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 degrees 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.
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