Raspberries in pots
Hello, We are trying to grow raspberries in pots as we are not able to plant them directly in soil. We have struggled to find much information about how to do this effectively. We are especially interested in how to prevent root rot or blight. But we are also trying to learn exactly how large a pot must be for optimum cane health. In addition to answering those two questions, can you suggest a video online that we could watch to learn more about growing raspberries in pots. Youtube offers limited options. Many thanks in advance for answering my questions!
Clatsop County Oregon
Yes, you can grow raspberries in containers! Select a sunny spot with at least 6 hours of sun each day, use a large pot (at least 18×18 inches deep and wide) and be sure there are good drainage holes. Use a high quality fertile soil. Complete information in these references (sorry no video)
To prevent disease, select a resistant variety of raspberry, the following are a few berry varieties with resistance information.
Killarney: Moderate resistance to root rot, immune to RBDV, Moderate vigor, Medium size, soft, medium to dark red, sweet, excellent flavor. Upright, sturdy canes grow moderately fast, and produce medium yields. For added interest, this raspberry puts on a show of pink blooms.
Cascade Bounty (U.S. Plant Patent 18,246): Excellent resistance to root rot, Vigorous, Medium size, medium firmness, can be a bit lumpy, bright red, fair flavor.
Heritage: Immune to RBDV, Vigorous, Medium size, firm, attractive, bright red, bland flavor, ripens late so has short fruiting season in cold climates. Fruit ripens in July and September. Erect canes are vigorous, need little support
EVERBEARING (TWO CROP) VARIETIES
Amity: Dark-red, large and firm, with classic raspberry flavor and superior quality. Excellent for fresh eating, jams, jellies, and freezing. Amity is resistant to aphids and root rot, and can take somewhat heavy soils. Starts bearing a week earlier than Heritage but will not bear quite as heavily. Recommended for home gardens.
Caroline: Large medium red berry. Strong, rich, full flavor. Very productive—ripens until frost. Resistant to grey mold, very vigorous
Thinning plants improves air circulation and reduces the moist conditions that allow many diseases to flourish. Cut any floricanes have finished fruiting to the ground immediately after harvest, especially if they show any signs of disease. Water is one-way fungal spores travel, so use drip irrigation and avoid splashing water when possible. Also, water early in the day so leaves can dry out before night. Fungal diseases thrive in warm moist environment. Keeping the area free of plant debris is helpful. This includes leaves, pruned cuttings, and uprooted weeds.
Other Fungal Diseases due to wet conditions include:
Anthracnose (Spot Anthracnose)
Caused by Elsinoe venata – a fungus that is spread by splashing rain or irrigation. Thrives in warm, wet weather (typically late spring/early summer). Overwinters in lesions on old canes. Commonly found on black raspberry and susceptible red raspberry plants, especially where disease pressure is high. Can be spread to new/healthy raspberry plants from nearby infected plants.
Symptoms: Reddish-brown sunken spots with purple margins and light gray centers on young shoots. Lesions are distributed throughout canes on sections between where the leaves are located. Spots grow together into cankers. Leaves may drop early. Fruit may dry up. May cause winter dieback.
Botrytis Fruit Rot (Gray Mold)
Caused by Botrytis cinerea – a fungus that overwinters in mummified fruit and infected plant debris. Spreads easily in early spring and thrives in warm, wet weather and even periods of prolonged cool, wet weather.
Symptoms: Presents as a gray, hairy mold which decays blossoms, green and ripening fruits, and harvested fruits. Infection may occur early in the season while symptoms may not be obvious until harvest time.
Caused by Leptosphaeria coniothyrium – a fungus that is spread by splashing rain or irrigation. Thrives in warm, wet weather (typically late spring/early summer). Enters through wounds made by insects, pruning cuts, canes rubbing against other canes/trellises, etc.
Symptoms: Large brown dead areas (cankers). Often first noticed when leaves wilt and wither.
Trellises are needed on some varieties. The everbearing type, are short and sturdy don’t require much trellising. Others varieties, mostly summer bearers, have long, weak canes that require support. Trellises can take a number of forms, but the most common is wire. You’ll also want to know how tall the variety you’re growing will be at maturity. You can prune canes back if they’re too tall, but, trimming off more than a quarter of the growth can reduce your harvest.