By Nancy Hawkins
UCCE Master Gardener
As I researched information on planting bare root fruit trees, the words of the county’s fruit and nut crop advisor came to mind. He said to a new class of Master Gardeners, “Consider carefully your motive for planting fruit trees in a home garden. They require lots of work year round; irrigating, pruning, harvesting and managing pests.” Keeping this advice in mind, let’s look at the benefits of growing your own fruit.
The San Joaquin Valley is the most important area in California for the production of fruit and nut crops like almonds, apples, cherries, figs, kiwis, nectarines, peaches, pears, persimmons, pistachios, plums and walnuts. Why? There are two main reasons; soil and weather. Our relatively flat valley is blessed with some of the best soils in the world. Most of the soil is made up of alluvial deposits from several California rivers, making the soil rich for agricultural planting. Maximum temperatures can reach over 100°F in the summer, but day and night averages even out to 84°F. Winter temperatures average 45°, but can drop below freezing (as citrus growers know!) for short periods of time. These temperatures are ideal for growing fruit trees.
What to consider when choosing a variety of fruit tree to plant? Some items include winter chill and pollination requirements, space available in your yard, and, of course, most important, personal taste. Winter chilling is the number of hours below 45°F during the fall and winter. Chilling influences bud break (flower formation), fruit set and development. Most varieties require 200 to 2000 chilling hours to break dormancy. For example, apples, pears, and cherries have the highest chilling requirements (900-1,200 hours), while peaches, plums and nectarines are a little lower (600-900 hours). Grapes, pomegranates, figs, persimmons and citrus need very little chilling (100-400 hours). Chilling requirements should be listed on the fruit tree label or check the variety you are interested in on University of California Ag and Natural Resources (UCANR) web site cetulare.ucanr.edu. Our part of the valley averages about 800 chill hours.
Pollination is the transfer of pollen from flower to flower on a tree. Many fruit trees are self-fertile, meaning they do not require a partner for pollination. Others need another variety of the same species close by in order to bear fruit. Check the pollination requirements for each tree you want to plant. Again, pollination requirements should be on the tree label or visit ucanr.edu/sites/UC_Master_Gardeners/UC_Gardening_and_Pest_Info/
Would you like to grow fruit trees in your yard, but think you do not have enough space? Put that fear aside. You can grow four fruit trees in your yard in the space of one commercial tree. One tree of each variety is generally sufficient to provide for a family’s needs. Trees need a location with at least 6 to 8 hours of sun each day. Check the mature width of each tree you want to plant to determine the total number of standard trees that will fit into your yard. In addition to the space needed to grow to full width, allow 3-4 feet between trees to allow for access and air circulation, needed to ward off fungal diseases.
Growing trees in a limited space poses interesting challenges, often solved by growing in containers, by planting dwarfs, by choosing multiple varieties per tree, or by using “high density” plantings. Fruit trees are grown on standard or dwarfing rootstock and can be maintained at a much smaller size that a standard fruit tree (20-30 feet at maturity). Depending on the rootstock used, fruit trees can be kept as 5-foot “miniatures,” 15-foot “dwarves” or to any height in between. The smallest fruit trees are suitable for growing in large tubs on a patio or deck.
To keep trees at a “picking height,” judicious and severe pruning when the tree is young is the key. When planted, the main trunk is cut back to knee height and 3-4 branches are selected and cut back. In May, these same 3-4 branches are cut back by one third. All other branches are removed. In August, the same branches are cut back again by one-third. The result is a tree approximately hip high after the first growing season. After a couple more years of training to get 6-8 branches per tree, the tree is kept at a short height for the rest of its life by pruning. The home grower decides the ultimate height of the tree. The goal is to keep the tree around 8 feet tall.
“Fruit cocktail trees” are multi-budded or three-in-one trees. In this case, the wholesale nursery chooses popular or appropriate varieties and buds them on the same rootstock. Each main scaffold is a different variety. The trick is to keep an eye on these trees and heavily prune the variety that starts to dominate the whole tree. Otherwise, you will end up with a single variety tree. The same pruning for size rules apply to these “cocktail” trees.
Plant three trees in the same hole? This “high density” technique promotes planting three trees in the same amount of space needed for one full-sized tree. You can plant the trees in the same hole spacing them 18-24 inches apart. Plant the three in a triangle pattern with trunks slanted outward and pruning back inward-facing branches. Closely planted trees don’t grow as large as trees spaced farther apart and have a better chance of cross-pollination. You can plant varieties of the same fruit that ripen at different times or three completely different fruit trees. This planting technique is a good choice if space is limited. Again, pruning to limit size is important.
January and February are the best months to plant your home orchard, whether it is one tree or a dozen. Trees are available in pots or bare root. Bare root fruit trees are grown in fields of loose soil and harvested with giant machines that gently lift and pry them from the ground, leaving their root system splayed out like an upside down canopy. The trees are kept in cold storage to keep them dormant before distributed to retail nurseries. They are sold without soil or pots and are less expensive and easier to plant than container plants. The roots dry out quickly, so they need to be planted as soon as possible after purchase.
No matter how you plant, the goal is to be able to prune, spray, thin, cover, and harvest without using a ladder. So, put away your fears of growing fruit trees, pick a couple varieties for a trial, and enjoy the luscious fruits of your labor.
The UCCE Master Gardeners will be available to answer your gardening questions each Saturday at the Visalia Farmer’s Market in the Sears parking lot from 8 to 11 a.m.