By: John Katterjohn
The first day of Spring is generally associated with the equinox which occurred this past March 20th. That’s just fine for the calendar but weather patterns almost never cooperate. After a long winter people get stir-crazy and long to get outdoors and plant flowers. I noticed three weeks ago that the big-box stores had fully stocked their nursery yards with tender plants straight out of the greenhouse. Wow, put on the brakes! As I write, there is a freeze warning for tonight.
Putting out tender annuals this time of year is very inadvisable. First of all, these new plants have been raised in controlled conditions in greenhouses. They are used to filtered light and warm temperatures. The tissues in these plants are soft and quite fragile and do not adjust to outdoor conditions upon planting. A period of acclimation is required for true success and survival.
Secondly, most of these tender annuals are not cold hardy and will definitely not survive frost, let alone a freeze. Even hardy annuals, if planted outside directly from the greenhouse, will not perform. Again, it’s a matter of acclimation.
Warm season annuals will simply not work. Cold hardy annuals will succeed if they have been properly ‘hardened off.’ This process requires a transition from greenhouse conditions to an intermediate stage where light and exposure are gradually increased. Usually it requires two to three weeks to properly ‘acclimatize’ a plant for outdoor planting. This can be accomplished by proper micro-climate staging either at the greenhouse supplier level or at home utilizing a bright, unheated garage area or cold frame. This sounds like a lot of effort, and it is. But the results are well worth it. I suggest buying bedding plants directly from a greenhouse where these techniques are utilized. A close relationship with an independent garden center will enhance the gardening experience in many ways.
So, what can we plant right now to give us early color in the garden? Everyone is familiar with pansies and violas. They perform well and certainly add a splash of color.
There are other plants that can be used as well. Certainly for bold foliage color there are the hardy greens of certain vegetables, such as ornamental kale, cabbage, and chard. The different varieties of lettuce offer excellent foliage color as well. Dusty Miller is very hardy and adds the bold silver-white for color contrast.
For flowering plants consider trying snapdragon, Verbena Canadensis, Primula, alyssum, Dianthus, and Ranunculus. Marginally hardy perennials can be used too, such as Delphinium, Campanula, and Centaurea.
Just remember, no matter what plant you wish to plant outdoors in the early spring, it must be cold hardy and ‘hardened off.’ I am constantly reminded of the story one of our growers tells me every year. Every spring people go to his greenhouse, buy tender plants, put them in the ground too early, and return to the greenhouse several weeks later asking why the plant was dead or not growing. Lesson well worth noting. Start by planting hardy annuals, wait until the plant is hardened off, plant at the right time, and plant well.
Happy gardening, and, enjoy those bulbs that you planted last fall. They are the real spring flowers of the cultivated garden.