Everything Has A Season
We have all observed the Christmas season starting earlier each year. The day after Thanksgiving once marked the beginning of the shopping season. Now Christmas displays are commonly seen before Halloween. The same phenomenon is happening in the nursery trade. Memorial Day weekend no longer marks the beginning of the gardening season. Instead, garden centers will be stocked with flowering plants by the end of April. A new standard and expectation is being established in the gardening and landscape industry. Consequently, our customers commonly request plants in April. For those customers making this request, typically my reply is "What are you going to do with these plants in April?"
Greenhouse grown stock is forced; meaning it is started in greenhouses in late winter. The plants are physiologically more mature than like species growing outside. Once stimulated to grow in the greenhouse, they are vulnerable to the extreme changes in temperatures typical of weather conditions in April. If transplanted too early, these plants may lose their leaves, go dormant, or even die.
A related concern is the energy intensive nature of greenhouse production. As an environmentally oriented business we strive to minimize our energy use in all aspects of production, including greenhouse heating. Therefore, we try not to push these plants too hard. There is no horticultural or ecological advantage for early production. What is the rush? These are perennial plants to be enjoyed for years to come. Furthermore, warm season prairie species like Little Bluestem and Butterfly Weed are very slow to start in February and March, even in a warm greenhouse. As a result, these plants are not well enough established by April to sell. This is another reason we do not officially open until mid-May. Unlike the garden centers that have their biggest inventory in early May, our availability increases through the season. You will see a greater diversity of plants at our nursery in July, August and September, than in May and June.
You may be wondering when is the appropriate time to plant perennial potted material? Mid- May through October is a very safe window. Some people prefer to avoid the hot summer months in order to reduce the need to water. However, any plant will benefit from supplemental water through its first season, regardless of when you transplant it. Though spring is the time we traditionally think of starting gardens, late summer and fall is a great time to plant. When planting perennials the joy of spring planting and establishing new gardens can go on all season.