As an orchardist working in a crowded city, one of the most common questions I get is if people can grow fruit trees and perennials in containers. For some, there are concerns about the soil quality in their neighborhood given the impacts of heavy development, heavy metals, and other contaminants that might have altered the soil fertility through time. For others, their ability to plant directly into the soil is controlled by their landlords, community garden rules, water access, or even living entirely surrounded by concrete. In any case, this guide can help you think about the aspects of taking care of plants in containers that you should consider before getting started. 

WHY PERENNIALS?

Perennials are plants that stay alive for multiple seasons and come back year after year. They encompass trees, shrubs, vines, some herbs, and some flowers; all with varying life spans. Focusing on growing these types of plants helps us to develop unique relationships season after season. Often these plants have woody, more hardy structures and, therefore, are more structurally sound than annual vegetables when growing in a container. This can make them slightly more pest resistant as well which is helpful in a city full of critters like squirrels and raccoons. Additionally, perennial plants store their energy in their roots, which often makes them easier to propagate and share with the community.

CONSIDERATIONS BEFORE YOU START

The last thing you want is to rush forward and bring plants home to an uninhabitable place to live. Like with any garden or orchard design the most important things to consider are space, light, and water access. Keep a notebook or journal to track your journey! 

Start with assessing your space. Check the container size portion of this blog and do your own research before acquiring plants. I recommend starting slow with a couple plants at a time.

Shade over an container garden (POP staff)

SUN & WATER 

Take time to watch how the light falls in your space, this is vital to make sure you understand how much light your plants will receive. Try to place the plants where they will receive adequate sun for their needs. South facing gardens receive the most amount of sunlight and north facing gardens receive the least. East facing gardens will receive morning light and west facing will receive afternoon sun. Using a compass or map, check which direction your garden faces. Many smart phones have the ability to download a free compass app as well. Plants sun and shade conditions can be categorized in the following ways: 

• Full sun-  plants require 6+ hours of sunlight a day 
• Partial sun – plants require 4 to 6 hours of sunlight a day
• Partial shade-  plants require 2 to 4 hours of sunlight a day 
• Shade – plants require less than 2 hours of sunlight a day

The light requirements of your plant will vary so be sure to review this as you access the light available in your space. Regardless of your plant choice it will need access to water regularly. Think critically about how often you’d realistically be able to water and how accessible water access is to your garden. In the peak of summer in Philly (June – August) plants will need water at least once a day in the evening or early morning. Plants in containers larger than 12’’ should be soaked thoroughly through the base. In the spring and fall months you may be able to go down to 2-3 days a week depending on precipitation. In the winter you can stop watering altogether. Many row home or apartment complexes don’t come with a hose, so consider acquiring a watering can or alternative vessel to get to a deck or porch. 

CONTAINER SIZE

Since we know perennials develop dense root structure over the years, there will eventually be a limit in how comfortable it can be before it outgrows its space. That’s why it’s important to select a pot that will give it comfortable growing space for several years at a time. Every pot you select should have holes in the bottom for drainage

Fruiting strawberry in container (POP staff)

One of the best things about container gardening is that you can pick from a wide variety of sizes and often use recycled plastic for your growing efforts. I recommend checking out places like Rabbit Recycling that allow people to take used materials for free!

You should pot up no more than ⅓ larger than the size of the container the plant comes in from a nursery or plant sale. This will allow the plant to settle into its new home slowly and support you in not over watering it. Below is a chart with examples of minimum sizes. This will depend on the variety you select!

PLANT SELECTION

Perennial herb selection from our Potted Perennial workshop this summer where participants got to pot up and take home plants. (POP staff)

In Philadelphia we are currently situated in a zone 7b climate – although this continues to change. When making a plant selection make sure you are purchasing plants that can grow in this area. Many times when doing research on the internet, you will find a wide range of possibilities, some with ambitious recommendations saying you can “grow anything” if you try hard enough. Save yourself the heart break and lean toward native or acclimated plants to secure your success. While it’s not impossible to grow some plants outside our climate zone like tropical plants or indoor plants, note that they may require more intense equipment and indoor set ups for winter months. There are many great plant sales that happen in Philly each spring that carry a wide variety of plants that are acclimated to this climate!  Some of POP’s favorite sources for fruiting plants are listed here. 

Remember that when potting in containers, you are in full control of supporting the plant by providing its water, nutrients and making sure it’s getting adequate light. It is less likely to self regulate these things when placed outside of its natural habitat. You will need to water and fertilize potted plants more frequently than those growing in the ground.  Perennials tend to require less water than annual plants in containers, although this will vary depending on the plant type, container size, and placement.

During the winter months this is especially important as potted plants don’t have the warmth of the soil and are more vulnerable to cold. Unless you’re planning to move them indoors, you might presume 5b for a safe climate zone choice for outdoor potted plants.  A simple way to help ensure your plant makes it through the winter months is to either cover it with leaves, like we do our figs, or simply bring it closer to the house which creates a small micro climate. You can read more about this here on our blog!  

After about 2 years or if you see roots at the bottom of your pot, it’s time to pot up your plant to the next size container and add more fresh soil.  For potted plants that can’t be moved up another size, root pruning can help; remove them from their pot while dormant in fall or winter, prune the roots and the top growth equally, and repot in the same container with new soil. 

SOIL

It is important to use a mix that is well adapted to drought and made for container/raised bed gardening. You can also create your own soil mix including compost, perlite, organic soil mixes and or vermiculite. Be cautious of using too much peat since it is a finite material! It’s important to know if your plant requires soil amendments before you plant. For example blueberries require soil acidifiers to support their growth and fruit production. There is free compost available to Philadelphians at the Organic recycling center. 

Photo from our last Potted Perennials workshop at Open Kitchen Sculpture Garden

We recently hosted two Potted Perennial workshops at Open Kitchen Sculpture garden and Batram’s Garden and hope to continue to welcome more conversations on growing edible fruits in containers. Stay tuned for future workshops where we can plant together and share about our experiences growing in alternative spaces!

This edition of the POP TIPS was prepared by Carolina Torres with the support of Phil Forsyth and Corrie Spellman-Lopez.  

SOURCES

https://extension.umd.edu/resource/soil-fill-raised-beds

https://ag.umass.edu/home-lawn-garden/fact-sheets/container-gardening-with-fruit

https://www.southernliving.com/best-fruits-for-containers-8623509

https://extension.psu.edu/planting-in-sun-or-shade

DISCLAIMER

The Philadelphia Orchard Project stresses that you should not consume parts of any wild edible plants, herbs, weeds, trees,​ or bushes until you have verified with your health professional that they are safe for you. As with any new foods that you wish to try, it is best to introduce them slowly into your diet in small amounts.

The information presented on this website is for informational, reference, and educational purposes only and should not be interpreted as a substitute for diagnosis and treatment by a health care professional. Always consult a health care professional or medical doctor when suffering from any health ailment, disease, illness, or injury, or before attempting any traditional or folk remedies. Keep all plants away from children. As with any natural product, they can be toxic if misused.

To the best of our knowledge,​ the information contained herein is accurate and we have endeavored to provide sources for any borrowed​ material. Any testimonials on this web site are based on individual results and do not constitute a warranty of safety or guarantee that you will achieve the same results.

Neither the Philadelphia Orchard Project nor its employees, volunteers, or website contributors may be held liable or responsible for any allergy, illness,​ or injurious effect that any person or animal may suffer as a result of reliance on the information contained on this website nor as a result of the ingestion or use of any of the plants mentioned ​herein.