How and Why to Grow Your Own Fruit

Articles: How and Why to Grow Your Own Fruit

Contributor

Dr. Rachel Spaeth

Topics: Growing for Biodiversity, Sustainable Gardening

Summer 2024

Throughout the Pacific Northwest and beyond, gardeners and landscape professionals regularly wrestle with the decision as to the kinds and quantities of plants they will add to their outdoor spaces. While physical attributes and preferred growing conditions are major factors in our choices, conscientious goals such as being climate-aware, supporting wildlife, facilitating long-term sustainability, and beautifying the landscape also guide our decisions. Another consideration that is sometimes overlooked is choosing plants for their deliciousness. There is nothing quite like the taste of freshly harvested fruit—to enjoy yourself and share with local fauna. Fruiting trees and shrubs can serve as wonderful points of focal interest in the landscape. Plus, by choosing non-commercial cultivars, you can help to preserve genetic diversity and bolster collective food-security in our ever-changing ecosystems.

Choosing the best fruits for your location

While commercial cultivars (specific varieties of fruits that are readily available to the public through distribution points like your local grocery store) like the Granny Smith apple (Malus domestica ‘Granny Smith’) have their value, there are many other remarkable kinds of fruits to consider for the home landscape. These include wonderfully delicious options that are not suitable for mass distribution due to a variety of reasons including their short shelf life, uneven ripening, a tendency toward blemishes or imperfections, and the time required to harvest a crop.. These types of varieties may show up at local farmer’s market, community supported agriculture (CSA), or farm-to-table locations, but they are unlikely available in your supermarket and definitely worth growing.

Aside from assessing specific varieties, there are also many other factors to consider when choosing the right fruit for your space—including climate, site conditions, maintenance needs, pollination requirements, necessary chill hours if any, fruit use, and pests or diseases. In relation to climate, you will need to compare your area’s minimum temperatures and number of chill hours your site accumulates to the needs of the fruit you want to grow. When fruit ripens and how long it takes fruit to be ready for harvest is also important to make sure that the length of the growing season and the fruit you want to grow are compatible.

Chill hours are the amount cool temperatures required for a plant to set flowers and fruit. The number of chill hours required for reliable fruit setting varies depending on the cultivar of fruit. The method for calculating chill hours can be done in several ways: total hours below 45°F (7.2°C), number of hours between 32 and 45°F (0 to 7.2°C), or a dynamic model that considers the number of hours erased by daytime temperatures exceeding 70°F (21.1°C). I like to think of it like a game of Connect Four; chill hours are accumulated by cool temps adding the round pieces onto the gameboard. When a warm temperature spike occurs, it is similar to someone releasing the spring on the bottom of the board, and all the pieces come pouring out. In the Pacific Northwest, we often experience those warm temperature spikes in the winter, which can adversely affect the ability of some trees and shrubs to reliably set fruit. If you want to know what your chill hours are, a handy online tool was designed by the University of California, Davis’ Fruit & Nut Research & Information Center (FNRIC), link in resources below.

After you’ve narrowed down your choices of fruits by chill hours, it is important to consider the nano-climates of the space you intend to plant. Nano-climates refer to the specific attributes of sunlight, exposure, water availability, and temperature. Watch how the sun moves and changes over time in your space. Will the plant receive cool, early morning sun or hot afternoon sun? Is there a deciduous tree nearby that will provide some shade in the summer, but not in the winter? Is your space sheltered from the wind by a fence or wall? Will a wall, driveway, or sidewalk radiate heat or increase the soil temperature where you intend to plant? Will it be planted in a space that experiences a deluge of water from runoff of impervious surfaces? What is your soil type? All these factors can play into making the most informed choice for your space.

Understanding grafted and own-rooted plants

As you begin to look into fruit plant varieties, you will encounter grafted and own-rooted plants. For the most part, fruit trees are grafted. Grafting is the process of taking a stick from a delicious tree (the scion) and adding it to the rootstock of another cultivar. The scion can either be a stick with several buds that is inserted into the rootstock (cleft grafting or whip grafting), or a single bud that is added to the side of the rootstock (chip or t-bud grafting). The scion retains the genetic integrity of the parent material, and its delicious attributes while the rootstock provides strength, resilience, and sometimes even an ability to overcome adverse soil conditions.

Some rootstocks are chosen because they will influence the overall height of the tree. They are referred to as standard (full-size), semi-dwarf (2/3 the height of standard), or dwarf (1/2 the height of standard). Most nurseries will report what type of rootstock was used so you will know what height to expect when your tree matures. Some fruit trees can be “own rooted,” which means they are not grafted onto a rootstock. This is frequently true of fruits like figs (Ficus carica), olives (Olea europaea), pawpaw (Asimina triloba), and feijoa (Acca sellowiana). Berry bushes are typically own rooted as well.

Getting the most out of your fruit

When growing fruit, it is important to understand that not all fruit trees are self-fertile, which means they can create fruits by themselves. Some fruits are self-incompatible, which means they require a nearby tree of a different cultivar that has an overlapping bloom period. The act of transferring pollen from the stigma to an anther by a vector like wind, bird, bat, or insect is called pollination. The plant that donates the pollen is called the pollinizer. Many apples (Malus domestica), apricots (Prunus armeniaca), cherries (Prunus spp.), avocados (Persea americana), and plums (Prunus salicina and P. domestica) require a pollinizer. Even if a pollinizer is not required for a fruit set, a vast majority of fruits benefit from having pollen donated from an outside source.

Once your fruits start to form on your tree, it is recommended to thin them to beneficially reduce the branch weight load and allow your fruits to grow larger. Peaches (Prunus persica) and nectarines (Prunus persica var. nucipersica) should be thinned to one fruit every 5 to 7 inches (12 to 17 cm). Plums can be a little closer at 4 to 6 inches (10 to 15 cm) apart. Apples should be thinned to one fruit per cluster, and one cluster every 5 to 7 inches (12 to 17 cm).

It is important to note that fallen, uneaten fruits can create habitat nuisances, so it is best to remove and discard them. They can be slipping hazards or attract undesirable pests and diseases. Often, they will bring in wildlife, which can either be a positive or negative attribute depending on your goals. For example, sweet cherries (Prunus avium) attract fruit flies, birds, raccoons, opossums, foxes, and bears. Their roots are like candy for gophers. Being able to eat cherries from your tree is a luxury that requires effort and inputs like nets, sprays, or plastic clam shells to exclude our wild fruitarian friends.

When selecting a cultivar of fruit to add to your landscape, keep in mind the time of year it will ripen and how you intend to use that fruit. Some cultivars of fruits are delicious fresh from the tree. Others are better when processed into dried, jellied, candied, or baked products. If you are adding a fruit tree to a school garden, make sure the fruit will ripen when school is in session. Peaches and plums may be delicious fruits that children like to eat, but if they ripen over the summer when no one is there to enjoy them, the tree is not optimally serving its purpose.

If you landscape with primarily natives, there are some very tasty North American fruits suitable for your space. Elderberries (Sambucus spp.), Saskatoon berries (Amelanchier alnifolia), blueberries (Vaccinium corymbosum), and gooseberries (Ribes spp.) all evolved in North America, and many cultivars are suitable for use in the landscape. Other North American tree fruits that are slightly out of our habitat range but can grow here include American plums (Prunus americana), pawpaw, and American persimmons (Diospyros virginiana). All these fruits can be quite delicious and add quite a bit of intrigue to your space. If native isn’t a requirement, but drought tolerance is, consider feijoa for its evergreen, year-round appeal, beautiful bark, edible flowers, and tasty fruits. This versatile plant from Uruguay can be trained as a tree, shrub, or even hedgerow.

Choosing and purchasing your fruit trees and shrubs

I highly recommend utilizing the summer to taste fruits and dial in what you are looking for to plant in the fall, when the rainy season starts. Local chapters of the California Rare Fruit Growers (CRFG) or the North American Fruit Explorers (NAFEX) often hold tastings that are open to the public. Your local farmer’s market can also be a great source of fruits that are less commercially available.

At my chapter of CRFG (Redwood Empire), we have an annual tree sale in Santa Rosa, California to raise scholarship funds for our local university students. These trees were grafted in March, grown by one of our members, and will be available to the public in August. We also have public tastings where I work at the Wolfskill Experimental Orchard in Winters, California throughout the summer for people to try a huge range of diversity of mulberries (Morus spp.), Stone Fruits (apricots, nectarines, peaches, plums – all in the Prunus), figs, pomegranates (Punica granatum), persimmons (Diosypros spp.), kiwi (Actinidia spp.), and grapes (Vitus vinifera).

Planting your fruit tree or shrub

When preparing to plant your fruit tree or shrub, it is important to prepare your root ball by trimming any roots that look like they are circling each other. If the plant is allowed to continue to have circling roots, it will eventually girdle the crown, strangling and killing the top of the plant. You can avoid circling roots by taking your shovel and fluffing the sides of the root ball. If you intend to keep the plant in a pot for an extended period, it can be beneficial to hack off the bottom quarter of the root ball when the plant is dormant and replenish the bottom of the pot with fresh soil.

As you plant your new fruiting tree or shrub, be mindful of the depth of the crown. The crown of the plant is the root-shoot interface at the soil line. For many kinds of fruit trees, you will want to maintain the existing root-shoot interface to avoid crown rot, a fungal disease that attacks the crown when it is planted too deeply. If you have gophers, you will want to protect your new plants by putting them in gopher wire baskets, especially if it is a fig or peach. The roots of those plants are like candy to gophers.

If you are planting it in a container such as a pot or wine barrel, select a well-draining potting mix, and add some of your favorite compost or slow-release fertilizer. You can top the container with a little mulch to prevent water loss from the top of the pot if you are mindful of the crown of your plant. If you are planting in the ground or a raised bed, using your native soil is best for the long-term anchorage of your plant. Dig your hole slightly larger than your root ball, fluff your roots, and place it in your hole. Backfill with your native soil. After planting in either the container or ground, be sure to water your new plant thoroughly. Remember that even plants listed as drought tolerant will require sufficient water in the first year or two for them to become established in your space.

Be prepared to care for your fruit plant

After your plant is in the ground, it may be necessary to stake it. Avoid tying the plant too tightly to the stake as this will eventually girdle your plant, cutting off its supply of water and nutrients, and ultimately killing your plant. It is better if you have 2 to 3 stakes surrounding your plant, each with its own loose tie. This will allow the plant to have a little flex. Some flexing is important to allow the stem to strengthen on its own. If it is planted too close to a structure that shades it, the plant will tend to reach for the light and grow crooked. In this case, training or pruning will be necessary for it to maintain a healthy and attractive shape.

Different plants will require various methods of training. For example, grapes and kiwi require a trellis system. Cane berries (Rubus spp.) can also be grown on a trellis. Apples and pears lend themselves well to an espalier trellis system, being grown along a flat plane. Prunus species prefer an open-vase shape similar to that of a well-pruned rose bush.

When pruning your fruits, you will need to know if the plant bears fruit on first- or second-year wood. This will influence your decisions on how to shape your tree. Remove crossing, broken, and diseased branches. This will open the canopy of your fruit, allowing more sunlight to penetrate through the plant. More sunlight decreases your chances of powdery mildew and will facilitate even ripening of your fruits. Pruning in the winter facilitates vigorous, rejuvenating spring growth. Pruning in the summer reduces the overall size of your tree. Keep in mind the direction that your buds are facing on the plant because that will be the direction the new growth forms when those buds break dormancy.

Although growing fruit can require a bit more thought and maintenance than many ornamental plants, incorporating delicious gems into your landscape can be a fun and rewarding endeavor. They can provide habitat and food for wildlife and add elements of focal interest to your space. Below you will find some links to explore some of my favorite resources to peruse for growing fruits. Lastly, I want you to not be afraid to try again if you don’t succeed the first time. Dialing in the right fruit for you can be tricky, but it is well worth the effort when you get to share the fruits of your labor with family and friends. Happy growing!

This article was sponsored by: Pacific Nurseries