For optimum production, raspberry plants need light sandy loam. Many raspberry crops are planted on raised beds or hilled rows. Soil should be prepared prior to you receiving the plants. Thoroughly till the soil. Eliminate any perennial weed problems. Access to water is critical to successfully growing raspberries. Raspberry plants also perform best in full sun, with good air movements. Raspberry roots grow too large for containers so this method is not recommended. A few canes can turn into a thick patch in 2 to 3 years. Plan your site and space accordingly to allow for this expansion.
Adequate spacing is important for best yields. When planting in rows, space plants 2 to 2 1/2 feet apart. Space rows 8 feet apart, leaving enough room for your equipment to maneuver between rows. Plant roots into furrows 2 inches deep, with the top of the soil at the base of the cane. Spread the roots along the length of the furrow, do plants roots straight down. Do not plant deeper than 2-3 inches in loose dry soil, raspberries planted too deep will not survive. Push soil into place around the plant. Proper soil moisture is very important during the establishment year. Use caution when weeding and don’t hoe deeply, possibly causing damage to the roots. Mulching may also help reduce weed development.
Raspberry plants should be fertilized twice a year, once before new growth in early spring and once again in late May, when flowering. Contact your local Ag extension center or University for exact fertilizer usage in your area.
An adequate water supply is critical for high yielding raspberry plants. Drip irrigation is the recommended method of watering for most raspberry plants. When using a trellis system to support and train your raspberry plants, you can attach a drip-line to the second guide wire, or approximately 2 feet off of the ground. This reduces the chance of damage to the drip-line when pruning and maintaining your plants.
Water your plants periodically during the growing season if rain doesn’t occur. This is especially important during the period of fruit development.
Support / Trellis
Raspberry plants perform best when used with a support/trellis system. Trellises keep the canes upright which prevents the fruit from touching the ground. A trellis system also helps maintain good aeration which may reduce plant diseases and makes picking easier.
Trellises can be installed during the fall of the first year of growth. A trellis generally consists of 3 to 4 guide wires stretched along wooden posts spaced 30 feet apart. No. 10 or 12 galvanized wires are recommended. Space the guide wires at 1 ½ feet, 3 feet and 5 feet from the ground. The bottom guide wire height can be adjusted to best suite the raspberry plants.
Training and Pruning
Primocane raspberry plants bear fruit on the canes that come up that year. A trellis system may be used with primocane raspberry plants. They can also be left to grow free standing. Primocane raspberry plants will produce fruit until the first hard frost. When the crop is over and the canes have dropped their leaves, cut all canes to the ground. Canes can also be mowed. Cut as close to the soil surface as possible, leaving no stubs.
When training floricane raspberry plants, after the season’s growth, tie long enough canes to the first guide wire on your trellis. In the following seasons, canes that have produced fruit should be cut out any time from the end of the harvest through late winter. These cane should be cut as close to the soil as possible. The number of canes a hill can support is decided by moisture, soil fertility and planting distance. Keep all good strong canes each plant will produce. Generally this means 8-10 canes. Tie canes to the top trellis wire. Postpone cutting canes back or tipping them until late winter or early spring after the danger of hard freezes have passed. Canes are usually cut back 4 ½ to 5 ½ feet.
Do not plant raspberries where potatoes, tomatoes, peppers, or bulbs have grown unless the soil has been fumigated. These crops are hosts for the disease Verticillium Wilt, a fungus that can stay in the soil for many years and may infest the raspberry crop. Raspberry plants are also very susceptible to root rot.