The Berry DisPatch

Newsletter of the Wisconsin Berry Growers Association

October, 2002

Why Not Raspberries?

Brian R. Smith

University of Wisconsin – River Falls

Yes, I know that here is another raspberry article and you dedicated strawberry growers out there are wondering when there will be another strawberry article-well, I do have one planned for the next newsletter!

Fall is a great time to re-evaluate how raspberries could fit into your small fruit business. Many good strawberry growers have told me that they have “tried” raspberries and not found them to be worth the hassle- too many weed problems, inconsistent production, high pruning costs…. However, as I have suggested in the past, most of the time when raspberries did not “work” for somebody there was some other crop that was actually competing with raspberries for the grower’s time and expertise. Could it be strawberries are the real reason for raspberries getting a bad name in Wisconsin? Think about it- which crop comes first when you consider pest control, irrigation, nutrition (if there is time, I will eventually get to the raspberries, but only after the strawberries are taken care of!)

I know of one direct market-fruit operation in the upper Midwest that started with apples (70 acres) and then added fall fruiting (FF) raspberries, strawberries and pumpkins. The owners did the math and actually came to the conclusion that the raspberries were the real profit-maker of the four. About 2 acres of raspberries were originally planted and now there are 9 acres, with plans for possible

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further expansion into summer-bearing(SB) raspberries and maybe winter greenhouse production of raspberries.

Okay, so you’re not convinced- lets look at potential critical factors in success of raspberry plantings.

Labor Issues – Do you have enough labor set up to handle raspberry production at peak times? A large amount of labor is required for late winter detailed-pruning necessary for summer-bearing raspberries. With careful management if you feel this labor is too costly, try using the Biennial Production System (see the April ’02 newsletter) in which half of your plantings produce in any given year and all you do is mow off the canes and narrow the rows- no detailed pruning! Yields can be almost as high as if all the planting were bearing each year if you implement versions of primocane suppression to eliminate competition with bearing canes.

Planting Density/Row Spacing – This certainly depends partly on your tractor wheel spacing, but sometimes keeping an old tractor with 6ft between wheels can be more costly than purchasing a compact used tractor and being able to efficiently use land and plant rows 6-8 ft. apart. Remember, raspberry efficiency is similar to strawberry; up to a point, the more narrow the rows and the more rows/acre the better the yields are and the less chance you will see pest problems. Plants are a costly item in the establishment year, but it does not pay to skimp- the further the plants are apart- the longer it takes to fill the row, the longer it takes to reach maximum production/cash flow, while the more you realize you have a growing weed problem…. Fall fruiting raspberries should be planted no more than 2 ft apart within a row. Closer spacings such as this in an early-planted FF field can produce cash flow the first year! SB raspberries should also be spaced as close although the benefits are not as immediately enjoyed.

Proper trellising – Simplicity is the key in most cases. Few commercial raspberry plantings should ever be considered without a trellis. Trellising helps keep the plants within boundaries so that machinery can travel in between rows to prevent pest problems, reduce fruit losses and allow for easier harvesting. Also, make sure the trellis matches the crop. FF raspberries require trellising even more than SB cultivars because they start fruiting basipetally (from the tips downwards) and are naturally top heavy and flop over. FF raspberries should have easily removable posts in order to facilitate mowing procedures. SB raspberries can have a more permanent post/trellis unless you anticipate using the Biennial System.

Cultivars/Fruiting Type – First decide whether July or a mid-August to October season fits in better to your operation. SB’s should come into harvest right after the last strawberries and have no “frost” and potentially very few pruning issues (Biennial System). FF types fit neatly in with apples or late-season vegetables. Frost is becoming less of an issue as earlier FF cultivars are being introduced. However, to obtain a sufficiently long harvest season, several cultivars are usually chosen and the reality of frost control again comes back as a concern after mid-September. Few if any growers opt for overwintering canes of FF raspberries in order to obtain a light summer crop due to typically poor yields, the potential for winter injury and the need for more detailed pruning. It may just come down to the issue that you want to plant SB types and have all harvesting done by August 1 or that maybe you are so sick of strawberries that you need a 4-6 week break before “braving” it again and thus you choose the FF raspberries.

Whichever fruiting type you choose, the correct cultivar will be the next most important decision you make. Do some background research on the characteristics of the cultivars you are considering; such as disease resistance, winter hardiness, potential yield, fruit quality, cropping consistency, etc. Get a copy of my “Recommended Raspberry Cultivars for Wisconsin.” Next, since you still cannot be entirely sure which cultivars will perform best on your particular site, choose the most promising 6-9 cultivars (2-3 each of early, midseason and late) and trial them on your farm (minimum 100 plants of each).

Site Selection- Raspberries generally benefit from the same soils as strawberries-sandy loams, loamy sands; they will develop fewer diseases problems. However, exposure is even more important. FF raspberries benefit from a warm southerly exposure- the greater the heat the earlier they will bear in the fall and the greater the % of crop you will harvest without frost complications. SB raspberries will benefit from a more northerly exposure if they have protection afforded by a windbreak. SB raspberries sustain the most winter injury from becoming active during mid-to late winter warm spells-northern exposures help prevent undue warming and activity.

Irrigation- It is easy to slip into the idea that the larger the plant, the less you have to worry about irrigation. (Most apple orchards in Wisconsin would benefit significantly from irrigation, but how many orchards actually have or use it?) Raspberries should be drip-irrigated on a regular basis to obtain maximum fruit yield, quality and health! Sprinkler irrigation will be required only for late maturing FF cultivars.

Weed Control- This could be the most important factor in raspberry planting longevity and is the same for strawberries. The preparation and establishment years are the most critical-eliminate the perennial weeds the year before and don’t allow any weeds to gain a foothold in the establishment year; you will be rewarded with many years of minor weed control in most cases! The other great aspect of raspberry production is that there are many more herbicides with greater and longer activity than those available for strawberries. However, with this added flexibility there is also the possibility of greater error. Some herbicide labels for raspberries are not appropriate for raspberries and additionally some appropriate herbicides for raspberries have labeled rates higher than they should be! These inconsistencies can cause major problems in raspberry production.

Examples of inappropriate herbicides labeled for raspberries: Karmex, Solicam

Examples of appropriate herbicides with labeled rates too high (at least at upper range of labeled rates): Princep, Sinbar, Surflan.

Also, consider the fact that tissue-cultured plants in the establishment year are far more sensitive to herbicides than bareroot cane stock.

Marketing/Pricing Raspberry yields are typically lower than those for strawberry but value per pound much higher. Make sure you get compensated appropriately for your hard work. Raspberry prices should be 2-4 times higher than for strawberries. Also, keep in mind, fewer people typically want to go to a pick-your-own raspberry operation as compared to strawberries. Therefore, your greatest business/profit potential is more likely to be in pre-picked markets, assuming you can find a reliable labor force and a large enough customer base.