Spring 2012 Update

By On April 17, 2012 · Leave a Comment

Frost damage to saucer magnolia bloom

This spring weather has resulted in some abnormal activity in landscapes. We are currently about 2-3 weeks ahead of where things normally are phenologically. Typically the second week of May is peak bloom time here in the Boston area. We are on pace for that to occur the 3^rd or 4^thweek of April. What are the implications of this advanced development?

For those of you with magnolias (star, saucer, etc.) you may have experienced frost damage of blooms. The early blooming magnolias were pushed to flowering much earlier than usual and were hit by below freezing temperatures while many were in full bloom. This resulted in partial to full browning of many magnolia blooms. Although the display may have been cut short, there should be no noticeable damage to foliage when it emerges as it was protected in the buds. While other trees and
shrubs were also in bloom (forsythia, some cherries, purpleleaf plums) or pushing out new foliage (flowering crabapples) during this time, the flower and foliage characteristics of these plants resisted obvious cold-temperature damage.

Frost damage to saucer magnolia bloom

Hydrangeas buds that were swollen or were in early budbreak, however, may have also received some frost damage. This is exhibited by partial browning of early emerging foliage. This foliage will probably remain on plants so be aware of the cause so as not to confuse it with a disease issue or some other physiological cause.

Insect activity is also advanced this year. Tree and shrub insect pests are also many weeks ahead of normal. Control strategies need to take this into account. Winter moth hatch has already occurred and currently caterpillars are mostly 1-2 mm long. Because of the nature of their feeding habit, control measures need to be applied following tree budbreak. We are beginning winter moth control sprays for crabapples already while in past years first applications have been begun at the end of April. Applying controls at a normal years timing will result in heavy feeding damage if winter moth is present in good numbers on your property. Likewise, harder to control

: Small holes in crabapple leaves as a result from winter moth feeding

pests such as scale insects will need to have timing applications advanced this year or controls may be inadequate. Grub activity in lawns and beds is ahead of schedule this year with the grubs coming up in the soil to feed much earlier this year.

Our annual precipation is also below normal. We are coming out of a winter where we received very little snow or rain. Trees, shrubs and lawns are impacted by this. Soils are moisture-recharged in the fall and winter through seasonal precipitation. It is often June before soils begin running moisture deficits. Supplemental watering will be required earlier this season unless we receive timely and more normal spring and summer precipitation.

: Winter moth caterpillar feeding on crabapple leaves

Lawn renovations and spring seeding will likely also be advanced this year. Minimum soil temperatures need to be 55 degrees Fahrenheit for lawn seed germination to occur. Typically it is well into May before we start renovations and seeding. Temperatures currently are around 50 degrees so we are estimating our spring seeding to begin in April. If you renovate lawns too late in the spring you will run into hot, dry weather and adequate establishment will be harder to obtain. If you are planning a lawn renovation this spring you may be well advised to get your irrigation up and running sooner rather than later.

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