Growing plants upside down, known as inverted gardening, is a highly effective method for home growers seeking to maximize space and yield. This technique involves suspending a container so the plant grows down through an opening in the base, using gravity to assist with growth and structure. Watching a tomato or pepper plant defy expectations by trailing toward the ground has captured the imagination of gardeners with small balconies, patios, or limited yard space. This method proves that cultivating a thriving garden is possible even in restricted areas.
The Science Behind Defying Gravity
The ability of a plant to successfully grow downward and then curve back toward the light is rooted in a biological process called gravitropism. This natural mechanism ensures that a plant’s shoots grow upward, away from the pull of gravity, and its roots grow downward. The plant achieves this directional growth through the redistribution of a growth hormone known as auxin.
When a stem is oriented downward, gravity causes auxin to accumulate on the lower side of the stem tissue. In shoot cells, a higher concentration of auxin promotes cell elongation, causing the cells on the underside of the stem to grow faster than the cells on the upper side. This differential growth rate forces the stem to bend upward, a phenomenon called negative gravitropism. Although the plant is inverted, this internal hormonal response means it will always try to grow against the downward force, resulting in the characteristic U-shape seen in inverted planters.
Best Plants for Inverted Containers
Selecting the correct plant variety is paramount to the success of an inverted garden, favoring species that naturally vine or have relatively lightweight produce.
Ideal Inverted Crops
- Tomatoes: These are the most recognized and successful candidates because their vining habit adapts well to being suspended. Smaller-fruited varieties, such as cherry and grape tomatoes, perform exceptionally well since their reduced weight is less likely to stress the stem or container.
- Peppers: Smaller-fruited types like jalapeños or cayenne thrive in this orientation and benefit from improved air circulation.
- Cucumbers and Squash: These natural vining plants flourish as they trail downward without the need for traditional trellising.
- Herbs: Many herbs, including basil, mint, and oregano, possess shallow root systems and a lightweight structure, making them ideal for planting either inverted or as companion plants in the top of the container.
Setting Up Your Upside-Down Planter
Creating a functional inverted planter requires choosing a sturdy container, such as a five-gallon bucket or a specialized fabric planter, that can support the weight of wet soil and a mature plant. The first step involves cutting a hole, approximately one to two inches in diameter, into the center of the container’s base. This opening must be large enough for the plant’s stem but small enough to prevent the soil from falling out immediately.
To secure the plant and retain the soil, a small piece of mesh or fabric is placed over the hole on the inside of the container, with a cross-cut made for the stem. The plant is then gently inserted through the opening from the inside, positioning the roots inside the container while the stem and foliage hang down. The container is subsequently filled with a high-quality, lightweight potting mix, which can be amended with water-retention materials like vermiculite or perlite to manage moisture.
Proper watering is a specific consideration for this setup, as gravity quickly pulls moisture through the container, increasing the risk of the soil drying out. Gardeners should water from the top of the container slowly and thoroughly until water begins to drip from the bottom opening. This frequent watering, often daily during peak summer heat, ensures that the roots, located at the top of the inverted container, receive adequate hydration.
Benefits of This Unique Growing Method
The inverted gardening method provides several practical advantages, making it an excellent choice for urban and small-space growers. By suspending the planter, the technique maximizes the use of vertical space, allowing for productive gardening on balconies, patios, or decks where ground space is limited.
A primary benefit is the reduction in common garden pests and diseases. Since the plant and its fruit are held off the ground, they are less susceptible to soil-borne pathogens like blight, which often splash up onto the lower leaves of ground-planted varieties. This elevated position also minimizes the chance of ground-level pests, such as slugs or cutworms, reaching the foliage. Vining plants grown upside down eliminate the need for caging or staking, as gravity directs the plant’s growth, simplifying maintenance and improving air circulation around the canopy.