April 29, 2002 -- For urban dwellers who may as well think fruit grows in a supermarket, horticulturalists are developing trees that offer more fruit for your dollar — and space.
The so-called fruit salad tree sprouts as many as seven varieties of fruit in one tree. The combinations aren't quite as diverse as bountiful fruit bowls — apples and peaches, for example, can't mix. But the trees combine several members of fruit families into one.
A citrus version grows oranges, mandarins, lemons, limes, tangelos, lemonades (a rounded fruit that's sweet like lemonade) and grapefruit. A stone fruit tree yields peaches, apricots, plums, nectarines, peachcots (a cross between peaches and apricots) and peacherines. The trees can be planted outside in small back yards (depending on their climate requirements), or kept in a pot. Most are self-pollinating so no partner trees or pollinating bees are needed.
"Houses are getting bigger and lots are getting smaller," said Lisa Bradford, a sales associate with Tsugawa Nursery in Woodland, Wash. "We think that's what's making these multiple fruit trees more popular."
New Trees, Old Concept
Tsugawa Nursery offers stone fruit salad trees, which it buys from Dave Wilson Nurseries in Hickman, Calif. Durling Nursery of Fallbrook, Calif. offers multiple citrus fruit trees. And James and Kerry West of the Fruit Salad Tree Company offer an ambitious line of mixed fruit trees through their orchards, based in Emmaville in New South Wales, Australia. The Wests have just begun marketing their trees to the United States through online shipping.
Not only do the trees offer a variety of fruit in one batch, the fruits' different harvesting times prevent a glut in produce at one period. That may be impractical for large fruit producers who need to harvest rows of trees at once, but it's tailor-made for those who simply want to pluck the fruit for their own eating.
Fruit salad trees may be growing more popular now, but the technique used to craft them — grafting — is nearly as old as fruit tree growing itself.
Grafting can involve a number of different styles, but the basic idea is to cut a shallow layer of bark on a base tree, peel it back and insert a small twig or single bud from another tree. The grafted section is then sealed with tape.
"Grafting is not just a science, it's an art," said Ian Greig of Greig Associates, an agricultural consulting company in Tampa, Fla. "I've seen some graft and everything take. Then others try and everything dies. It's like being a surgeon."
The goal is to match the cambium layers of the rootstock and the scion, or inserted twig. The cambium layer is a narrow band of cells just inside the bark that carries water up and transports the sugars of photosynthesis down.
Today the majority of fruit trees are grafted at an early age to create trees with pest-resistant rootstocks and branches that produce bountiful, desirable fruit (resistant rootstocks often yield little or poor fruit on their own). It's also common to combine several varieties of one fruit — such as multiple pear or apple species — on a single tree.
The fruit salad tree takes that concept a step further.
"There's an ease in having multiple fruits in one," said Kerry Retzel, an urban horticulturalist in Chelan County, Wash. "Today, with people having little time and space, it's a good option."
There are some drawbacks. If spraying is needed to keep pests at bay, harvesting can become problematic. Robert Crassweller, a tree fruit professor at Penn State's College of Agricultural Sciences, explains there's a limit to how soon fruit can be harvested after applying a pesticide.
"An early maturing variety and a late maturing variety might not leave you much of a window to spray," he said.
Also, trees with different kinds of fruits can grow in a lopsided fashion since, for example, grapefruits grow much faster than limes.
"You'd have to keep a beady eye on the branches and keep them trimmed so one fruit doesn't out-crowd another," said Bob Knight of the Tropical Research and Education Center at the University of Florida in Homestead.
Then again, keeping a beady eye on the branches might not be such an overwhelming task since it is, after all, only one tree.