A hard-sided plastic kiddie pool is a highly effective, low-cost solution for urban or small-space gardening. This unconventional method transforms an inexpensive, readily available item into a broad, shallow container, making it a practical DIY project. The wide surface area provides ample space for numerous plants, simulating a small in-ground garden plot. This offers the benefits of container gardening, such as controlling the soil environment and preventing soil-borne diseases. The pool’s plastic material retains moisture well and creates a defined, accessible growing space.
Preparing the Kiddie Pool for Planting
Transforming a kiddie pool into a functional planter requires specific physical modifications, with drainage being the most important factor. Since the plastic material is non-porous, water cannot escape naturally, which quickly leads to waterlogged soil and root rot. To counteract this, a series of 1-inch diameter drainage holes should be drilled across the bottom of the pool, spaced approximately every 12 inches.
It is helpful to also drill smaller, half-inch diameter holes around the lower edge, about half an inch up from the base. These serve as secondary drainage points if the bottom holes become plugged with soil. The pool must be placed in its final, sunny location before filling it with soil, as the weight of the moistened soil will make it impossible to move. Choose a hard plastic pool over an inflatable one for durability, and avoid any pool treated with chemicals that might leach into the soil.
If the pool has existing cracks or you want to prevent soil from escaping the drainage holes, line the bottom with a permeable material like fiberglass window screening or porous landscape fabric. This layer allows water to pass through while keeping the soil contained. For optimal drainage function, the filled pool should be placed on a level surface, potentially slightly elevated with bricks or wood supports to ensure water can flow freely from the bottom holes.
Ideal Vegetable Choices for Shallow Containers
The limited depth of a standard kiddie pool (typically 6 to 10 inches) restricts plant selection to those with shallow root systems or compact growth habits. This setup is perfectly suited for continuous harvesting of leafy greens, which generally require only 4 to 6 inches of soil depth.
Suitable Plants for Shallow Containers
- Leafy Greens: Varieties like lettuce, spinach, kale, and arugula thrive and can be repeatedly harvested using the “cut-and-come-again” method.
- Root Crops: Radishes are an ideal fast-growing crop, often maturing in under a month, requiring only a few inches of depth for their small bulbs to form. Carrots and beets can also be successful if you choose specific short or round varieties, such as Parisian Market carrots or container-bred beets. Avoid large, deep-rooting vegetables like standard potatoes or sweet potatoes, which need 10 inches or more of depth.
- Fruiting Vegetables: Compact, bush varieties are excellent choices. Bush beans, which grow in a contained mound rather than sprawling on vines, are productive and fit well. For larger crops like tomatoes and peppers, select determinate or dwarf varieties, as their smaller stature and limited root systems are better suited to the container size.
- Herbs: The wide surface of a kiddie pool is excellent for growing a diverse herb garden, including basil, chives, parsley, and thyme, which are known for their shallow root zones.
Soil Management and Watering Strategy
The unique nature of a shallow, plastic container demands a specific approach to soil composition and water application. Standard dense garden soil should be avoided because it compacts easily and impedes necessary aeration and drainage. Instead, fill the pool with a light, well-draining potting mix or a raised bed blend, often consisting of ingredients like peat moss, compost, and perlite or vermiculite.
Container soils tend to deplete nutrients more quickly than in-ground gardens due to frequent watering and limited volume, requiring a regular feeding schedule. Incorporating a granular slow-release fertilizer into the mix before planting, and supplementing with a liquid fertilizer every few weeks, will help sustain plant growth. A light soil mix also helps mitigate the high heat absorption of the plastic, which can cause soil temperatures to rise rapidly, potentially stressing the roots.
Monitoring moisture levels is particularly important because the pool’s plastic sides prevent evaporative cooling. To check the moisture, stick your finger about 2 inches deep into the soil; if it feels dry, it is time to water. Watering should be thorough until water flows freely from the drainage holes, ensuring the entire root zone is saturated. Applying water slowly or using a drip system helps the soil fully absorb the moisture, preventing water from simply running over the surface.