ABOUT RASPBERRY
Rosaceae
Relatives: Thimbleberry, Wineberry, Dewberry, Blackberry
Raspberry plants form several erect or sprawling stems each year. At the same time the 2-year-old canes die back. They usually have some thorns, but not nearly as many as blackberries (unless you have RRN Blackberries, which are thornless!). The roots of Raspberries are perennial thought the canes usually only live about two years. The first year of a new Raspberry's life is mostly spent growing vegetatively, while the second year they flower and produce fruits before the canes die back that second year. Raspberry can easily live for over 15 years.
Growing Raspberries and Blackberries
Prepared by David T. Handley, vegetable and small fruit specialist, University of Maine Cooperative Extension
blackberriesRaspberries and blackberries can be a most enjoyable crop for the conscientious gardener. Red raspberries are readily adaptable throughout New England, but black and purple raspberries and blackberries lack the hardiness to be grown north of well-sheltered sites in southern Maine and New Hampshire.
Selecting a Planting Site
To get the most out of your raspberry planting, choose your site carefully. Raspberries prefer full sunlight and grow best in well-drained, sandy loam soils rich in organic matter. Avoid low areas that remain wet late into the spring, but select a site with access to a water supply. Irrigation is important for good plant growth during dry periods and can improve fruit size and yield. <b>Do not plant raspberries where tomatoes, potatoes, peppers, or eggplant have been grown within the past four years, because these crops carry a root rot called Verticillium that can also attack raspberries.</b> Destroy all wild raspberry and blackberry plants within a distance of 600 feet of your planting site if possible, to reduce the possibility that virus diseases might be spread to your planting.
Preparing the Soil
Getting the soil ready for raspberries may take up to two years, depending on its condition. Test the soil to determine its pH and fertility levels. Raspberries prefer a soil pH of 5.6 to 6.2; acid soils may require applications of ground limestone to increase the pH. Soil testing information is available from your county Cooperative Extension office. You can improve the level of organic matter in the soil and discourage perennial weeds by sowing a cover crop such as buckwheat, rye, millet, or oats, and plowing it into the soil before it goes to seed. There should be time enough for two sowings in a single season. Applications of barnyard manure or compost and repeated tilling for a full season can be substituted for cover cropping. Be aware that animal manures may contain weed seeds that can become a problem in your planting later. In the spring of the planting year, spread 25 pounds of 10-10-10 garden fertilizer per 1,000 square feet of planting site. Organic fertilizer sources such as compost, manures, sul-po-mag, and rock phosphate may be used in place of synthetic fertilizers. Apply enough of these materials to deliver two pounds each of nitrogen, phosphorus (P2O5) and potassium (K2O) per 1,000 square feet. Cultivate the soil several days before planting to incorporate the fertilizer and break up any clumps or clods.
The Raspberry Plant
The crowns and roots of raspberry plants are perennial, but individual canes live two years. Each spring, the plants produce canes (suckers) from buds on the crown and on underground lateral stems. These canes grow vegetatively during the first season, overwinter, and produce fruit during the summer of the second year, while new canes emerge to provide a crop for the following year. Second-year canes die shortly after fruiting. Everbearing raspberries bear a crop on the tips of first-year canes in the fall, followed by a typical summer crop on the lower portion of the canes the second year.
It’s easy to tell first-year canes from second-year canes. First-year canes have green stems, while second-year canes have a thin, brown bark covering them.
Although a wide selection of raspberry varieties is available, only a few will do well under the short growing seasons and severe winters of northern New England. Select only those that are rated very hardy with early or mid-season ripening.
In general, red raspberries are the hardiest type, followed by purple raspberries, black raspberries, and blackberries. Temperatures below 5°F will injure or kill blackberry and most purple and black raspberry canes, so these should only be planted in southern parts of Maine and New Hampshire, on protected sites.
Order your plants from a reputable nursery or garden dealer. Specify disease-free, virus-indexed stock. Most raspberries are sold as dormant, one-year-old canes, but some nurseries offer plants generated by tissue culture, or micropropagation. Tissue-cultured plants may be more expensive, but they are less likely to have disease problems.
Suggested Varieties
Red Raspberries
Boyne: Early ripening. Large crops of medium-sized, dark red berries with good flavor. Short, spiny canes. Very hardy.
Killarney: Ripens mid-season. Medium-sized, bright red fruit with good flavor. Short, spiny canes with many fine thorns. Very hardy.
Newburgh: Ripens mid-season. Large, round, bright red fruit with fair flavor. Good for freezing. Vigorous plants with very few thorns. Hardy.
Nova: Ripens mid-season. Medium-sized fruit, bright red, firm. Resistant to most cane diseases.
Latham: Mid-to-late ripening. Medium-large fruit, prone to crumbling, with fair flavor. Plants are vigorous with few thorns. Very hardy.
Prelude: Very early ripening, good quality fruit on vigorous canes. Hardy.
Encore: Late ripening. Large fruit of good quality, vigorous plants. Hardy.
Black Raspberries
Jewel: Mid-season ripening. Firm, glossy fruit with good flavor. Vigorous, erect plants.
Early Sweet: Early ripening, firm, glossy with good flavor. Vigorous plants.
Blackberries
Darrow: Large, glossy fruit with good flavor. Vigorous, erect plants with large thorns, but susceptible to virus.
Illini: Large fruit, vigorous plants with large thorns.
Everbearing Raspberries
August Red: Earliest ripening of everbearing types. Soft, medium-sized fruit with fair flavor. Short, spiny canes.
Autumn Bliss: Early ripening fall crop with large flavorful fruit. Canes are moderately vigorous with few thorns.
Fall Red: Early ripening fall crop, but may be too late for northern Maine and New Hampshire. Medium-small fruit, soft with good flavor. Vigorous, short, spiny canes.
Polana: Early ripening fall crop, medium-sized, good quality fruit. Vigorous plants. May be too late for far northern Maine and New Hampshire.
Purple Raspberries
Royalty: Late ripening. High yielding, large, round, reddish purple fruit that are soft, with good flavor. Large, vigorous canes with thorns. Susceptible to root rot.
Success: Mid-to-late ripening. Small, dark purple fruit with good flavor. High yielding. Slow spreading plants, with thorns.
Planting and Management Systems
Plant raspberries early in the spring after the danger of severe frost is past (late April to mid-May). Do not allow plant roots to dry out before or during planting. Plants should be set at the same depth or slightly deeper than they were in the nursery. Firm the soil around the roots and water the plants. If one-year-old canes are used, cut them back to a height of four to six inches above the ground.
Red raspberry plants are typically grown in a hedgerow. Crowns should be planted about 2 feet apart in rows that are 8 to 12 feet apart. Choose the wider spacing if you’ll be using large equipment, such as tractors, in the planting. The plants will soon send up suckers from the roots and crowns to form a hedge, which should be maintained at 12 to 18 inches wide at the base.
All raspberries should be grown with some sort of a trellis. This will improve fruit quality, make harvesting easier, and reduce disease problems. Trellises also make pruning simpler by encouraging new cane growth in the middle of the row, rather than just along the outside edges.
For the T trellis, sturdy posts should be set in the row with 3½-foot-long cross arms affixed at a height of 3½ to 4½ feet. The posts should be set at least two feet deep in the ground and anchored at each end of the row. Secure heavy-gauge wire along the length of the row on each side of the cross arms.
DESCRIPTION
LEAVES: Compound, 3 to 5 leaflets, with the middle leaf being the largest. The leaves are coarse to the touch, somewhat rough, and the margins are serrated. The leaves have a pleasant smell when crushed in the hand. The leaves on the 2-year old canes (fruiting canes) seem to become darker and a little thicker before dying off; this will help you determine the first and second year canes from each other.
FLOWER: Quite small, white to pale pink in color, and are born terminally in small clusters. The receptacle consists of 60-80 embryos, which can and often do develop into drupelets. The flowers give off a lot of nectar, which is of course appealing to insects and bees. Although Raspberries are indeed self-fertile, you will almost always see them planted in groupings.
FRUIT: Numerous drupelets, or really just flesh-covered seeds, clustered around a receptacle, which is left behind when the fruit is picked. This leaves the fruit with a hollow center Fruits really only take about 30 to 35 days to form after pollination. One of the time consuming aspects to growing Raspberries it the harvesting itself, as they tend to ripen over a period of days in the fruiting season. You may have to harvest as often as every two to three days. The fruits themselves are easily crushed or damaged, and for that reason, it is best to pick them in shallow baskets. Once harvested, they only remain really nice for three or four days under refrigeration. But despite the hassles, if you have never eaten fresh Raspberries from your own vines, you have no idea how much better they are than the Grocery Store Varieties you buy in the little plastic domes.
CULTIVATION
LOCATION: Raspberries like sunny areas in cooler climates, but actually enjoy part shade in the heat of our North Carolina summers. They will fruit in sun or shade but are not particularly salt or wind tolerant. They are very frost tolerant and can withstand long, cold periods. Red Raspberries need a little winter chill in the 800-1200 hour range. Plants grow best in a slightly acidic soil that have good potassium levels. We have found that our Raspberry plants grow much better with the spring time application of a organic ground cover, which also keeps the roots cooler in our hot summers but tends to keep the grass and weeds at bay. They are not particularly drought tolerant, and will need supplemental watering when the weather is dry and the fruit is developing. DO NOT over fertilize with nitrogen as this results in too much leaf growth at the expense of fruiting. Once established, Raspberry plants take on an over lapping cycle of maintenance with respect to pruning, as the two year old canes are pruned out as they finish fruiting and you work with the newer, one year old canes. All damaged canes should be removed. Expect about the same level of pests and diseases as you have with Blackberries, but you must also count on the competition of both the two and four legged creatures in your area.
CULTIVARS
As you can see from above, there are many, many cultivars of Raspberry on the market today, varying in size, taste, color, shape, and on and on. The problem with ALL of them is that the fruit is so soft and tender, it has virtually no storage potential and needs to be consumed / used within a day or two of harvest. (Raspberries are probably the most often thrown out commodity in an entire Grocery Store for just this very reason).....but that won't be as much of a problem if you grow your own.
Spring / Summer-bearing cultivars produce canes that are biennial in habit (live two years), growing one year and producing fruit the next year.
Everbearing (fall-bearing) cultivars produce canes that bear fruit on the top portion of the current season's growth in late summer to fall (generally in late August to early October). If you leave these canes for the next year, they will bear fruit on the portions that did not fruit the previous fall. Therefore, with Everbearing Raspberries, you can produce fruit in both June-July on the base of last year's canes and once again late summer-early fall on the top of the current season's canes. Pretty cool!
Both our Raspberry Cultivars are Everbearing types.
NOTE: If you prune for as above for a two crop harvest, the spring crop will be small. If you only want one large harvest, then in March or early April, simply prune all the canes back to ground level and you will have a very large fall crop.
We currently offer the following Raspberry cultivars for sale here at Rabbit Ridge Nursery, which are proven to do very well in our hot and humid North Carolina summers.
Click on the Raspberry below to learn more about it.