They arrived on the Sound in November 1845, bringing them only those few belongings which they could tie on the pack animals...

Just  as the overall picture of agriculture in the Oregon Territory in 1850 was good, so was life on the Bush farm, which saw expanded cultivation, more crops, and larger harvests... There was always plenty in the Bush household.  Wheat and oats were the principal grains on the farm.  George and Isabella had brought with them the seeds of various fruit trees, which were now beginning to bear fruit.  The storehouse was filled with different fruits and vegetables, such as apples, pears, potatoes, cabbage, and turnips...

Another view by Iris White Heikell in her book
"The Wind-Breaker - George Washington Bush: Black Pioneer of the Northwest"

...Before leaving Fort Vancouver , George made his last visit to Dr. McLoughlin, thanking him for allowing him to plant trees there and to bid him farewell.

"Oh, we will see you again, George," the white-haired patriarch had said, "When you get those seedlings started you will be back for your scions, that I know.  I wish you well in your new home on the Sound, and I feel confident you will be a credit to your country whichever one it might be.

A view by Georgiana Blankenship in her fine old 1914 book "Early History of Thurston County Washington Together With Biographies and Reminiscences of Those Identified with Pioneer Days"

....Mr. Bush, shortly after his arrival, set out fruit and shade trees, the seeds of which he had brought with him from his old home.  Many of these trees grew and flourished and stand to this day, noble monuments to the hardy old pioneer.

A view by Lenore Ziontz

...They carried seeds, farm implements, livestock, and even live trees for their new home in the west. George and Isabella brought along the seeds for cherry, plum, prune, pear, and crabapple trees but they brought small poplar and quince trees with them. George thought that the poplars might be needed as windbreaks and that the quince trees were too lovely and the tarts and jellies made from their fruit too irreplaceable to leave behind.

Bush is not officially given credit for transporting fruit stock.

Lewelling carried the first grafted nursery trees over the Oregon Trail.

In 1847 Henderson Lewelling and family moved from Iowa to Milwaukie, Oregon

...When the next spring came, he (Henderson Lewelling) had secured the cooperation of a neighbor John Fisher for the prosecution of his plans to take the fruit trees. They had procured a stout wagon and made two boxes twelve inches deep and of sufficient length and breadth, that set in the wagon box side by side they filled it full. These boxes were filled with a compost consisting principally of charcoal and earth, into which about 700 trees and shrubs, embracing most, if not all of the best varieties in cultivation in that section of the country were planted. The trees were from twenty inches to four feet high and protected from stock by light stripe of hickory bolted to posts set in staples on the wagon box.  Mr. Fisher soon died. Mr. Lewelling now had charge of the nursery wagon, and decided to carry it through in his own way and time, as he had already been criticized by some of his friends for attempting to haul that heavy load across the plains and over the Rocky Mountains. The trees had to be watered every day if possible, and thus the maximum weight of the load remained the same throughout the entire journey.

According to Alfred Lewelling "There (at The Dalles) father joined with others and constructed two boats to bring the wagons and other goods, as well as their several families, down to the Willamette Valley. 
    "The boats were completed, loaded and started down the Columbia River, about the first of November. They went down as far as Wind River, where they were unloaded and boats used to ferry our cattle and horses across to the north side of the Columbia River, then reloaded and taken to the Upper Cascades, again the boats were unloaded and the wagons set up and hauled to the Lower Cascades. The boats having been turned adrift at the Upper Cascades went bumping and tossing down the scathing current and were captured below. (As the Salem expedition carried no row boats, it has been suggested by later writers that Indians with their canoes were employed to capture the heavy barges.)
    "At the Lower Cascades the boats were reloaded and worked down the Columbia River to a point opposite Fort Vancouver, reaching there the 17th day of November, just seven months from the day of starting. Those of us who drove the cattle down the trail did not get there until the 20th of November.
    "The fruit trees were taken out of the boxes when the boats were ready to start from the Dalles, and carefully wrapped in cloth to protect them in the various handlings, and from the frosty nights."
    Lewelling had now reached the goal of his expedition. He had arrived in the long cherished Willamette Valley with his cargo of precious trees. The story of his journey shows with what matchless energy he persevered in his enterprise, and what infinite care he bestowed upon his trees. 
    He next had to find a home for his family and a permanent lodgment for his traveling nursery. He spent several days exploring the country and on the 10th of December moved his family into a cabin opposite Portland, now East Portland. From here he made another survey of the valley, and finally purchased a tract of land where some clearing had been done adjoining the town site at Milwaukee.
    On February 5th, he moved his family to this place and began the making of a permanent home. The land was densely covered with heavy fir trees, but by a vigorous application of the ax and torch, a clearing was soon made sufficiently large to plant the orchard and nursery. Lewelling's ambition was now fully realized. He had brought his cargo of living trees across the plains and over the Rocky Mountains to the Willamette Valley, the first cultivated, or grafted fruit to reach the Pacific Northwest.  
   About half the trees he loaded at Salem, Iowa, survived the arduous transportation, and were now securely planted in the soil of Oregon. Lewelling's fame and fortune were assured. Emigrants were rapidly pouring into the Willamette Valley and around the Puget Sound, and the demand for fruit trees was unlimited. He was in a position to supply this demand with the choicest fruit trees America could furnish. He had taken the pains to transfer to Oregon the same variety of apples that had proven so popular in Iowa. There can be but little doubt that the superior quality of the apples supplied by his nurseries established the reputation of the Oregon fruits, and helped lay the foundation of the great apple industry of Oregon and Washington. A few years ago, when the writer was touring Oregon, he was shown the locality of the original Lewelling nursery, and he found growing in that vicinity the same varieties of apples he had known when a child in his father's orchard near Salem, Iowa.
    Lewelling, who like his friend, Dr. Marcus Whitman, the missionary, knew the value of the region, was a strong advocate of securing as much of the Oregon country as was possible to obtain by fair and honorable means. He was not, however, one of those who raised the cry "Fifty-Four Forty or Fight". His Quaker training led him to believe there was a better way. He was greatly pleased when the final settlement secured to our country the Puget Sound, for he believed that these waters would some day be a powerful factor in the commerce of the world. Soon after he established himself in Oregon, Lewelling formed a partnership with William Meek, a man from Bonaparte, Iowa, who had crossed the plains the same year, but not in the same train. This firm not only engaged extensively in the nursery business, but organized the Milwaukee Milling Company, and operated several saw and grist mills. At the same time they carried on several other enterprises.
    When Lewelling and Meek were selling trees in all parts of Oregon and Washington, John Lewelling left Salem, Iowa, in 1850, and located in California, buying property at San Lorenzo, Alameda County. Here he started in the nursery business, obtaining his foundation stock from the Henderson Lewelling nursery, at Milwaukee, Oregon. The enterprise was successful. He reared his family here, and his descendants are occupying prominent positions throughout the State to-day. 
    In 1853, Henderson Lewelling sold all of his interests in Oregon to his partner William Meek, and he and his son Alfred moved to California, purchased land in Alameda County, and engaged in the fruit and nursery business. Alfred named the locality Fruitvale. Soon a large population gathered in that locality, and Fruitvale became a beautiful little city adjoining Oakland.
    Henderson and Alfred Lewelling sent out from this place not only thousands, but hundreds of thousands of fruit trees all over California. Again Henderson Lewelling was in no small measure responsible for the beginning of the great fruit industry of another Pacific Coast State—an industry which has brought more wealth to California than all the gold the State has produced. Henderson Lewelling built a fine residence in Fruitvale which in later years was occupied by a Governor of the State.
    After these achievements, and having acquired for himself both wealth and an enviable reputation, he seemed to have reached the limitations of his work on the Pacific Coast. But he could not be content to stand still, and look back upon past achievements. He must still press forward, and be a leader among men.
    About 1858, he conceived the idea of founding a colony in Central America. He had crossed the Isthmus of Panama in 1851 in his travels back and forth to the eastern States. He was much impressed by the mild climate, the cheap land, and the luxuriant growth of vegetation in that semi-tropical climate. He enlisted several others in the project, and in 1859 sold his valuable property in Fruitvale, purchased a ship and all necessary supplies, and he and his two younger sons together with his partners and their families, embarked for Honduras.
    Prior to this, Lewelling had been successful in his every undertaking, but in this project he met defeat. The enterprise was a disastrous failure. He was the principal capitalist in the scheme and he lost heavily. Returning to California, he engaged in the fruit business again; but by this time he had lost his former vigor, and he never regained his former financial standing. A part of the Lewelling estate in Fruitvale was sold to a man by the name of Diamond. This tract was later donated to the city, and is now known as Diamond Park.
     
How many of the original trees carried by Henderson Lewelling from Salem over the plains and mountains to Oregon still survive is difficult to ascertain. There is one tree, however, whose history has been accurately recorded and is worthy of mention here. In 1845, Lewelling planted a cherry pit which sprouted and grew. In 1846, he grafted this seedling with a Black Tartarion scion. In 1847, he carried this tree on his seven months journey to the Willamette Valley. In the spring of 1848 this tree was planted in the soil of Oregon at Milwaukee. In 1849 the tree was sold to David Chamberlain for five dollars. Mr. Chamberlain carried the tree by canoe, down the Willamette River to the Columbia River, then down the Columbia to the mouth of the Cowlitz, thence to Cowlitz landing where Toledo now stands, thence by horseback, seventy miles to Chambers Prairie, four miles from Olympia, Washington. Here the tree was planted and it is still bearing fruit. It is an immense tree now, and three feet from the ground it measures nine feet in circumference. Its limbs have a spread of sixty feet.
    George R. Haines, Curator of the Oregon State Historical Society, in speaking of this tree said: "I stood under its branches in 1853. In 1854 I ate cherries from the tree, and for many years thereafter. In 1895 it bore a crop of forty bushels of cherries. In 1920, the crop was 1200 pounds."
    Moses Votaw, a great nephew of Henderson Lewelling, visited this tree in July, 1928. It was after the cherry season, but he found many dried cherries still hanging to the branches, and many dried cherries on the ground. One of the lower limbs had been removed by a saw. A measurement across the saw kerf showed that the limb had a diameter of sixteen inches. That this little cherry sprout, originating at Salem, Iowa, should withstand the risks of transportation across the continent and the hazards of frequent transplanting, and still live, is a towering monument to commemorate the energy and enterprise of a Salem (Iowa) pioneer, and to this writer a fact stranger than fiction.

More can be found about the Lewellings in this article in the USDA