As the weather warms up, it’s impossible for northern gardeners not to be excited for color, color and more color. That usually means planting annuals and containers with annual flowers. Over our 150 years of publishing gardening information, we’ve discovered some great tips for getting the most from your annuals and containers.
Purchase pansies fully loaded. In a recent issue of Northern Gardener, Michelle Mero Riedel recommended buying pansies in spring with lots of blooms and buds already on them. During a cold spring like this one, pansies won’t set new bloom unless temperatures are above 40 degrees. Pansies can take temperatures down to about 28 degrees, but if nights will be cold and you can bring them inside, do so.
Prune for maximum bloom. Whether pansies or petunias, annuals benefit from pinching and deadheading. Pinching forces plants to send out more branches while deadheading prevents the plant from setting seeds. Too much work: Buy annuals that are “self-cleaning.” They will drop their flowers and keep on blooming.
Start some annuals from seed. While it is tempting to purchase annuals as plants in spring, some grow quickly from seed. In a 1957 article, Minnesota Horticulturist recommended waiting until the soil warmed up and then planting, “sweet alyssum, white and violet; calendula, calliopsis, celosia, centaurea, cosmos, dianthus, marigold, nasturtiums, nicotiana, annual phlox, portulaca, and zinnia.” In sun and warm soil, most of these will germinate wthin 10 days and bloom in four to five weeks. l
Plant fuchsia in eastern or northern exposures. Fuschia are among the most dramatic of annuals, especially in hanging baskets, but they can be tricky to grow. In the April 1975 Minnesota Horticulturist, Pete Ascher noted that fuschias need good light but should not be placed where they get a midday scorching. Eastern or northern exposures are ideal. Other tips: Don’t let a fuchsia plant wilt, even just a bit. That’ll slow down vegetative growth. Lastly, to best encourage and maximize flowering, the plant will need a fairly constant, high nutrient supply. Fertilize regularly.
Contain Your Enthusiasm
Line wood planters to avoid rot. Wooden window boxes and other plants are attractive, but to avoid having the wood rot in a few years, insert a metal or plastic liner. That’s what Sis Kelm of Minneapolis did at her lush condo balcony garden that was profiled in a 1992 feature in Minnesota Horticulturist.
Add trellises for height and screening in container gardens. If you are doing your container gardening on a deck or balcony, consider adding a trellis to some of your containers. Covered by vines, such as morning glories, you will have privacy and a sense of enclosure, Sis said.
You don’t have to replace potting mix every year. If you have a lot of containers, replacing potting mix every year can be expensive. It’s not necessary. Some gardeners, such as Ken Hovet of Browerville, who was the subject of an article on growing vegetables in 5-gallon buckets in 2018, dump the soil from their pots all together. “Ken dumps the contents of all the buckets on a tarp and folds the tarp over to cover the pile,” the article noted. “In the spring, he shovels the soil into a cement mixer along with a little fertilizer and water. ‘I fluff it up good,’ he says, ‘and then fill the buckets up again.’
Yes, to drainage holes; maybe to saucers. In an article from the May/June 2005 Northern Gardener, Kerin Marek, owner of Shades of Green Landscapes in Red Wing, encouraged drainage hols in pots to writes, “plants require good drainage for a healthy root system,” and also discourages the use of saucers for this reason. However, gardeners who grow on balconies and have neighbors below them may want to invest in saucers to hold the drips.
What are your favorite tips for growing annuals and containers?