Growing Raspberries

internet photo

There is nothing better than wandering across the grass, climbing over the little rabbit fence, and reaching for a plump, juicy, sun-kissed raspberry. If a little juice runs down my chin when I bite into that luscious berry, so much the better. Add to that the fact that raspberries are highly nutritious - packed full of Vitamin C, fiber, and antioxidants - and you just might have the perfect back yard fruit.

Raspberries are relatively easy to grow, and with a little care, you can have home-grown raspberries for a good long time. There are two types of raspberries: summer- bearing, and ever-bearing or fall-bearing.  Summer bearing produce one large crop per year in the summertime on last year's canes and ever-bearing or fall-bearing produce on both last year's canes and the current year's growth, so you can harvest two crops, one in the summer and one in the fall.

Summer-bearing varieties usually begin producing in early summer and produce for about two to four weeks. Fall-bearing varieties typically begin producing in mid-summer and produce up until a killing frost, or in the case of this past year when a killing frost came very late in the season for us, until the shorter days of autumn and winter in the north country discourage further fruit set.

Raspberry roots are perennials, which mean they come back year after year in their hardiness zones. The canes, which grow from buds on the root, are biennial, which means each cane lives for two years. Some raspberry varieties produce fruit on the canes the first year of growth; others produce fruit only on canes that are two years old.

Those which produce fruit on the canes the first year are called "primocane" raspberries, and are also identified as "fall-bearing" because fruit ripens late in the season. You can harvest fruit from those varieties the first year of planting, the first crop generally in July or early August, and the second crop later in the fall.  The first year canes become "floricanes" or second year canes the next growing season, and they will produce a crop again in early to mid-summer, but it is usually a marginal crop at best. Many growers prune all the canes down in the fall so that the next year's growth is all primocane, helping the raspberries to produce better.

An old standby primocane variety for zone 4 and warmer is "Heritage". Heritage produces large crops of good-sized berries that are good for eating fresh, freezing, canning, jams and jellies.  "Anne" is a yellow-fruited variety that has a hint of an apricot taste. Anne is good for eating fresh and freezing, but is not the best for canning or jams and jellies because it does not retain a nice color when heated. "Polana" is similar in taste and color to Heritage, but the fall crop ripens several weeks earlier, so it may be a better option for those areas where killing frosts come earlier in the fall. Polana is rated hardy to zone 3, so it is one of the hardiest of the primocane raspberries. Another earlier ripening variety hardy to zone 3 is "Autumn Britten".  Other zone 4 hardy varieties include "Polka", another Polish variety similar to Polana; and "Joan J", an early producer that has the distinct advantage of being borne on a thornless bush. "Caroline" produces a nice, large berry with an intense flavor. I find that this variety, while rated for zone 4, needs to be in a very sheltered location or have the root mulched in the winter. "Himbo Top" produces very large, deep red berries that hold their color better than most varieties. It is a favored variety for farmers' markets and roadside stands for that reason.

"Heritage" raspberries (internet photo)

"Anne" (internet photo)

Raspberry varieties which produce fruit on two year old canes are called "floricane" raspberries. The first year of growth on the canes will be only vegetative - there will be lots of green leafy growth, but no flowers or fruits. The next year, those canes will bloom and set fruit, while new vegetative canes begin to prepare for the next year's fruits.  There are more zone 4 and colder varieties of floricane raspberries than there are of primocane, and the nice thing about those varieties is that they come in early, mid, and late season fruiting, so you can extend your growing season significantly with a selection of several varieties.

Boyne is an early season floricane variety that is hardy to zone 3. It produces good amounts of nice, sweet berries that make excellent jam.  They are not a real firm berry, so must be handled carefully in picking and storage. Prelude is another early season variety hardy to zone 4 with excellent flavor, but also not a real firm berry.

"Killarney" (internet photo)

Killarney is an early-mid season producer that is a little finicky about growing in colder climates. I like the fact that it has very sturdy canes that stay upright even when loaded with fruit, making the berries easier to pick (and I am all about anything easy). Killarney has been around since the early 1960s, and while it is a zone 4 hardy variety, it has done well in my zone 4 but sometimes zone 3 climate. It does benefit from a protected location.

Latham is a North Dakota favorite and is really the workhorse in my berry patch. It is a mid-season fruiting variety that was released by the University of Minnesota in the 1920s and has been a favorite of home gardens ever since. The fruit is medium size and a light red that turns a deep burgundy color if overripe. Lack of cohesion of the drupelets (the little round balls that cluster together to form the berry itself) is a problem with Latham, but for jams and jellies, which are excellent when made from Lathams, that is not a problem.

Nova is another mid-season variety that was released from a breeding program in Nova Scotia in the early 1980s. Nova is tolerant of both extreme cold and heat, reliably hardy to zone 3, and is a heavy producer of medium to large red berries that have a longer fresh storage life than many other varieties. It also has the advantage of having fewer thorns than most varieties.

Encore is a late mid-season producer of large, firm red berries excellent for canning and freezing that grow on sturdy, nearly thornless canes. Now, if you have ever picked raspberries, you have a pretty good idea of why I am telling you about thornless and nearly thornless canes. While I love my Lathams, I hate that I have to pick those microscopic little thorns out of my finger tips for days afterwards.

There aren't any red raspberry varieties that are reliable producers for late season summer bearing in northern climates. Royalty is a purple variety that does ok in protected areas of zone 4, producing large, purple berries in August. The bushes are very prolific and will need trellising to stay upright.

Black raspberries are not as hardy and will need winter protection in anything colder than zone 5. Black raspberries should be planted separately from red and yellow varieties, as they are a closer relative to the wild varieties and tend to be more susceptible to pests and disease. Jewel is one of the hardiest black raspberry varieties.

In the next blog installment, I'll write about planting and care of raspberries.

internet photo