil (pH 5.0-5.5) that is well drained. Be careful you don’t plant too deep and only lightly mulch around them (2–3-inch layer). Uniform soil moisture is important, but overwatering will lead to root rot.
A slow-release fertilizer after blooming will supply adequate amounts of nitrogen. Applications of iron are usually necessary if soil pH is too high; iron deficiency causes yellowing on newer leaves. Any pruning should be done immediately after flowering has stopped.
Common varieties include Daisy, August Beauty, Jubilation, Scentsation, and the popular Louisiana Super Plant – Frostproof. Jubilation and Frostproof are more compact, with mature sizes of 4 feet by 3-4 feet and 5 feet by 4-5 feet, respectively. Check the mature size of other varieties before purchasing. Large plants can reach heights of 10-12 feet!
Star or Confederate jasmine (Trachelospermum jasminoides) are in full bloom now. These woody climbing vines are popular across the lower and coastal south for the explosion of small white flowers that fill the air with their scent. The evergreen vines make an attractive covering over arbors and pergolas. Mature vines will be heavy, so give them adequate support and prune excessive growth after flowering. They can tolerate full sun to shade.
I guarantee if you have any of these plants in your garden, it smells wonderful right now. As temperatures warm and humidity creeps up, the air seems to hold onto the sweet fragrances. I guess that’s one plus for living in the south!
Look around for where you can add one of these to your landscape this fall. All will do best when planted between November and February.
Clark Robertson is the assistant county agent for horticulture for Livingston and Tangipahoa parishes. For more information on these or related topics, contact Clark at (225) 686-3020 or visit www.lsuagcenter.com/livingston.