Raspberries

July 7, 2011    

My wife and daughter just finished picking the first raspberries of the year.  I didn’t see if they came back from picking with red juice stains.  However, they are delicious.  (I snuck a few berries yesterday)  The berries are about three weeks later than last year due to a cool spring.  Five years ago when the raspberries were established five plants of five different varieties were chosen.  I chose based on four criteria; will they grow in a cold climate, berry size, berry flavor, and productivity.  All varieties were from Nourse Berry Farm.

My choice as the best variety is Jaclyn. It is outstanding and it spreads the easiest.  The canes are the tallest of my varieties.  It produces a very large sweet berry, moderate crop size and a spring and fall crop.  There are a few odd berries all through the summer.  It is a primocane beater, meaning it produces berries on the canes the fall the first year the canes emerge.  Most varieties produce primocanes the first year which do not bear, then the following year those canes produce berries.  That fall those canes die and during the year new primocanes grew.    

My second berry choice is a similar but with less yield, smaller berries, and shorter canes.  However, the berries are really good.  The variety may be heritage, but I forget.  Two other choices are just summer bearers and are not my favorites.  Those berries can be small and one spreads faster than it produces average size berries, but they taste good.  They are forgettable and will slowly get replaced with Jaclyn. 

Royalty is my only purple berry.  It was advertised as really sweet.  I didn’t find that to be true.  However it yields for the shortest period of time but is the heaviest bearer. Royalty also spreads less than other varieties which will cause it to be replaced by natural spread of the other varieties. The berries have fair flavor but when looking to make jam or jelly it is a great variety to bring up the berry volume fast to have good jam. 

The first berries were all planted in one single row.  The row is now two rows and I regularly remove primocanes that are growing outside the desired rows.  The berries are kept inside a crude wire structure to help the berries be upright.

Raspberries are a hardy plant but can have insect and disease problems.  My berries have not had significant insect problems or stem disease problems but have had diseases on the berries.  Spray as needed to control problems.  A good neem oil or neem with pyrethrins should work well.  Green Light Neem Oil Concentrate or Green Light Fruit Tree Spray are good choices.  The main problem my berries have had is fruit rot or gray mold, (Botrytis cinerea or soft rot (Ryhizopus and Mucor spp.).  Regular use of Fruit Tree Spray or Neem oil should stop or slow most disease.   Once it fruit rots get established it may be treated with a stronger non organic fungicide Daconil, which is generic or Fung-onil.  Both contain chlorothalonil which must be used weekly and has a pre-harvest interval which should be adhered to.  Neem oil and Fruit Tree Spray can be used the day before harvest. 

Here are some management practices.  They are published in Hort Mag.

1.      Remove dead canes. The presence of empty fruit stems identifies dead or dying canes, as does their yellowing foliage, and roughness of the bark. These canes should be cut low to the ground and removed. (Primocane-fruiting canes that have been left to bear a second year’s crop can be left and will produce a spring crop.) Raspberry canes are less thorny than blackberries, but a leather glove on at least one hand will make handling the canes easy and protect your fingers.

2.      Thin new canes. A vigorously growing raspberry patch will generate an excess of new canes. Some of these will appear at the edges of the patch, causing it to spread. But even within bounds, too many canes left one year will block the growth of canes the next. Good raspberry pruning anticipates not simply next year’s harvest but the harvest of the summer after. Thin the one-season-old canes, leaving the thickest and tallest ones spaced an average of six inches apart.

3.      Weed. With the pruning completed, use a hand hoe or other weeder to clean out grass and other weeds, being careful not to injure the raspberries’ shallow root system. 

4.      Mulch. The first ten feet of row have now been pruned and mulched. Several inches of free-draining wood chips will help the weeds from reappearing. Twin horizontal strings will support the fruit-heavy canes when they bear next summer.

Berries grow different in different environments.  Varieties that do well for me may not do well for you.  They will also grow different in different soil types.

We truly eat all the berries we want all year around.  We bottle them for use during the winter months. Eat lots of a true fruit of the Gods, raspberries.

The Garden Doc