Multiple season color change-outs come with their challenges. Early and late-season color plantings are exposed to unpredictable weather and fluctuating temperatures that can threaten the appearance and survivability of your hard work. But calculated risks can pay off big when you properly acclimate the plants and choose the varieties you use wisely.
Prepare Your Plants
Frequent extreme changes of temperature cause major problems for plants and their growing cycle can become disturbed to the extent that the plant dies. Odd weather patterns in the winter will often put plants under stress. Plants purchased from greenhouses and garden centers generally have not been exposed to these conditions or the colder weather outdoors and need to be hardened off.
Plants like loblularia are tolerant of cooler temperatures for early spring or fall plantings.
Photos: Four Star Greenhouse/Proven WinnersTo harden off the plants, simply move them outside to a warm, sunny location for part of the day and gradually increase the length of time they are outside until they have been out all day. Bring them back inside if temperatures are predicted to drop below freezing. Once the plants have become acclimated to the cooler temperatures during the day, leave them out overnight and get ready to plant.
Not all plants will tolerate colder temperatures or a frost even if they are properly hardened off, so careful selection of plants is essential to success. There are flowers that are more tolerant of cooler temperatures and frost and also do not require a long day of sunlight to grow and bloom. Remember to purchase larger plants for early spring or fall plantings than you would for a summer planting. With shorter days and cooler temperatures in the spring and fall, the plants you install will not really grow much so they need to be a good size to fill your planting area.
For spring color, pansies and snapdragons are quite cold tolerant and are frequently used in commercial color plantings. Nemesia and diascia both belong to the same family as the common snapdragon. Both of these plants, although appearing to be delicate and dainty, are rather tough and can easily handle inclement weather.
For fall color plantings, the traditional choices are mums, asters, and flowering kale or cabbage.
To offer your customers something out of the ordinary and differentiate your work from other companies, substitute or add nemesia or diascia to your late season plantings.
Other flowers that are tolerant of cooler temperatures for early spring or fall plantings include butterfly argyranthemum, osteospermum, dianthus, lobularia and primrose. Heuchera (coral bells) are quite cold hardy and although they are grown mostly for their beautiful foliage, they pair nicely with the earlier mentioned flowers. The choice of foliage color is unending, and since they are perennials, they can be pulled and replaced just like an annual, or remain in place all year long.
Even with precautions, extreme cold temperatures can cause damage to soft-stemmed plants. Plants suffering from cold injury need to be cut back and cleaned up immediately as the damaged flowers, leaves, and stems are prone to rotting. Cold-damaged plants can be watered and given a boost of liquid fertilizer to help aid in their recovery.
Working with Bulbs
Fall-planted bulbs such as tulips, daffodils and scilla are a common choice for large areas of seasonal color, but even bulbs are subject to adverse weather conditions. If the winter is unseasonably warm, the bulbs can emerge much earlier than usual, resulting in short stems and flowers that do not open. A deep layer of mulch applied after the soil freezes will help protect the soil from warming too quickly.
Although early and late-season color plantings come with unpredictable weather and temperature challenges, they can be a great revenue supplement and an attractive addition to your regular menu of services. All it takes is some careful planning and wise plant choices.
The author is a certified landscape professional, master certified nurseryman and landscape account manager for Four Star Greenhouse/Proven Winners in Carleton, Mich.