Creating a garden bed directly next to a house, known as foundation planting, requires careful planning to protect the building’s structural integrity while ensuring plants can thrive. This unique environment next to a wall creates a specific microclimate that influences both plant health and the longevity of the home. Successfully installing this type of bed involves critical ground preparation followed by plant selection tailored to the conditions of the house environment.
Preparing the Foundation Area
Preparing the ground properly is the most important step for preventing future moisture damage to the home’s foundation. Begin by clearing the intended bed area of all existing vegetation, such as grass or weeds, to expose the native soil. Aim for a bed width of at least two feet to allow adequate space for root development and maintain a safe distance from the foundation wall.
The entire prepared area must be graded so the soil slopes distinctly away from the house structure. This sloping directs rainwater and snowmelt away from the foundation, preventing pooling and potential pressure buildup against basement walls. A standard guideline suggests a drop of at least six inches over the first ten horizontal feet, achieving a five percent slope for effective drainage.
Building the Structure: Edging and Soil Creation
Once the proper slope is established, install a physical border to contain the soil and mulch. Edging materials define the garden space and prevent the erosion of topsoil into the surrounding lawn or hardscaping. Common options include:
- Stone
- Brick
- Metal
- Wood
Commercial-grade metal edging is durable, while natural stone or brick provides a substantial barrier.
The existing soil next to a foundation is often compacted and poor in nutrients due to construction activities, making it unsuitable for most flowering plants. For optimal growth, the bed should be filled or amended with a high-quality growing medium. A mixture of fifty percent screened topsoil and fifty percent compost is recommended for creating a nutrient-rich, well-draining base.
This blend should include a high percentage of organic matter, such as composted manure or shredded leaves, as it improves soil structure and water retention. This rich medium encourages healthy root growth within the bed. When filling, ensure the finished soil level maintains the established slope away from the house to preserve drainage.
Choosing Plants for the House Environment
Selecting the right plants for a foundation bed requires understanding the unique microclimates created by the house walls.
Microclimate Considerations
A south-facing wall absorbs sunlight all day and radiates heat back out, creating a significantly warmer environment. This requires species that tolerate high heat and reflected light. Conversely, a north-facing wall remains in deep shade, requiring plants that thrive in cooler, lower light conditions.
Roof overhangs also influence the microclimate by preventing natural rainfall from reaching the soil directly beneath them, creating a very dry zone. Plants chosen for these areas must be drought-tolerant or require supplemental watering.
Size and Root Management
Plant size selection is important to prevent damage to the house structure and maintain proper airflow. Choose species whose mature height and width will not touch the siding or impede access to windows.
Avoid planting large shrubs or trees with invasive root systems too close to the building, as roots can damage foundations or plumbing. A general rule is to select plants that mature to a height of no more than two-thirds the height of the adjacent wall for a visually balanced look.
Long-Term Care and Maintenance
Ongoing care focuses on maintaining conditions that protect the home while supporting plant health. Mulching is important for moisture retention and weed suppression, but it must be applied carefully.
A layer of mulch two to four inches deep is sufficient to retain soil moisture and regulate temperature. Because organic wood mulch can harbor pests, leave a gap of six to twelve inches of exposed soil between the mulch line and the house siding or foundation.
Since the foundation bed is often shielded from rain by the roofline, monitoring soil moisture is necessary. Apply supplemental watering directly to the root zone of the plants. Routinely prune all plant material to keep it clear of the house siding, promoting air circulation and preventing moisture buildup that could lead to rot or mold.