How to Grow Fruit and Berries in Containers
While growing flowers and vegetables in containers can be a snap, growing fruit trees and berries takes a little more forethought. You need to become familiar with such things as rootstocks, pollination, and climate adaptation. You may need to prune and thin.
Many types of fruits and berries adapt nicely to growing in containers. And plant breeders continue to develop compact varieties especially suited to container growing. Growing fruit in containers has advantages, as well. Most noteworthy is the mobility that containers provide. If frost threatens, you can move your fruit trees under cover for protection. So although container fruit growing takes a little more effort than growing flowers or vegetables, the payoffs are well worth it.
You probably remember from Biology 101 all about how pollen moves from the male part of the flower to the female part, fertilizing it, and causing a fruit to grow. Some fruit trees, like peaches, have compatible male and female flower parts on the same plant — this kind of plant is called self-fruitful. You can grow one peach tree — or other self-fruitful plant — by itself, and it will produce fruit.
Other fruits, including some apples and blueberries, produce more and better quality fruit if they’re cross-pollinated, which means that they receive pollen from another variety. You can grow one apple or one blueberry plant and probably get some fruit, but you’ll get much better production if you have a second, different variety growing nearby. For example, if you plant one or two Bluecrop blueberries, you’ll get some fruit, but if you plant one each of Bluecrop and Earliblue varieties of blueberry, you’ll get a bigger, better harvest.
For some fruits, such as plums, you need a specific variety (usually one that blooms at the same time) for proper cross-pollination. Pollinators carry pollen from flower to flower, or even from one part of a flower to another part. Pollinators are usually bees, flies, or other insects, and you probably have plenty of those in your garden. Even city dwellers will have bees and flies buzzing around, especially if they plant flowers nearby.
Most fruit trees have two parts: the rootstock and the scion. The rootstock is the below-ground portion of the plant. The scion is the above-ground, fruiting part of the plant. The point at which a scion joins the rootstock is called the graft union or bud union. The graft union is usually indicated by a swollen or curved part of the trunk a few inches above the soil level. Below the graft union is the rootstock; above is the scion.
In simple terms, when nurseries grow fruit trees, they bud or graft the scion variety onto the rootstock to take advantage of the best attributes of each plant.
Obviously, the scion produces great tasting fruit — that’s a considerable attribute. But a good rootstock can contribute qualities like adaptation to specific soil types, hardiness, or size control. If grown on their own roots, most fruit trees get huge — way too big to grow in containers. But if grown on rootstocks that keep them smaller, called dwarfing rootstocks, these same fruit trees become ideal for containers. Apples perfectly demonstrate the value of dwarfing rootstocks. A normal apple tree can grow up to 40 feet high. But the same variety grown on a dwarfing apple rootstock can be reduced in size by over 75 percent, reaching just 10 feet tall.
Not every type of fruit is available as a dwarfing rootstock. But, the genetic dwarf fruit tree is naturally smaller. For example, a standard (normal size) peach tree may reach 25 feet high. A genetic dwarf peach rarely gets over 6 feet high — perfect for containers. The number of genetic dwarf fruit tree varieties available is growing. Unfortunately, their fruit isn’t always as good as that of standard varieties, but it’s certainly better than store-bought fruit!
If you have a favorite variety of fruit, look for it on a dwarfing rootstock first. If you can’t find one, check to see whether it’s available as a genetic dwarf.
Semi-dwarfing rootstocks dwarf the trees about 25 to 50 percent. Depending upon the type of fruit tree and variety, these may also be good choices for large containers.

Gardening Glossary
annuals
Plants that complete their entire life cycle within one growing season. The plant germinates from seed, grows and blooms, and then produces seed and dies.

Gardening Glossary
biennials
A plant that take two growing seasons to complete its life cycle. It germinates and grows leaves and stems in the first year; produces flowers and fruit (seed) in the second, and then dies.

Gardening Glossary
bolt
When a plant flowers or produces seed prematurely.

Gardening Glossary
cold frame
A wooden or concrete block box in which you can grow plants or hold dormant during the cold winter months.

Gardening Glossary
cole crops
A family of vegetables, including broccoli, cabbage, cauliflower, kale, and Brussels sprouts. They thrive in cooler weather.

Gardening Glossary
complete fertilizer
Any fertilizer that contains all three of the primary nutrients, N-P-K (nitrogen, phosphorus, potassium). Phrase is based on regulations governing the fertilizer industry. Does not mean that the fertilizer literally contains everything a plant needs to thrive.

Gardening Glossary
deadheading
The practice of pinching or cutting off spent flowers

Gardening Glossary
evaporative-pad humidifier
A humidifier in which fans blow across a moisture-laden pad that sits in a reservoir of water.

Gardening Glossary
harden off
The process of acclimating plants grown indoors gradually to the brighter light and cooler temperatures of the outside world.

Gardening Glossary
hardiness
The ability of a plant to survive is called its hardiness.

Gardening Glossary
humus
A stable end product of organic-matter decomposition that's believed to increase microbial activity in soil, improve soil structure, and enhance the root development of plants.

Gardening Glossary
Bacillus thuringiensis Bt
An effective bacteria that attacks only the larvae of caterpillar family insects. It is safe to other insects, animals, and humans.

Gardening Glossary
macronutrients
Mineral nutrients that plants need in the largest quantities: nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.

Gardening Glossary
mulch
Organic or inorganic material placed over the surface of soil, usually directly over the root zone of growing plants. Used to conserve moisture, kill weed seedlings, modify soil temperature, provide attractive covering to garden beds.

Gardening Glossary
organic matter
Once-living stuff like compost, sawdust, animal manure, ground bark, grass clippings, and leaf mold (composted tree leaves). Used to enrich soil and improve soil texture.

Gardening Glossary
perennials
Any plant with a life cycle of three or more years. Herbaceous (non-woody) perennials include flowering plants and herbs, mainly. Woody perennials include trees and shrubs. Longevity depends on the plant and growing conditions.

Gardening Glossary
pH
The measure of soil's acidity. Soil with low pH means it's too acidic; soil with high pH means it's alkaline. Most plants grow best in soil with a pH value between 6.5 and 7.2. Neutral soils measure 7.

Gardening Glossary
photosynthesis
The process through which plants take nutrients from the air and from the water in the soil to produce sugars that fuels the plant's growth.

Gardening Glossary
primary nutrients
Nitrogen, phosphorous, and potassium are the three nutrients plants need in the largest quantities.

Gardening Glossary
root crops
Plants with edible underground roots such as onions, carrots, beets, potatoes, turnips. Most root crops are cold-weather crops.

Gardening Glossary
self-blanching
A type of cauliflower with leaves that naturally curl over the head and exclude light. Requires cool temperatures for leaves to curl effectively.

Gardening Glossary
sets
Small onion bulbs, about 1/2-inch wide, that were started from seed the previous year. Grow onion sets with the pointy end up.

Gardening Glossary
side-dressing
The act of adding a small amount of fertilizer around or "on the side" of plants after they're growing.

Gardening Glossary
succession planting
Planting small, 2-to-4-foot patches of plants every two weeks throughout the growing season so that you can harvest a crop over an extended period of time.

Gardening Glossary
thinning
The act of cutting the least robust seedlings in your garden to give the healthier plants more room to grow.

Gardening Glossary
vining crops
Crops that grow on vines, such as cucumbers, melons, pumpkins, and winter squash. They usually require support (staking, trellising, etc.) to keep them off the ground.