I've always been a city boy - I can't even coax a weed to grow. But I discovered a national treasure, practically in my own backyard, which made me wish my thumbs were greener.

Donna Frantz's greatest skill is not really the organic farming that has dominated her life for the last 16 years. No, she is the poster child for living your dreams with energy and passion. At age 81, she is not about to stop learning and doing new things.

You read that right - age 81. Donna and her husband, Leon, started a seasonal farmers market that eventually grew into a year-round florist and gift shop that they operated for 21 years. She really wanted a farm, though, and looked for one for 19 years. A farmer finally asked her if she was still interested in buying, and told her he would sell the next year. "I've already waited 19 years," she told him. "I can wait for one more."

So at age 65, when most folks are seriously contemplating retirement, they moved to the farm - her "25 acres of gold." I recently spent four hours there as Donna proudly showed me her farm. I even had a chance to ride on her tractor, a first for me. As long as she can physically work the farm and her mind stays sharp, there is no desire to retire.

"The soil around Waconia, Minn., is rich and black and perfect for my lifelong dream to grow and share these fabulous vegetables with people," Donna says. She is an organic gardener, and has been all her life.

The produce is picked fresh daily, washed and brought into the lower level of their renovated and restored 1890s German bank barn, which houses her business, At the Farm. The stone walls keep the space cool, even on the hottest days of summer.

Besides produce, she also sells seeds, herbs, flowers and vegetable plants. Her five employees, whom she refers to as her "elves," taste everything before they sell the crop - just to be sure it meets her standards.

But the most important commodity Donna dispenses is wisdom: farming advice to be sure, but also motivation, dedication, common sense, and how to live with passion.

Her mom and dad were farmers. Her mother told her never to be a farmer. "Mother had an A-plus work ethic," Donna said. "Dad was outgoing with a terrific sense of humor. Dad said never, never, never worry. He just flew by the seat of his pants and had a let-it-flow attitude."

To live her dream, she ignored her mother's advice. She works every day -- seven days a week. She's never had a vacation. Her vacation is on the farm. She doesn't go anywhere else. She loves work and can't believe she created this.

Every morning, she gets on her tractor and travels around her farm and continually reminds herself that all this is beyond her wildest dreams. She reads self-help books, not for enjoyment, but to learn. She says you cannot learn enough in a lifetime.

I asked one of her employees to share Donna's secret: "She's always in the moment. She always wants to know what is going on in our lives and the lives of customers - success of kids, sickness, vacations, everything." We do something similar here at MackayMitchell Envelope with our Mackay 66 customer profile.

Then I asked Donna to prioritize what made her successful. Aside from her first answer, which is what every good farmer would tell you, the rest of her advice is universal, regardless of the business you're in.

1. Soil. The soil smells good after it rains.

2. Quality of products. It's important to not be too economical and don't let the cost of your seed get in the way of quality. You must have good seed to be successful.

3. Research, research, research. If it's a new seed, you test and test. You will never know how good it is until you grow it and try it.

4. Be good to your customers. Tell them when you don't know.

5. Above all, you must be honest.

6. Stand behind your product. If someone gets a bad melon, they can throw it away and get a new one.

Donna said, "I don't care how many zeros you have in sales - from $1 million to $100 million - business concepts won't change. It's better than money when people like what you do."

Mackay's Moral: It's never too late to plant the seeds of success.

Harvey Mackay is the author of the New York Times best-seller "Swim With the Sharks Without Being Eaten Alive." He can be reached through his website, www.harveymackay.com, by emailing harvey@mackay.com or by writing him at MackayMitchell Envelope Co., 2100 Elm St. SE, Minneapolis, MN 55414.