What's a great way for lawn and landscape firms, garden centers, nurseries and other green industry companies to boost sales in these competitive times? Ask current clients about future needs.

Ask: "What about ...?" No question leads to more sales than one with those two words.

As in: "What about fertilizer application?" Or: "What about insect and weed control?" Or: "What about placing your poinsettia orders this summer for your Christmas party?"

Many clients have other needs. What they don't have is knowledge that you can handle them. They may be clueless that you also offer aerating and planting services, or that you consult with customers about xeriscaping, or that you also install pools, spas and putting greens.

Tell them when you pose those "what about" questions. And tell them as you ask about "Phase II" of the current project or discuss upgrades.

"What abouts" work wonders and help convert single sales into long-term relationships. That's because your current clients — even the newest ones — are your best ones.

Peter Drucker, the renown management consultant, estimated that the average company has a 1 in 14 chance of doing business with a prospect, a 1 in 4 chance with a former client, and a whopping 1 in 2 chance with a current client.

Upselling an existing customer both makes and saves you money. Estimates are that the long-term value of each client is more than 100 times the value of a single transaction. Then, too, it costs five times more to attract a new customer than to retain an existing one.

Boosting sales with your current clients may be much easier than you think, once they know all that you do, or can do.

Recent research by Lawn & Landscape Magazine revealed that 75 percent of consumers say they would buy more than just basic treatments from their contractor if the contractor said it would make their lawns and plants healthier and more attractive. And 67 percent of homeowners use the same contractor for such services as chemical treatment and mulching as they use for mowing, trimming and edging.

How lucrative can add-on sales be for a landscape company? Very, says Jason Fawcett, the president of Elizabeth River Lawn and Landscape in Suffolk, Virginia. He has estimated that upsells comprise up to 40 percent of his company's business.

The idea of working more with current clients brings to mind the book "Acres of Diamonds" by Russell Conwell. It recounts the ancient tale of a Persian farmer so desperate to find diamonds that he sells his property and goes off in futile search for them.

Ultimately he spends all his money, and becomes so despondent that he drowns himself in the ocean. Meanwhile, the man to whom he sold his home discovers a rich diamond mine — on the property.

Are there diamonds in your backyard?

Before seeking prospects for your lawn and landscape or other services, consider what else to offer your clients.

They're the ones who know you. They're the ones who trust you. They're the ones who value you.

And they're the ones who will respond favorably to your "what about" questions.