Fall Fruit Reminders

Late-season care is critical for fruit crops in Iowa. As temperatures cool and rainfall becomes scarce, raspberries, strawberries, and grapevines face unique challenges that can impact both current and future yields. Timely irrigation and disease management help ensure healthy plants and productive harvests.

Raspberries

Fall-bearing (primocane-bearing) raspberries, especially the cultivar 'Heritage', are commonly grown in Iowa. As late summer progresses, temperatures have dropped and precipitation has decreased. Because raspberries are shallow-rooted, they are particularly vulnerable to drought stress. Without adequate moisture, fall-fruiting raspberry plants often produce small, crumbly fruit (Figure 1) and suffer reduced yields. To maintain fruit size and productivity until frost, it's important to water these plants during dry periods. 

Strawberries

Most strawberries grown in Iowa are June-bearing cultivars (Figure 2). Although they are not fruiting currently, ongoing management throughout the season is important for successful production. Like raspberries, strawberries have shallow root systems and are susceptible to drought stress. Providing supplemental water during dry fall conditions improves plant health and vigor, resulting in a more productive crop the following season. 

Grapevines

Even after harvest, grapevine foliage should be monitored closely. Downy mildew is a common late-season foliar disease that affects many grape cultivars. Early symptoms include yellow and brown splotches on the top sides of leaves (Figure 3), which may develop into white, fuzzy masses of spores on the undersides (Figure 4). This disease often causes partial or complete defoliation (Figure 5), reducing cold hardiness and interfering with the fall hardening off process. These effects can lead to lower yields and increased disease pressure in the following year. To prevent such issues, it's important to maintain a healthy canopy until the leaves naturally senesce due to shorter days or fall frost.