Raspberries


Experts have long warned that weeds may compete with cultivated crops for nutrients and water.

But now research by a team from Washington State University and the United Kingdom has found that weeds may reduce the amount of plant-based nutrients in raspberries, according to a news release.

WSU weed scientist Tim Miller worked with fruit researchers in the United Kingdom last summer on a series of trials that examined weeds and herbicides and their relationship to plant-based or phytonutrients.

The UK team had already developed a method to measure the amount of several compounds in raspberries and black currants, two fruits that have been dubbed superfruits because of large amounts of antioxidants.

The 2012 trial in Scotland linked some hard-to-control weeds, such as broadleaf dock, fireweed and quackgrass, to reduced sugar, vitamin C, color and juice content in the berries.

Tim MillerCourtesy Washington State UniversityWashington State University weed scientist Tim Miller will travel to Scotland to work with colleagues on trial gauging the affect of weeds on raspberry and black currant nutritional content.

And the trials will be repeated this year to determine whether environmental responses during 2012 may have affected the outcome or whether the quality factors respond the same two years in a row.

“A better understanding of the potential effects of management decisions will give growers one more tool to improve not only the yield of their fruit, but also the quality of those fruits for consumers,” Miller said in the release.

 

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After last week’s post on raspberries, I received several phone calls and emails wanting to know how many a family should plant.  Obviously this is an almost impossible-to-answer question with all the variables.  But we hope to clarify the answer somewhat, so let’s give it a shot.  It starts with how well do you like raspberries if they were always available?  Most people say they love fresh raspberries because they only get them a few times a year.  But if you had them to eat anytime you wanted from mid July thru October would you calculate your weekly consumption as a little less than you first thought?  How about the other members of you family, are they the same?  I have a grandson that will pick and eat every Saturday until he can’t eat anymore.  The next week he is at it again. He is a real consumer and we can easily calculate what to grow based on his intake! The next question is do you want enough for fresh use or do you also want to freeze and can for use year round? How big is the family etc.  If canning them, are you wanting extras for gifts? 

The next issue is what your cultural practices are.  The more consistent you are with water and nutrient application, the better and more consistent the crop.  We recommend starting a row using 1 plant per 18”.  We also put a ½ gph dripper on each plant.  This works good with our clay soil, however if yours is sandier you will need to space drippers closer and water more frequently. We try to keep the width of the row at its base 12”-16” wide and the drippers will water about this area, inhibiting suckers from growing in the path.  If you need a few more berries you can allow your row to get a little wider without adding plants or increasing row length.  We will assume that you are adding compost and trying to improve the soil each year for maximum yield.  From my experience with these parameters you will get a good crop the first year, a very good crop the second year and reach maximum potential yield from the third year on for many years if maintained. 

 For the average family of four that will eat raspberries all the time you would want to grow 10’-15’ of row or about 7-10 plants.  This will give you enough to always have for fresh eating and be able to share with some neighbors.  You will also be able to freeze some extras, make milkshakes and an occasional pie.  Twenty to forty foot of row is for the serious family that makes their own jams etc and wants to do canning, freezing and other food storage for the year.  This length row will supply enough to have pie whenever you want, share with neighbors, can a dozen ½ pints in a picking and still have some for smoothies.

 In the warmer weather, raspberries, once pollinated, ripen quickly and we suggest harvesting twice a week.  You can harvest weekly but some berries will be over ripe, sweeter and losing the “tartness”. These are good to mix into making preserves, smoothies etc. By later in fall say first of October usually once a week is sufficient. We feel a properly cared for row of raspberries will provide more fruit and a better return per square foot of space than any other fruit crop.

 To freeze raspberries, place on a cookies sheet on the counter and let dry for an hour. Then put into the freezer on the cookie sheet for a few hours or overnight.  Once they are frozen then put into freezer bags or freezer jars.  If you put them direct into freezer bags you will end up with one frozen chunk that is then harder to use later.  Do not wash or rinse berries before freezing or storing.  Only rinse right before using or they will get mushy and not keep long.

If you have read previous posts you know that we only grow ”Fall” or “Everbearing” type raspberries.  If not click here for a discussion of the differences and why we only recommend these.   Raspberries are an excellent and profitable crop for most parts of New Mexico.  The basic difference on our recommendations is when they start to produce and quantity per foot of row.  We grow these as a row and keep it to about 12-16” wide at the bottom. This gives a row 30-40” wide at the top or picking area.  If left to grow wider it becomes cumbersome to harvest, so dig any suckers out that are past this area and replant to fill in bare spots in the row.

This year’s early and warm spring was definitely a boost to the raspberries.  Our first berries on Polana were July 4th, Autumn Britten July 10th and Polka July 15th.  This is approximately 3 and in some cases 4 weeks early! 

Autumn Britten – good and early- any location

Heritage – an older variety, sturdy and consistent starting later than Polana or Carolyn

Carolyn – Interchangeable with Polana south of I-40 Albuquerque, Los Lunas, Belen

Polana – Best north of I-40 Santa Fe, Cedar Crest, Taos, Estancia      Available

Polka – Smaller sturdier canes flavor similar to Polana,   I-40 area and northern climates     Available

Anne – Consistent yellow raspberry, slightly less production than reds

Fall Gold – Same as Anne, good all areas     Available

The size plant is also a determining factor in getting a good start.  Tissue culture plants are often promoted as disease- free perfect clones and they are.  However they are usually very small, greenhouse grown with minimal root development in 2” peat pots.  If you do keep them alive you will lose at least a year in getting them established.  They do not field plant and adapt well to our conditions.  If you are purchasing bare-root get a 2 year plant not 1 year or else buy a minimum 1 gallon container plant.  These will have the root development to stand the transplanting process. 

One of the debates in growing raspberries is whether or not to use a general or “high” Nitrogen fertilizer on them. One group says you shouldn’t use as this promotes leafy plant growth but not berries which need potassium.  The other group says early fertilization with Nitrogen gives better plant growth and a larger plant with more canes will provide more fruit.  We tend to agree with the later.  I feel the bigger and better shape our plants are in, the better total yield will be.  Also I think this helps to keep production up during hot periods.  But probably the biggest benefit is a taller plant means less bending to harvest and I’m all for that!

We recommend fertilizing using an OMRI listed liquid fish based solution and should continue from the end of April through the end of June.  When you start seeing flowers is the time to quit Nitrogen application.  We then recommend a 2” layer of compost be added in the winter after you have cut the canes down.  This allows the winter snows and rains to help soak it into the ground and also gives some insulating protection to the shallow roots.  Spread 8-12” wider than your row on each side since that’s were many of the roots actually are located.

                 Below is a simple recipe for raspberry jam. Use straight or add other fruits for unique flavors.

 Yield: about 6-7 half-pints

1 quart crushed red raspberries

3 ½ cups sugar

1 pouch liquid pectin

Combine raspberries and sugar in a large saucepot.  Bring to a boil over high heat, stirring until sugar dissolves. Stir in liquid pectin. Return to a rolling boil.  Boil hard 1 minute, stirring constantly. Remove from heat. Skim foam if necessary.  Ladle hot jam into hot jars, leaving ¼” headspace.  Adjust 2 piece caps.  Process 10 minutes in a boiling-water canner.

As we start our third growing season at Road’s End Farm it is time to write about some of our observations and results with the many types of fruiting plants that we grow.  As you know our mission is to develop and promote varieties that are suited to culture in the central New Mexico mountains and similar locales.  We want you to be successful by helping you choose varieties that will profitably produce for you.  Our method is simple in that we take our best educated guess from years of growing, listening to others experiences and add some of the latest varieties to the mix.  We then grow these and see which do best or in some cases do poorly.

Of course results may vary depending on the care, location, microclimate etc. that you give a certain plant.  In those cases we will make recommendations for location and culture.  Our plantings are not babied as you might do at home. They are planted in the field with no shade and treated as a commercial crop would be.  In many cases the planting stock we have purchased has been very small, maybe suitable for a 4” container or was a 4-6” bare root plant.  Such is the way of dealing with new or rare varieties, they just may not be available in a size we would prefer.  Often is the time we felt a larger plant would have survived or thrived whereas the smaller one could not adapt. We will discuss these possibilities as we go through our series of posts.

For those of you more detail oriented, the soil ph at our farm is 8.2 which is considered very alkaline.  Our water comes from fractured limestone and also has a high ph and is very “hard”.  February 2010 recorded minus 34f and summer 2011 recorded a high of 102f.   Most research on “hardiness” of plants is focused on the coldest temperature they can live with and very little research has been done on the warmest temperature they can take.  When we make selections to trial we find ourselves choosing from varieties that may do well in the upper great plains or in Russia’s colder areas. In the case of heat we will discuss it when it applies.  I hope to be able to cover at least 1 fruit type a week in an informal and unscientific manner, but this time of year is always short on “spare writing” time so don’t hold me to it.

On a recent trip to Lowes early in the month, I was confronted by a large display of berry plants strategically situated in the main aisle.  As a former retailer I was extremely impressed.  To say the least, the packaging cups were unique and a new ”invention”.  I was drawn to the

Raspberry cups

graphics which had top notch clarity with vibrant colors.  The shipping boxes were designed to convert to a point of purchase  display.  The product (plants)were tissue cultured and consistent sized.  All in all this product kit and its components were first rate.  I’m sure thousands of hours of design, testing and prototyping went into it and I wouldn’t be surprised if it wins a “Product of the Year” award.

However as a grower and nursery owner, I was extremely dismayed to see this.  Not from a competition point of view but from the knowledge that probably every one of these plants will soon be dead.  The customer will have lost their money, but worse,  will be left with a bad taste in their mouth about growing and supplying their own food. 

Raspberry display

Often in the retail nursery world but especially in the big box arena,  it’s a race to see who can get the first sales of the year.  It’s all about product turns and dollars generated per square foot of selling space.  I receive copies of the trade journals for the Nursery industry and it is estimated that 25% of the vegetable plants and flowers purchased in the spring season will be repurchased since they were planted too soon and lost. 

Mind you I am not against the quality of these plants or their appearance.  My complaint is they are being promoted to an unsuspecting consumer to plant out now.  It is fully 2 months too early for these to be planted outdoors in Albuquerque and 3 months too early for the East Mountains.  To have a chance they would need to be babied indoors and repotted into a larger container. When the weather gets warm enough, they would need to be hardened off for at least a week.  This entails taking them outside on warm days, keeping in the shade, gradually exposing them to longer periods of direct sun and bringing them back in a night.  I notice that Lowes was keeping them indoors, not in the outer garden section.

A plant such as a raspberry can take -10 degree temperatures when fully dormant. However, it is most susceptible to damage or death from freezing when it just budding out new leaves.  These tiny, young plants are not near as tough as an older established plant (which is also susceptible to frosts).  At this point it can suffer damage at just a little below freezing and probable death at 25-29 degrees.  What are the chances we will see these temperatures before spring or the frost free season beginning?  I am not a real gambling man but I would wager about 100%.  Or to say it another way,  if you buy these plants and plant them out they will die! 

This is not the same as planting out bareroot stock which is still dormant.  We do not use greenhouses or force our plants in any way. They are grown here and come out on their own when Mother Nature tells them it is OK.  I know its tempting to want to get some green going after a bleak winter, but your patience will pay off in live plants that perform for you and in a monetary savings also, if you wait until the appropriate time.

The last few Saturdays have been exceptionally warm and gave us a chance to do a little catch up work.  Amazing the things you need to get done in the fall but never quite get to.

For us one of those things is adding compost to our berry rows. 

Dormant Raspberries

In theory the compost  can sit all winter and the melting snows will carry the nutrients down to the roots where they need them for the new spring growth.  Let’s hope we haven’t missed out on all the snow for this year!   February is a good time for cutting down Primocane, also known as fall-bearing or everbearing raspberries.  This is easy since you cut all the canes down, unlike summer bearing where you only cut the 2 year old wood.  I like to leave about 2” above ground as I feel the sun will rapidly callous off the cut and prevent any possible infections at the site. 

Raspberries after cutting canes

This is just my feelings, no proven fact.  It was surprising to see just how green they were this year when cutting.  It makes you think the warm weather is working on them.  Cutting all of the canes makes it simple to add compost.  We are trying to put on a one inch layer in about a foot  wide band. 

Adding compost after cutting canes on raspberries

I would like to go about 18-24” wide but good compost is always in short supply.  Probably the reason gardeners call it “Black Gold”.  The batch we used was 2 years in the making and we used about 6 large wheelbarrow loads per 100 foot of row length

 Last week Matt and I took a short road trip to Alcalde, NM. to attend a workshop on Jujubes.  A tiny hamlet on the road to Taos, just north east of Espanola, it is home to maybe 100 families.  It is also home to the NMSU Sustainable Agriculture Science Center.  At this location some research has been done into different fruit varieties in an organic growing situation.  Mostly this has been trials with blackberry and raspberry in 2003 thru 2006.  After that several varieties of Jujube were planted and monitored. One of the interesting things is that even though the location is 90 miles north of us the weather and temperature parameters are almost identical to our location.

The fruit production there is now under the care of Dr. Shengrui Yao. She received a M.S. in Horticulture/Pomology from Beijing Agricultural University and her Ph.D. in Horticulture/Pomology from Cornell University.  She hosted this workshop and tasting event for about 40 growers, gardeners and other government agency employees.  Shengrui is the perfect person to teach about this rare and unusual fruit from China.  She has the unique perspective of having been raised with a fruit that many in the western world have never even heard of, much less tasted.

 

Even with most picked this jujube tree's branches are bending under the fruit load

The Science Center has an orchard of about 40 trees of maybe 10 varieties that are 6 years old. They have just planted 100 young trees, 25 each of 4 varieties. She is trying to get grant money to fund research for these as a commercial crop for New Mexico and seems to be the only person at any university or research facility in the U.S. that is studying them.   There are about 700 cultivars in China today, however there are maybe only 40 in the United States.  With relations and import rules being what they are it is unlikely that we will be seeing new cultivars anytime soon.  The good news is that many of the varieties here are every bit as good as any of the commercial crops in China, so we may not really need any new types.  Another interesting note is there are no developed hybrids of Jujube, all named varieties are cultural selections. 

Our main purpose for going to the workshop was the tasting session.  Not only did we hope to try some varieties we don’t have, but also to test them in different stages of development to see where

Jujube in various stages of ripening, the side facing the sun turns mahogany colored first

is the ultimate ripeness for fresh eating.  More about that later.  The jujube is not really broken into classes and there are many ways it could be.  For example some varieties are good only for fresh eating, some only for dried and some work for both.  Another way is the fruit shape.  There are elongated, oval, round, gourd, teapot and apple shapes. However I think the best way to classify them might be by maturity: early, mid and late season varieties.  Some of the late season varieties require a longer growing season to mature than we can provide in the mountains.  Albuquerque or further south like Los Lunas would be fine for them though.

Even though jujubes have been cultivated in China for more than 4,000 years their use on the mainland is changing. In 1990 almost 90 % of the jujubes were sold as dried fruit. That has changed to 60% dried, 30% fresh and 10% processed.  This may be in response to the cultural changes that have happened in China more than the fruit’s development.  As China gains a middle class more people have refrigeration and so don’t require a dried product for storage and also more have a disposable income to buy a processed product.

For our purposes here inNew Mexico the benefits to growing the Jujube are many.  I won’t say that they thrive on neglect, but they are hardier than many fruit trees.  Once established they are very drought tolerant.  The bright glossy leaves are like citrus in that they hold in moisture and seem to have a shiny, waxy coating. 

Jujube trees have light branching. This one has good horizontal branches

They like our alkaline soil which most fruits do not.  The amount of heat they can tolerate seems to have no upper limit.  We know they are cold tolerant to -25f and just have not been really tested past that point although I suspect they can live way below it once established.  Most varieties are self fertile but will set a larger crop if you have two and that is what we are recommending at this point. They flower very late and avoid any freezes so you always get a crop. No known New Mexico pests or diseases.  Minimal to no pruning required.  This is about all you could hope for in a fruit tree!

As for taste: most have a sweet apple-like flavor and texture with a hint of almond aftertaste.  The fruit is not quite as juicy as an apple and of course if dried it is different altogether.  It is also called the Chinese Date because of the size and appearance when dried, however they are not quite as sweet or  gooey and sticky as palm dates.

I think if the United States got behind this as a commercial crop, our plant breeders could improve jujubes the way the crabapple was changed to modern grocery store apples.  In 30-50 years we could see a new fruit crop completely.  After all the blueberry got it’s start that way after WWII and now is a major crop and staple item in our diet.

See The Upcoming Part 2 for Tasting and Variety pictures.

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