Dahlia grower Nick Weber examines young plants in his greenhouse in Brookeville, Md. (Adrian Higgins/Adrian Higgins)

One imagines organized and diligent gardeners to have put their muddy boots up over the holiday weekend and congratulated themselves on another May spent filling the pots with annuals and herbs, getting the tomatoes and peppers in and staked and generally priming the garden for the season ahead.

Much of my garden is ready, but a great deal more of it is not. I have a bushel basket of excuses, some of them valid. I spent a long day draining, cleaning and refilling my fish pond. This was a backbreaking chore that left me a wreck the next day. Thus, I lost two days that could have been spent preparing garden beds, transplanting the cucumber seedlings and grooming a rampant gooseberry bush while being careful to keep the ripening fruit.

The fish hate the pond cleaning as much as I do (I net them and keep them in a barrel), but now they are back frolicking in a pool that is as clean and fresh as an alpine stream, blithe to the fact there are tomato transplants in the basement craving a garden bed.

The problem with growing tomatoes (apart from the blight and the chipmunks) is that I start far more seeds, and varieties, than I have room for. The impulse is to stuff them into the ground, but such crowding is counterproductive. They need at least two feet of elbow room — three or four is better — so that they may luxuriate in leaf and become fruitful.

Finding the space has been complicated by a spring season that has been cool and damp, even if the tropical shift is upon us. The coolness was lovely for the gardener but caused the early-spring veggies to tarry in beds where the warm-season vegetables needed to go. As a result, the lettuce bed that was to have been succeeded with parsnips will now house tomatoes. The parsnip seed will be started indoors, ready to be planted out once the fava beans have finished in about a month. (That’s the plan.)

One edge of the vegetable garden is given over to flowers on the theory that one does not live on zucchini alone. The lily-flowered tulips — late, lingering and lovely — are now gone, replaced with one of the most valuable classes of plant for the hot months ahead, the dahlia.

The dahlia is diverse in form and spectacularly chromatic, and I have come to view it as both a staple and a luxury of the Washington garden from July to October.

Lulled into a pattern of mild winters, many of us got used to leaving the dahlia tubers in the soil, allowing them to resprout in April, when they could be dug carefully and divided. Gardeners who did that this winter lost their dahlia stock. I lifted mine in November but stored them poorly, so they desiccated and died. The upshot is that everyone is scrambling to find dahlia tubers this year. Most mail-order nurseries are either finished for the season or sold out. You will find started tubers at garden centers. A great source is the National Capital Dahlia Society, which holds its last tuber sale of the year June 11, 7:30 p.m. at the Bethesda Library, 7400 Arlington Rd., Bethesda.

I traveled to Brookeville to see Nick Weber, known to readers as an abiding expert on antique roses but also a dahlia man, and acquired a few from him.

My dahlia tastes have been rather timid in the past: I have limited myself to low-growing and generally restrained bloomers such as Bishop of Llandaff, Party and Flame from the Happy Single series, and Mystic Desire. (There are at least half a dozen in the Mystic series.)

With cap in hand, I had to take what my friend was willing to part with, and so my dahlia ad­ven­ture this year is going to be novel and daring (for me).

I like the sound of Lulu Island Mom, pure white with a dazzling orange center. “It looks like a big bunch of daisies,” he said with gusto. (The dahlia is in the daisy family.)

I wanted an orange variety, and he gave me Hotshot, which has four-inch blooms in a form known as semi-cactus: It’s fully double and no shrinking violet.

Weber raves over Taratahi Lilac, a cactus form with delicate violet-pink upturned petals. The swag also included Hart’s Lora Ann, a rich, crimson-red formal decorative type, and Snoho Doris, an exquisite ball type of rose-orange hue.

He then gave me a potted tuber that I knew would take me to the edge of my comfort zone: It was a dahlia named AC Abby, which is tall (above six feet) and with large blooms that are yellow in their centers with a magenta-pink exterior. I anticipate living with an effete punk rocker with spiky hair.

“I use six-foot stakes, and when it gets three or four pairs of leaves, I top it so you get more laterals,” he said. In other words, you’ll get a bushier habit and more flowers. This practice holds true for the others, too.

I also picked up a variety named Verrone’s Obsidian, but it wasn’t until I got to a computer that I realized what it was: the most bizarre dahlia I’ve seen, like a black purple pinwheel with an overdeveloped central disk.

Whether I find this too weird come August is beside the point. Dahlias have made a spectacular comeback, perhaps because they make magnificent cut flowers whose forms, sizes and colors are so varied that they fit almost any design style.

Don Dramstad, who raises dahlias for the cut flower trade near Waterford, Va., said that “12, 14 years ago you couldn’t give them away, and now they’re a prized commodity.”

He credits Martha Stewart and social media as catalysts in the dahlia renaissance. “I sell to designers from New York to North Carolina,” said Dramstad, whose enterprise is called Don’s Dahlias. Early in the dahlia season, designers crave the lighter blooms. In the fall, “they’ll want all-out color — oranges, purples and reds.”

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Also at washingtonpost.comRead past columns by Higgins at washingtonpost.com/home.