The Bloomerang Purple lilac, bred for repeat flowering and heat tolerance. It grows to five feet high. (Proven Winners)

Some flowering plants have an irresistible nostalgia quotient, something as emotionally potent as it is indefinable. It’s sort of like walking through the fog, your whole being wrapped in a mist you cannot grasp.

Nostalgia plants are entwined with memories, usually formative childhood memories, and they tend to have two elements — fragrance and grandmothers. I am short on grandmother memories, and the ones that persist have to do with floury potatoes boiled into submission. But other folks think of grandma in her garden amid such floral icons as hydrangeas, roses, lavender and, most of all, the lilacs. Nothing captures the essence of childhood moments with grandma like the lilac blossom. No doubt, this all has to do with the way scent triggers especially vivid memories.

In Washington, we love lilacs, but lilacs don’t love us. Or rather, they don’t like our climate. Lilacs hail from colder regions, so while they may have a moment here in April, they are fleeting and spend the rest of the year as hulking, sulking shrubs that, to my eyes, are coarse and lack grace. By August, they are dusted in powdery mildew. A viburnum or camellia out of bloom can still look good and contribute to the garden, but a lilac just sits there like a sourpuss. I’m thinking of the large, 12-to-15-foot common lilac, the sort your grandmother used to grow.

But in flower, lilacs have an appeal. Because they bloom so early in Washington — maybe six or eight weeks before they do in, say, upstate New York or Ontario — they capture the frisson of early spring, adding perfume to the thrill of young growth and bright blooms. I saw one coming into flower in Georgetown on April 4, which is early even for Washington lilacs.

The secret is to select varieties that have been bred to adapt to warm climates and to choose ones that are small so that, when out of bloom, they don’t draw attention to themselves.

A number of good, dwarf varieties have been around for years and are still commendable. One is Miss Kim, another is Palibin, a variety of the Meyer lilac that grows to just five feet high and seven feet across, and in spring is smothered in purple buds that open a lavender pink.

Over the past 16 years, plant breeders at the U.S. National Arboretum have introduced three varieties bred to be adapted to areas with hot, humid summers, as part of a breeding program that goes back decades. These varieties have a Chinese species named Syringa oblata in their parentage. The scent is not as sweet as the common lilac, but sufficiently “lilac-y.”

The first introduction is named Betsy Ross, and it is neither small nor purple — the flowers are white on a shrub that matures to 10 feet after 16 years. In 2006, the arboretum introduced to the nursery trade varieties named Old Glory and Declaration. Lilacs may originate in parts of Europe and East Asia, but they have been as American as apple pie for centuries.

Old Glory has bluish-purple blooms and a rounded growth habit, growing to a large shrub (if smaller than the common lilac) after many years. Declaration would be the one I’d plant; it stays small and has eye-catching, reddish-purple panicles.

Flowers of the National Arboretum’s Old Glory, a lilac variety with good tolerance of heat and mildew. (U.S. National Arboretum)

Declaration, another National Arboretum introduction, has red-purple blooms and a compact habit. (U.S. National Arboretum)

Other introductions are in the pipeline, but the work on lilacs is not as important to the arboretum as other woody plants. “We aren’t a big player in lilacs like we are with crape myrtles or flowering cherries,” said hybridizer Margaret Pooler. “But we have got a lot of good material,” she said, referring to the extensive collection of lilacs at the arboretum. The collection has 650 plants, including 440 unique hybrids.

In Grand Haven, Mich., a breeder named Tim Wood has produced a number of reblooming and smaller lilacs now entering the market through the Proven Winners brand. Rather ingeniously, they are called Bloomerang lilacs, and the third introduction became available this spring. They too are smaller and more tolerant of hot, humid summers, and have Meyer lilac blood in them.

They are named after their flower colors, and sold as Bloomerang Purple, Bloomerang Deep Purple and Bloomerang Pink. “The fragrance is a little bit different, still nice” said Stacey Hirvela, a spokeswoman for Proven Winners. She also commends a dwarf three-footer named Scent and Sensibility, which is pink in flower.

The low-growing lilac Scent and Sensibility. (Proven Winners)

The cutleaf lilac, Syringa x laciniata, is another lilac for hotter climes, and should be used more in gardens in these parts. It is compact and rounded with scented pink flowers, growing to six-to-eight feet. It has both regular and cutleaf leaves on the same plant, making it a conversation piece out of flower.

And speaking of out of flower, the collection of lilacs at the arboretum is not blooming much if at all this year because the shrubs were cut back hard in the winter as part of a rejuvenation measure. They will be blooming fully next year.

If you need a lilac fix, get thee to a garden center. But if you want to savor a common lilac (Syringa vulgaris) my advice is, give grandma a call.

More from Home and Garden:

Wholesale nurseries have their own Black Friday: It’s called April.

5 secrets of successful gardeners

Heuchera is a popular perennial for shade, but which variety is best?