Gardening in Containers and Raised Planters
We have always enjoyed potted plants on the deck or terrace at home. They soften the edges of hardscape, mute street noise, and gentle the space by creating a lush, colorful backdrop. Last year, I grew a few tomatoes in pots on our deck. The tomatoes did so well that I decided to grow more this year. After the deer devoured my potted sweet potatoes on the driveway—5 feet from the door—I have moved all containers but the smelliest mints and stinky rosemarys up to the protected reaches of my high back deck. Though, a very nosy groundhog brazenly walked 20 feet onto the deck to demolish a particularly tasty lance-leaved kale, so no garden is completely safe.
Once the idea was planted, it seemed only logical to have my favorite goodies growing only steps from the kitchen door. This year, there are several vining cherry tomatoes weaving their way through the balusters, narrow containers of Swiss chard, kale, beets and hanging baskets of hot peppers. The rapidly re-growing sweet potatoes are sprawling out over the deck at the dog run. Near ground level, this fenced area is patrolled by our ever-alert shepherds, Carly and George.
One of the beauties of container gardening is that plants are portable and may be moved around to find the ‘best’ spot for their culture. The Swiss chard wilted daily in the full sun, but has become lush when dragged into light afternoon shade. Another asset is that pots can be easily kept weed-free. Sure, the birds toss seed willy-nilly and there are a few stray sprouts, but nothing difficult. No yellow nut-sedge! Well-draining pots also reduce soil-borne diseases like Phytophthora. Container planting also allows areas such as an asphalt parking pad to appear soft and green. But the biggest advantage for us aging boomers is that plants in pots or raised beds are elevated for easier access. Harvesting potted herbs beats kneeling any day. And…my rosemarys survived the winter by the window inside the kitchen. It is easier to save tender plants when the whole pot comes into the house during winter months.
Kits for raised beds, living walls, towers and trellises are available from many sources to assemble at home, or you may build your own. Fabricate troughs or raised planters with cedar, treated wood or synthetic lumber for longer-lasting creations. Some folks avoid treated lumber around food crops. My garden's raised beds are made of synthetic timbers extruded from recycled plastic garden pots. Masonry walls are best for permanence, but expensive to install. Sometimes, permanence can be boring for a gardener. If a form will last one season, hold soil and drain, it can be used to grow a plant. The only limit is your imagination.
Container size and root volume is important. Lettuce needs little depth, but moisture is essential. Herbs may grow in little soil but prefer drier conditions. Crops like tomatoes or peppers need a much larger diameter pot and even moisture. For tomatoes, Julie suggests pots at least 14 or 16 inches across and larger, if possible. My tomatoes are in a variety of containers, from whiskey barrels to elegant Vietnamese hand-thrown pots. While a standard tomato cage will fit down inside larger pots easily, I have found a kit with sturdy uprights and snap together cross-pieces. Since my tomatoes have a rail to sprawl along, this form allows me to support them only on the open side. With lateral sprawl space, I can use indeterminate varieties, ones that keep extending throughout the season, but Julie uses determinate patio types that remain bushy and work well in tight places.
Creative trellising also is a good direction for the visual or craft-oriented person. From purchased purpose-designed frames to old box springs, broken ladders, antique wrought iron gates, heavy commercial cattle panels or homemade stands of galvanized pipe and sisal twine, if it will last a season and bear the weight of the produce—try it! One of my favorite images is of a small courtyard garden in a hutong in Old Beijing…a row of neatly hand-woven slings of twine supporting every pumpkin draping down from a massive overhead pipe trellis.
The Essentials: Food and Water
Managing containers requires a close watch on both food and water. Because there is little nutrient value in potting soil, and what is there gets washed away with frequent watering, it is important to add fertilizer often, every 10 to 14 days. Leafy vegetables thrive on nitrogen. When growing vegetables or fruit (yes, tomatoes are a fruit), more care is needed as too much nitrogen causes more leaf growth and no flowers. Choose an appropriate nutrient source for your crop. Vegetables benefit from fertilizers with trace elements or micronutrients already added. Slow-release formulas are perfect for this situation as they release a small amount of food with each watering. I keep six or eight different types of fertilizer at my potting bench and each formula is different.
Getting the hang of correct watering is a bit harder as some judgment is required. Stick a finger into the soil and see if it is cool and damp or hard and dry. Train your eye to spot water stress early, before damage is done. Look for slight graying, drooping tips or browning leaf edges. Use your hand to lift pots. Light pots need water. Smaller containers in a sunny location may need to be watered every day. If a pot dries out completely, it may be hard to re-wet. If water slips around the soil ball and runs directly out the bottom quickly, more attention is required to rehydrate. Truly dried-out pots should be soaked in a bucket or wading pool. One key is to keep pots—especially hanging baskets—slightly moist at all times.
Tips for Creative Containers
• Start small. See if you like the arrangement before making a huge commitment.
• Explore creative containers repurposed from discarded everyday objects.
• A few large containers are easier than many small ones.
• Grow what you love to smell, taste and use in the kitchen.
• Buy the best varieties such as Sun Sugar cherry tomatoes.
• Try something new and fun such as rainbow chard or dragon gourds.
• Plan for succession planting as seasons may be short for leafy greens.
• Compare varieties for durability: My lance-leaf kale was attacked by critters and curly kale was left alone.
• Use overhead space for decorative vines such as moonflowers or luffas.
• Grow special treats for the grandkids or your spouse. Mine devour Sun Sugars!
Make a Simple Window Box Gift
Containers are fabulous for gardeners with small spaces or limited mobility. Julie’s friend moved into a retirement apartment and was sad to give up her garden. Ever resourceful, Julie made up a simple deck container using a standard window box from the hardware store, filled with a mix of purchased potting soil and garden loam, then planted it with spring greens, leaf lettuce and spinach. Dressed with slow-release fertilizer, it needed only sunshine and water. Julie wheeled the garden box in on a dolly and raised it up on a small terrace table—perfect for ease of harvest. After the spring greens fade with the heat (six or eight weeks), it is easy to replace them with herbs or summer annuals.