Gardening: What makes a good container garden

Container gardening has grown in popularity in recent years for a lot of reasons.

Gardeners with limited space and time to garden find them an easy solution to both challenges. Those of us who no longer can crawl around on the ground weeding and planting find their height much easier to manage. Containers dress up outdoor patios and entertaining spaces. Finally, with recent developments in dwarf fruit and vegetable varieties, they can easily grow food among the flowers.

What makes a good container garden? First is the type of container you choose. Larger is usually better because roots will have room to grow, and the soil will hold more water to keep the plants well-hydrated on a hot summer day.

Ideal containers need to be 16 to 24 inches in diameter and be made of wood, plastic, fiberglass, stone or hard-fired clay. Metal and terra cotta pots are not recommended because the metal will absorb too much heat in full sun which kills roots while terra cotta will crack during the winter if not stored indoors. Containers should have a drain hole to allow excess water to drain away. If they don’t, plant into a second pot with holes and place blocks to support the liner pot inside the outer pot to allow for drainage.

Always use a good-quality potting soil. Commercially prepared potting mixes contain a high percentage of peat moss or coir fiber that holds water well and is light enough to support strong root growth. Garden soil tends to pack down and be hard to water again if it dries out. It is also heavier than potting mix, which makes moving containers harder.

Don’t fill containers half full of packing peanuts, rocks and even pine cones to save on the amount of soil in the pots. This disrupts the movement of water through the container because it pools at the bottom soil surface and can’t drain properly.

Watering containers can be a challenge when it gets hot. Larger containers may only need to be watered once a day while smaller ones might need it twice a day.

There are many simple and inexpensive irrigation systems on the market that can abate this watering challenge. They often consist of microspray heads set in each pot and tied into an electronic timer hooked either to a hose bibb or time box and set to come on at specific times. With such a timer, you can run away on vacation and not worry about your plant babies.

Perennial plants can be planted in containers and left outdoors in the winter with a few cautionary recommendations. Because containers are open on all sides, the plants are more exposed to fluctuating cold temperatures. While we are in USDA zones 5 to 6, perennials in pots should be hardy to Zone 4 or moved to a protected spot during the winter.

Stay tuned for next week’s article. I will feature a local container gardener’s tips for gardening in pots.