Tag: dormancy

Tree Profile: Crabapples

Flowering Crabapples (Malus spp.) are common small ornamental trees in the Rose family. These should not be confused with the large-fruited eating apples grown in orchards. Some species are native to North America, but many have come from Europe and Asia. Flowering Crabapples are popular due to their colorful flower, leaf and fruit displays. Their fruits provide an important food source for birds and mammals, although fruits can be messy. There are hundreds of hybrids so exact identification can be difficult.

Many crabapples are riddled with pest issues (chewing caterpillars, rust, scab, and powdery mildew are common) and at some point in the growing season, many trees tend to look ratty and unhealthy. Caring for crabapples usually involves tending to their pest susceptibilities and smart applications of pesticides. Crabapples flower and fruit best if grown in full sun, otherwise too much shade or wet conditions aggravate disease. They have little need for pruning and it is usually done to remove cracked and dead branches or to manage disease. The ideal time of year to prune crabapples is late winter when diseases have slowed and plant defenses are strongest. Pruning should be kept minimal because heavy-handed pruning ALWAYS will respond with prolific sucker/shoot growth.

You will be most successful with a crabapple if you choose a disease-resistant variety, plant in a good location, stay on top of pest issues before they get out of control, and only prune lightly.


Tag: dormancy

Do Trees Need Cold Winter Temperatures?

bloomtwigPeople always think of harsh winters causing damage to woody plants but could anything problematic come from a mild winter? Hardy, temperate trees and shrubs are adapted to survive for up to several hundred years over many different winter intensities. If temperatures hold steady above and/or around freezing and gradually change, there may be no effects at all. However, when we get warm temperatures, greater than 50°F and/or fluctuations from very low to very high and vise versa in a short period of time, there can be problems.

High Temps in Winter, like we had in December, causes some plants to prematurely ‘wake up’ from dormancy and pop out spring flowers. There are some consequences for that come spring such as a later, longer and uneven flower display, reduced energy for growth, resisting pests and adverse environmental conditions (such as drought). This also can affect fruit trees that require adequate chilling hours like apples and pears, resulting in less, smaller, and/or misshapen fruits. Lastly, some pests are suppressed by the cold and without low enough temperatures, they have more opportunity to be active.

Wide, Rapid Fluctuations in temperature don’t allow enough time for plants to re-enter dormancy from which they can endure harsh winter conditions. This abruptness can result in stem cracking, sun scald and twig and bud death from starting to grow during a warm period and then quickly freezing.