How the Plum came to California
The California Dried Plum was born when agriculturists brought the famous Petite d'Agen plum from Southwest France to California during the Gold Rush and grafted it onto wild American plum stock.
Over 150 years later, California has upwards of 75,000 acres planted with prune plum trees. With less than 1 percent of that comprising such varieties as Imperials, Robes de Sergeant, Sugars, (and more), the descendant of the original Petit d'Agen still rules the orchard. What makes these prune plums so special is their ability to ripen fully on the tree, pit and all, without fermenting.
The state's greatest dried plum production occurs in the Sacramento and San Joaquin Valleys—acreage that produces more dried plums than the rest of the world combined. Approximately 99 percent of the U.S. supply and 60 percent of the world's supply come from California.
This is thanks to the state's rich valley soil, its long, warm growing season, an abundant supply of irrigation water and an innovative spirit that lets growers tap the latest agriculture practices. Taken together, they present the ideal conditions for bringing fruit to full maturity on the trees, making for maximum flavour, ideal size, fine texture, high sugar content and smooth small pits. This means perfection for California Dried Plums.
Growing and Harvesting
Picking up a pack of prunes at the supermarket or health food shop is so handy that it is easy to forget that those sweet and tasty treats did not get there overnight. The California Prune's long journey from plum to packet is an interesting story and it all starts with a seedling...
In the Orchard
When a California grower plants a prune plum tree, they have a four to six year wait before they see their work come to fruition. Even then it takes a tree from 8-12 years to reach full production capacity of 150–300 pounds of raw fruit each year. From that point onwards the tree will have a commercially productive life of about 30 years, yielding the fine quality fruit that we know and love.
From Winter Rest to Summer Sun
The prune plum tree is deciduous, losing its leaves and being dormant during the winter months. This quiet time for the tree offers the grower an opportunity to prune it which regulates the shape to maintain a healthy growth pattern and control fruit size.
With the arrival of spring 75,000 acres of California Orchards are blanketed with white fragrant blossom, however this lasts little over a week and the petals soon fall to the ground. Over the next few months the orchard will turn a deep pink as new fruit forms and leaf buds burst open.
A California summer is typically very warm and dry so growers irrigate the orchards to keep the trees healthy and the fruit quality consistent. The trees are given just the right amount of water to top up what is available underground.
By mid-August, the orchards are ready to be harvested, this task typically takes about 30 days. Prune plums are ripened on the tree so growers determine the optimum harvest time by checking fruit firmness and sugar content.
In the past growers smoothed and softened the ground underneath the fruit trees and allowed the plums to drop before collecting them to take to the dehydrator, this method took 3 or 4 pickings for all the fruit to be collected. Once, in 1905 one farmer thought it would be clever to bring 500 monkeys from Panama to pick his fruit instead. He organized the monkeys into groups of 50 and set them loose in the orchards—with a human supervisor, but while the monkeys were good at picking the prune plums, they were even better at eating them so needless to say this method did not catch on!
Today harvesting is largely done by machines which are much more efficient and controllable. A mechanical shaker takes hold of the tree's trunk or main limb and gently shakes the fruit onto a fabric catching frame underneath. From there the plums are quickly conveyored to pallets ready for the dehydrator.
Dried, Packed and Ready for the Off
Processors waste no time in transferring the freshly harvested fruit to the dryers where three pounds of fresh fruit become one pound of prunes. The plums are washed thoroughly and placed on large wooden trays, ready to be dehydrated in a sequence of scientifically determined, automated and hygienically controlled operations. Temperatures are strictly controlled in order to maintain the uniform high quality product for which California Prunes are renowned.
Following dehydration, the new prunes are taken to state-of-the-art packing plants. Here they are inspected, graded for size and stored before their final processing and packing. Prunes store best at 21% - the point at which they are known as 'natural condition dried plums' so post-harvest drying aims to reach this level. The prunes remain in this state in cool storage facilities until they are needed to fulfil customer orders.