Margaret Lauterbach: A couple of unusual fruit trees to consider

It will soon be time to think about planting fruit trees and vines, since bare root prices are best in early spring. There are some unusual fruits for you to consider.

Remember we’re in USDA zone 7 now in the Treasure Valley. I still think it’s safer to consider our winter low down to minus 10 degrees F., zone 6. One unusual fruit newcomers from the east, middle west or the south may be familiar with is the pawpaw, America’s largest native fruit.

The pawpaw (Asimina triloba) is hardy here, hardy down to at least 20 degrees below zero. Keep in mind, though, that it is a taprooted tree, so if you have caliche underlying your surface soil, you’ll have to break that up and remove it before planting a pawpaw tree. Most of the Treasure Valley south of the river and above river level does have caliche hardpan. The pawpaw also thrives as an understory tree, protected from high sun, but it does require some sunlight.

The tree is related to the custard apple family, all of its relatives such as papaya, grow in the tropics. Here it’s not greedy for water, and in my garden, at least, has not been attacked by insects or slugs, while on the tree. Once fruit falls, though, the first-responding horde of millipedes set to work to begin the decay process.

Pawpaws in this area are much smaller than they are in other parts of the country, fruits 4 inches long is about their maximum size on my tree. The late fruit tree breeder and owner of the Fruitland Nursery, Warren Carnefix, made a sour face at my mention of pawpaws. The fruit isn’t sour, but it has the texture of a super-soft pudding and very little flavor. Plus very large black seeds, the size of lima beans.

The flavor of pawpaw is said to be like a combination of mango and banana, but the flavor is slight. Some folks love this fruit. It’s not usually available commercially because it bruises easily and has a short shelf life. Once picked, it won’t ripen further, but most people just pick up fallen pawpaws for immediate consumption. One woman commented online that unless you wait for the fruit to turn black, you’ll find a shortcut to the bathroom.

Vendor catalogs say two trees are necessary for pollination success. No doubt I’d get a lot more if my other tree hadn’t died many years ago, but I do get a light crop of fruit from my lone pawpaw. Pendant blossoms are a rich dark brown in color and they’re large.

Another fruit that may interest homeowners in this area is kiwi fruit. There you do need a male vine and a female vine to obtain fruit. A male vine is necessary, but can pollinate up to eight female vines’ flowers. The “fuzzy” brown roadapple kiwis are said to be hardy to USDA zone 7, our new zone, but if you rely on that, be sure you plant in a sheltered location. Provide very sturdy support for this vine, for one vine can bear up to a hundred pounds of fruit.

The hardy kiwi fruit is smooth-skinned, and closer to grape-sized, and may ripen to red or remain green when ripe, depending on the variety. You can eat skin and all on this fruit. Plants usually bear three or four years after planting. Again, you will need a male vine with as many as eight female vines, and the vines alone will be strong and heavy, even without fruit.

They need at least a half day of sun, if not full sun. They’re not demanding of much water, but they’re free of insect problems. Are the vines hardy? Yes, they are, down to minus 25 degrees F. Will you get fruit? Perhaps not. The vines of the variety I grew bloomed very early in spring, almost guaranteeing frost would kill any chance of fruit. One Green World carries a variety bred at Michigan State University, that produces large smooth fruits. The MSU area is colder than we, so that may be a good variety for this area. As soon as I can reach Dr. Fallahi at the Parma experimental station, I’ll report what he’s found about these fruits.

So with any fruit, remember, hardiness of the tree, shrub or vine does not mean you will harvest fruit.

This story was originally published December 9, 2015 at 3:13 PM with the headline "Margaret Lauterbach: A couple of unusual fruit trees to consider."