February 12, 2012
Mild Winters, Flowers, Insects, & Disease
Last week we looked at weeds and mild winters, now let’s look at fruits flowers and fungi. There are some advantages to a mild winter, flower buds on fruits trees are less hardy than their vegetative buds, so a mild winter will allow more flowering and later more fruit. Though we generally want to get as much fruit as possible, too much fruit can mean not only broken branches, but smaller less succulent fruit, so be sure to thin those fruits and not over burden the fruit tree. The same applies to our flowering landscape shrubs. Forsythia will bloom from the ground to the tips when winters are mild with no thinning necessary
On the down side, over 80 percent of our plant diseases are caused by fungi. A mild winter allows those fungal spores and structures to live on more, decaying moist plant parts. The overwintering fungal structures will be in the leaf litter waiting to strike again next spring during cool, wet weather. Raking and removal of as much of that leaf litter as possible will reduce the spores available and there for a huge impact on disease pressure this coming spring. For this reason, recommend early clean up of perennials and fallen leaves in beds this year, removing spent plant parts and weeds, to remove the overwintering fungal structures and lessen the disease pressure.”
A mild winter will not affect populations of insects routinely surviving much colder winter temperatures. It will have an impact on insects that typically move into northern areas from the south, or neighboring states that do not overwinter locally. A mild winter will allow more of them to survive in their normal habit before migrating . For those insects that normally overwinter in northern climes, it would take a very cold winter over an extended period to lower those pest populations. Insects can overwinter as eggs, larvae, pupae or adults using a variety of tactics to survive.
Though the implication is that spring populations such as flies and mosquitoes could be higher, a late freeze in let’s say March might actually reduce these populations in our area. Alternately, many birds feed on these insects and may also limit the mosquito population which is why creating and sustaining landscapes that promote bio-diversity and create homes for beneficial insects is so important. No matter what kind of a winter we end up with, gardeners know that diseases and insects will develop right along with our landscape plants, so be on the lookout early and often for potential problems.
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