Fruit bud break progress at the Horticultural Research Center - May 7, 2019

Author: Annie Klodd, Extension Educator-Fruit and Vegetable Production

Bud break at the UMN Horticultural Research Center is moving along slowly due to cool temperatures the past week. This is not necessarily a bad thing; a slower bud break helps keep the buds protected from unexpected late spring frosts for a longer time period, because buds in earlier stages are more tolerant to freezing temperatures.

A week ago, I reported half inch green and tight cluster on several apple varieties, green tip on Alderman plum, and first swell on North Star and Bali cherries.

Here are some photos of bud break this morning (May 7, 2019) at the Horticultural Research Center in Excelsior, Minnesota, west of the Twin Cities.

McIntosh apple entering first pink stage

State Fair apple trailing behind at tight cluster:

State Fair apple at tight cluster

We do not yet have enough growing degree days accumulated for bud break in grapes. The Itasca grape is further along in bud swell than many other varieties like Marquette, but bud break has not yet occurred for grapes in east central MN:

Itasca grape buds one centimeter long, in late bud swell

Marquette is in earlier stages of bud swell, and did not appear to change much from a week ago:

Marquette grape in bud swell

Moongold apricots, which break buds earlier than many other cold climate fruit trees, are in full bloom. Hopefully we do not get a late freeze. The prevalence of late freezes in our climate are a major reason why it is challenging to grow apricots profitably in Minnesota. But if we do not experience a late freeze after today, we should expect a good crop of apricots from this tree:

Moongold apricot in full bloom

Toka plum:

Toka plum at first white stage

Alderman plum:

Alderman plum at tight cluster, almost at first white

North Star, an earlier variety of tart cherry, is further along than Bali tart cherry:

North Star tart cherry at white bud or "popcorn" stage

Bali (Evans Bali) tart cherry is a couple of stages behind North Star:

Bali tart cherry at green tip (bud burst) 

Author: Annie Klodd, Extension Educator - Fruit and Vegetable Production. kloddann@umn.edu