Heirloom veggies bring endless variety to garden plots

If I had a virgin plot of soil and could plant anything I wanted, I'd plant Brandywine and Pineapple tomatoes and Touchon carrots.

All three are heirloom vegetables. Heirlooms are old plant varieties that generally date from before World War II. They're usually open-pollinated, meaning they're pollinated by wind or insects, and come mostly true from seed. Gardeners could save Brandywine seeds knowing that next season, they'd be able to grow a tomato that was pretty much like the one they grew this year.

Old varieties like Brandywine began fading in popularity when plant breeders began hybridizing vegetables for better disease resistance, higher yields and fruit that didn't rot, bruise or tear during shipping. Hybrid does not mean genetically modified; it means people purposefully chose the parent plants to create a new plant with the characteristics they wanted.

But sometimes flavor fades when a tomato is bred for tougher skin or disease resistance. And a plant developed at a university, great though it may be, can't compete with the story of tomato seeds that came from Russia stuffed in the pocket of an immigrant.

In the 1970s, people began worrying about ebbing biodiversity and the disappearance of old plant varieties. A couple from Missouri founded Seed Savers Exchange (seedsavers.org). Now located in Decorah, Iowa, Seed Savers keeps a seed bank of more than 20,000 varieties of open-pollinated and heirloom plants.

Among their seed offerings is Minnesota Midget, a superb little melon that was developed at the University of Minnesota in 1948. Years ago, I grew this softball-sized melon in North Dakota, and was thrilled to get a bumper crop of fast-maturing sweet fruit.

Other seeds with Minnesota connections include the Swenson Swedish Pea, brought by an immigrant to Clinton, Minn., in the 1870s, and the Kanner Hoell tomato, originally from Germany.

So what's the downside to growing heirlooms? For home gardeners, especially those who want to grow tomatoes, disease is the main issue.

Tomato diseases linger in soil, which is why experts advise planting tomatoes in different spots each year. In a humid, rainy summer, a variety like Brandywine is much more likely to get leaf diseases than a disease-resistant hybrid like Celebrity. There are other issues. Brandywine tomatoes often split at the top and look warty and puckered at the bottom — it's just the way they are — while Celebrity usually looks pretty much perfect.

In a backyard that was mostly shaded, I built raised beds in a sunny spot and had success growing Brandywines and other heirlooms in soil that I partially replaced each year. But after a few years, I ran out of luck even though I rotated the heirlooms between my two raised beds. Though I supposedly did everything right — watering at the base of the plants with a hose, keeping the leaves dry, mulching beneath the plants and giving them plenty of room to increase air circulation — my Brandywines and Mortgage Lifters looked bad midway through the summer, and fruiting slowed. In a small veggie garden, I decided to stop wasting space on heirlooms and stuck with Celebrity, a fine, tasty tomato that I'm able to grow without any trouble.

So gardeners who want to grow heirloom plants should know that depending on what the growing season is like, they may face challenges. But that doesn't mean they shouldn't try. Last year I grew Touchon carrots, a French heirloom, and the results were spectacular! The carrots had almost no core and were tender and sweet.

In annual Master Gardener seed trials around Minnesota, where varieties are compared on measures like fruiting, performance in bad weather and seed germination, heirloom varieties like Golden Ball turnips and Bloomsdale spinach have done well. Touchon was a top-performing carrot, along with the hybrid SugarSnax. And Pineapple tomato was up there with hybrids Lemon Boy, Park's Whopper and Celebrity.

So add some variety to your garden, and try an heirloom or two. Many garden centers have old varieties for sale. After removing most of the soil from one of my raised beds, I hope to jazz things up this year by trying a Pineapple tomato plant to grow with my reliable Celebrities. Wouldn't it be something to have a yellow 2-pound tomato in the garden?