The following excerpt is from Allyson Levy and Scott Serrano’s new book Cold-Hardy Fruits and Nuts: 50 Easy-to-Grow Plants for the Organic Home Garden or Landscape (Chelsea Green Publishing, March 2022) and is reprinted with permission from the publisher.
Every site is unique, whether it’s a backyard, front yard, raised bed, community space, rooftop garden, farm plot or container garden on a deck, and there is no substitute for knowing your site. Sometimes you can do lots of research on the growing requirements of a particular fruiting plant and still have it die after lavishing lots of attention on it. If there is one piece of advice we can give, it is this: Gardening takes patience and requires close observance of your landscape over time. But sometimes it is not feasible to be patient, especially when you want to immediately get plants in the ground. We often say that you must kill a plant several times to learn how to grow it correctly. Our goal is to expose you to low-maintenance, pest-resistant plants that should require little care after you provide enough water for them for one growing season. We have listed a few things to keep in mind before planting and some suggestions for caring for your plants during the growing season.
Choosing a Planting Site
When selecting the best planting site for your plants, there are a number of items to consider.
Determine the Soil Content at Your Planting Site: Does the soil at your location contain a heavy amount of clay, sand or stone, or is it loamy? Depending on how large a planting area you have, there could be many different types of soil on your property. Taking soil samples from several of the places where you want to plant can help determine this. Many good sources of information on soil types can be found in university agricultural programs.
The pH (Acidity) Level in Your Soil: Another factor to take into consideration is the pH (acidity or alkalinity) of your soil. Most plants can live in the slightly acidic range from 6.5 to 5.5 pH. But certain plants require nutrients that can only be absorbed into the root system based on specific pH levels in the soil. Soil testing is one of the best ways to determine what type of soil you have. You can do this by contacting your local university agricultural extension service or the agricultural testing labs in your area. These organizations can sometimes provide soil testing services, in addition to selling simple soil testing kits with instructions that allow you to test your own soil, and advise what to do if you need to change the acidity levels of your planting site.
Soil Depth in the Planting Area: It is also a good idea to understand how much topsoil you have to work with. Some planting areas have deep soil with a depth of 5 feet (1.5 m) or more for digging before you hit bedrock. Other areas might have shallow soil with only 1 foot (31 cm) to work with. Sometimes digging test holes in several places may help you determine the depth of your soil in order to understand the best place to plant trees on your property. If you have lots of choices about where to plant, choose a site with deep soil, though most plants are adaptable and will tend to have horizontal root structures if they are planted in shallow soil areas. If you have soil that is only a few feet deep, it may benefit your trees to plant them in large spreading mounds. These can be 6- to 10-foot (1.8–3 m) wide circles that gently rise to a 1-foot-tall slope. A plant is buried in the center of the mound so that its roots will have more room to spread out. The only drawback to this planting method is that every few years, you will need to add soil to the width of the mound to give the roots more room as they grow outward.
Determine Your Light Exposure: The amount of light that shines directly on a planting area determines the light conditions, which can range from full sun to full shade. This is referred to as a planting aspect, and it will help you determine what type of plant will thrive in a particular site. For the best results locate a planting area that has a large amount of south-facing sun exposure, which is easy to locate with a compass. Below is a general guideline for evaluating the different aspects of sunlight exposure to determine what plants will grow well in a particular planting area. If you only get three hours of sunlight, but it is in the hottest part of the day (noon until 3 p.m.), that may be better sun exposure than four hours of sun in the cooler part of the morning. Also keep in mind that the intensity and amount of light exposure changes at different times of the year.
Here are some general guidelines for sun exposure:
Full Sun: 12 to 8 hours of direct sunlight.
Part Shade: 6 to 4 hours of direct sunlight when the sun is hottest (midday to afternoon).
Part Sun: 4 to 2 hours of direct sunlight, generally in the early morning or late day.
Full Shade: No direct sunlight; filtered sunlight to complete shade.
Determine Your Hardiness Zone: Most plants are rated by their hardiness factor, which is defined as the ability of a plant to survive the coldest temperatures of the winter. In addition to the cold, it measures a plant’s ability to tolerate heat, drought, flooding and wind. A hardiness zone is a geographic area defined to encompass a certain range of climatic conditions relevant to plant growth and survival. The USDA Plant Hardiness Zone Map is the standard by which gardeners and growers can determine which plants are most likely to thrive at a location. The map is based on the average annual minimum winter temperature, divided into 10 degrees Fahrenheit (5 degrees Celsius) zones, which was last updated in 2012.
Microclimate: The microclimates in your planting area can also play an important role in a plant’s ability to survive. A microclimate is a local set of atmospheric conditions that differ from those in the surrounding areas. This can be as little as a few degrees, but may be substantial enough to allow a less hardy plant to grow in an area where it normally would not survive. If you live in an urban area, hard surfaces like asphalt and concrete absorb the sun’s energy and can make a planting environment even hotter. South-facing areas are exposed to more direct sunlight and can be warmer for longer periods of time. Also keep in mind that cold air tends to sit in the lowest parts of a planting site, and those areas can stay colder for longer periods of time. They may be more difficult to grow a plant than a warmer site only 30 feet (9.1 m) uphill from that location.
Determine Your Water Source: A tree or bush planted the first year will generally need 1 inch 2.5 cm) of water a week to stay healthy. So another important factor that goes into considering where to plant must also be convenient access to water.
Buying a Plant
What you grow can depend on where you are able to purchase it. Your local nursery may have a good selection of different large-sized containers of blueberry varieties, for example, to choose from. But if you are looking for a “seedless female” che, it is most likely that it will only be available as a small-sized plant from a specialty mail-order nursery. There are several options for buying plants, and here are the most common.
Bare-Root Plants: A wide selection of bare-root plants is available through mail-order nurseries in early spring or late fall while the weather is still cool. These plants are dormant and shipped without any soil around their roots. Dormant plants are commonly wrapped with damp shredded paper and enclosed in a plastic bag to keep them moist during the time they are in passage. The advantage of this is being able to see all of the plant’s root system. When you place a bare-root shrub or tree in soil, you can arrange the plant’s roots so that they will grow into the soil in a symmetrical manner. The disadvantages of buying bare-root plants is that they are generally smaller than what you can buy at a local nursery. Because they have exposed roots, they are more fragile and need to be planted fairly quickly after you receive them. They can easily dry out and must be protected from direct sunlight. Also, the window for shipping bare-root plants is much shorter than for potted plants because it must be done when the weather is cool.
Potted Plants: Plastic containers are the standard way nurseries sell plants to the general public. The advantages of potted plants are that they are available for sale for most of the year (excluding winter) and their root system tends to be more substantial and less likely to be shocked when planting. The downside to a containerized plant is that you cannot see the entire root system, so you may get a plant that is damaged, or one that is pot-bound. Also, nurseries tend to stock the familiar, tried-and-true potted plants, so the choices can be limited.
Balled and Burlapped Plants (B & B): These are plants dug up from the ground by a tractor and wrapped. Balled is in reference to the shape of the root ball with the soil surrounding it. Burlapped refers to the wrapping material that surrounds the root ball and holds the loose soil and roots together. These types of plants are generally more expensive and have larger root systems that will not fit into plastic containers.
Some people are willing to pay the high prices for these extra-large plants because they want to get an instant big tree on their planting site. We believe that there are not enough advantages to buying B & B plants, and generally advise against them. Larger specimens often weigh hundreds of pounds, which is another disadvantage, and have a wire metal basket around the root system to contain all the loose soil, and many landscapers do not remove the burlap or metal cages from the plants after putting them in the ground. This bad, old-fashioned gardening practice can seriously damage a plant’s growing root system; we have seen old plant roots girdled and strangled by these types of metal cages.
Plants maintain a growth ratio between the roots and the growth aboveground, so the more intact a plant’s root system is, the quicker it will put vigorous energy into the growth above the ground. Although it is tempting to start with a big plant, a study by the Cornell University Agricultural Extension shows that common B & B plants have over 90 percent of their roots cut off when they are mechanically dug up. In another study by Cornell, two sets of the same species of trees were planted in one location. One set were moderate-sized nursery trees with intact root systems and the second set of trees were large B & B trees that had lost 90 percent of their roots. Over each growing season the smaller trees with intact root systems grew larger, while the B & B trees with reduced root balls only grew a few inches each year. After 13 years both sets of trees were about the same size!
What to Look For When Buying a Plant
Selecting a fruiting plant that has been properly grown and shaped by a nursery is the first step towards planting a tree or a bush that will thrive and be productive for many years.
The Structure of the Tree: Commercial growers that supply plants for nurseries often cut off the lower limbs of fruiting trees to raise the crown and create a taller tree structure, because most nursery customers that purchase a taller tree think they are getting a better deal. Under these circumstances the grower has shaped a tree for tallness but not for easy fruit picking. Picking fruit at a height of 4 to 7 feet (1.2–2.1 m) is more convenient than climbing on a ladder to get fruit that is 6 to 12 feet (1.8–3.7 m) high. So purchasing a smaller tree that can be pruned into the tree you ultimately want may be better than getting one already pre-shaped for height.
There is one positive advantage to having a tree with a higher canopy: Higher branches are less likely to be chewed upon by deer. This may be a good strategy if you have heavy deer activity in your planting area with no protective fencing.
Disease-Resistant Varieties: A plant’s disease resistance is its genetic ability to prevent a disease-causing pathogen from harming it. Some species develop resistance to diseases through deliberate plant breeding, or through the process of natural selection. In addition to good fruit productivity, many modern varieties have also been bred to resist the effects of different types of pathogens. When choosing plants, look for varieties and cultivars that have been bred to have the most resistance for diseases known to be prevalent in your geographic area.
Feature photo depicts che fruit on a branch. Photo courtesy of Chelsea Green Publishing.