Ask a Specialist Answer
What apple varieties do you recommend for a new organic orchard?
Most people can name a few apple varieties: those available at grocery stores, those we remember from childhood, maybe a few more for people who regularly visit a local orchard in the fall. But there are tens of thousands of named varieties of apples, with dozens of different characteristics—colors and flavors, sweetness, texture, winter hardiness, time of ripening, horticultural needs. Deciding which ones to grow in a new orchard can be overwhelming. If you’ve decided that you will grow organically, whether you want to be certified or not, selecting varieties that have some disease-resistance will help you have high-quality fruit while limiting the inputs you’ll need.
Apple Scab Resistance
One of the most economically devastating diseases that affects apples in the Midwest is Apple Scab, a fungal disease that goes through two generations a year. The first cycle colonizes the leaves, and the second gets to the apples. Fallen leaves and fruit on the orchard floor carry spores over to the next year to start the cycle all over again. Once scab inoculum is established in your orchard, it can be very difficult and costly to fight.
In 1926, a collaborative breeding program of Purdue University, Rutgers University, and the University of Illinois (known as PRI) identified a gene for scab resistance and has since released a number of varieties that are highly resistant or immune to apple scab. Some of these varieties, which are commonly referred to as disease-resistant, are susceptible to other common diseases. Liberty, Priscilla, Pixie Crunch, Jonafree, William’s Pride, and Gold Rush are popular varieties that are bred for scab resistance or immunity but are also naturally resistant to other diseases.
Pristine, Crimson Crisp, Redfree, and Crimson Topaz are PRI apples that are scab resistant but tend to be susceptible to fire blight and/or cedar-apple rust. Fire blight can be devastating to an orchard but is less ubiquitous than apple scab. Depending on your orchard conditions, cultural controls can be effective at limiting the risk of fire blight, and you may have success with those varieties.
Natural Tolerance to Common Diseases
Unlike apple scab, there is no identified gene for resistance to most other diseases. However, there are identified varieties that show a natural resistance to fire blight, cedar apple rust, sooty blotch, and flyspeck (known as “summer diseases”), as well as apple scab. These varieties are sometimes referred to as “tolerant” of various diseases. The ever-popular Honeycrisp is one of them, though many growers eventually get frustrated by Honeycrisp’s more intensive horticultural needs. Akane, an older apple developed in Japan, is an early variety that’s often grown in organic orchards, as is Florina, a French apple that’s a favorite of this farmer. Other varieties in this category include some names that were common on older farmsteads—Wolf River, Enterprise, Spartan, and Jonagold, for example. More anecdotally, a lot of growers find some older varieties from the University of Minnesota to be fairly easy to manage—Haralson, Chestnut Crabapple, and Sweet 16, for example—even though they are not commonly categorized as resistant.
Heirloom apples are an interesting source of disease resistance. Since there are a lot of named cultivars that were developed long before modern inputs and farm technology were available, many are well suited to minimal management. Duchess of Oldenburg, St. Edmund’s Russet, Worcester Pearmain, Egremont Russet, Golden Russet, Tydeman’s Red, and Belle de Boskoop are a few good examples. It doesn’t hurt that they have some great names! But it’s important to be careful with heirlooms. Others, such as Ashmead’s Kernel, Northern Spy, and Roxbury Russet are quite susceptible to one or more of the common diseases.
After perusing the lists of apples in each category, it’s a good idea to talk to people in your region about their experiences with the varieties you’re considering. Certain characteristics of apples might not pop up in research literature or catalog descriptions that can nonetheless have an impact on your growing experience. Some apples may be listed as hardy, for example, but you’ll learn from your neighbors that they’ve lost them in cold winters. A variety might not consistently ripen in a normal fall, or might be especially sensitive to spring frosts. As with most things, the experience of other farmers is one of the most valuable resources.
Posted: May 2021
Answer By: Rachel Henderson