Growing plants in containers is one of my favorite ways to garden. Come August, however, I’ve had it with deadheading and lugging watering cans. Last spring, when I was preparing to pot up my containers, the memory of spent, sticky nicotiana blossoms clinging to my fingertips came rushing back, and I wondered—is all this fuss and fluff worth it? Do containers really need that much care, or is it just a lot of hype? That’s when I decided to embark on an experiment. I planted several sets of identical containers and gave one pot in each set only water and the other the royal treatment: fertilizer, primping, and pruning.
By midsummer, it was clear that containers need more than just water. The water-only containers looked pathetic: The plants were puny, had few flowers, and their leaves were often an unhealthy yellow. The containers given more TLC thrived with abundant growth and flowers. The moral of the story is that a regular-maintenance checklist is the best way to get great-looking containers from beginning to end. Now that I know that all of the work really does pay off, it makes the rewards that much sweeter.
1. Provide a steady supply of water and nutrients
The warm temperatures of summer send plants into a growing frenzy. If they don’t have access to adequate water and nutrients, they will be stunted and sickly. Watering can be a bit of a balancing act: too much or too little and your plantings will suffer. My strategy is to water containers thoroughly when the soil surface becomes dry to the touch. During the hottest part of the summer, this can mean watering at least every day. I add water to each pot until I see it draining from the bottom, which ensures that moisture has reached the deepest roots. I also avoid watering at the end of the day. Without sunlight and warmth to evaporate moisture on leaves, the foliage stays wet longer, making it more susceptible to foliar diseases.
Most gardeners fill their pots with soilless mixes, which lack organic matter and nutrients. To provide plants with the food they need, I give my containers a regular dose of fertilizer. I add a balanced, granular, synthetic or organic, time-released fertilizer to the potting mix at planting time. This will slowly feed the plants for the next few months. Because container plants are heavy feeders, I also begin feeding the pots with water-soluble fertilizer, which roots can take up instantly, about a month after planting. I mix the liquid fertilizer at half strength—because the soil already contains granular fertilizer—and apply it at watering time every two to three weeks until the end of the season.
You get what you give
Snip off spent flowers and unsightly foliage
I give my containers a good primping every week or so. Deadheading faded blossoms and removing damaged or diseased leaves and stems not only keeps plants looking good but also keeps them productive and healthy. Deadheading redirects a plant’s energy from seed production back into flower production. When snipping off blooms, cut flower stems back to a leaf node or main stem. Do not leave any unsightly headless or leafless stems.
Removing problem leaves back to the main stem is also important. If an entire stem is damaged or diseased, cut it back to the nearest healthy growing point or all the way back to the base. It’s best to remove disfigured leaves and stems as soon as you notice them. Injuries attract insects and encourage diseases. Many container plants like pelargoniums, also known as annual geraniums (Pelargonium spp. and cvs.), have a tendency to develop a fungal disease called botrytis on their lower leaves. Don’t be shy about digging deep into plantings to look for problems. Likewise, take a peek under your trailing plants, and remove any brown or tattered foliage.