Freeze damage to tree fruit buds and blossoms

The Front Range is expecting a winter storm with temperatures expected to reach the low 20’s Fahrenheit, 3 to 5 below 0 Celsius. This event will likely cause significant bud and blossom death in fruit trees in this area, as well as to other fruits and vegetables. How much damage is determine by the specific plant (apple, peach, grape, spinach, etc) and the development stage.  There are methods to limit or prevent damage, and we recommend you do some research and apply as appropriate/reasonable to your specific plants, location and resources.  Mark Longstroth with Michigan State University Extension has a couple of tables with critical temperatures for tree fruits, which you can find here: http://msue.anr.msu.edu/news/freeze_damage_depends_on_tree_fruit_stage_of_development

This weather event is not expected to out right kill any apple trees on the Front Range, but local conditions and the health of individual trees vary, so it is possible.  We will keep an eye on our trees around Boulder County and certainly take note of this event.

Newly planted apple trees in Apple Valley

Twelve newly planted apple trees are now growing in Apple Valley, just west of Lyons, Colorado. A landowner contacted us a few months ago and we agreed on Central Asian apple trees. All are grafted, some last year, some this year, on Antonovka rootstock, and are therefore full sized trees when grown out. A neighboring landowner heard about the project and volunteered to take three trees, for a total of 12.  It was a beautiful day to be outside planting in beautiful Apple Valley, and the family living on the property did a lot of the heavy lifting to get the trees in the ground and are going to take great care of the trees in the coming years.  The land owner also did a lot of the heavy lifting and, key point here, made the property available for some trees.  The neighbors who took the three trees are master gardeners, and their property reflects the skills and effort required.

Apple Valley still has some apple trees, two in the immediate area, but not nearly as many as in the late 1800’s and early 1900’s.  We are hoping to change that, and are well on the way to doing so with this first planting.  There is a bit more room on the property, so we may be helping to get a few more in the new orchard.  Thanks to everyone involved.

Apple Valley Orchard

Apple Valley Orchard Location

The Andrus Orchard is ripped and disked

63rd Street Farm has ripped and disked between the rows of the orchard on the City of Boulder OSMP Andrus property.  The property was used to produce hay for many years, and the soil is fairly compacted.  This ripping and disking will disrupt the dense roots of the hay grass, loosen the soil and improve moisture penetration/retention.  It will also ease the planting and growing of the cover crop, which we are still discussing.  The ripping/disking is cross slope, so surface water moving downhill will be captured and move into the soil.  The flags in the image indicate tree locations.  Photo taken looking WWS.

IMG_20160311_132351347

New orchard at 63rd Street Farm, plotted and holes dug

The new orchard going in on the Andrus property, owned by the City of Boulder and managed by Open Space and Mountain Parks (OSMP), for 63rd Street Farm is well underway.  Working with 63rd Street Farm, we developed the orchard plan over the past 9 months and have reach two major milestones.  First, the orchard blocks were measured and plotted, using several different colored flags to outline the blocks and locate individual trees, by rootstock and wild/domesticated varieties.  Second, the holes were dug/bored.  The OSMP agriculture team was kept in the loop, ok’d all of the plans as well as provided a work team with bobcat to bore the holes.  The team was composed of the bobcat and operator and a work crew from the Boulder County Sheriff’s Office.  Thanks to both organizations, OSMP and Sheriff’s Office for boring the orchard tree holes.  This happened about a month ago, giving plenty of freeze/thaw cycles to work on the sides and bottom of the holes before the trees are planted in a few months.  This process, the freeze/thaw cycle, is important for this type of soil when holes are bored instead of hand dug.  The boring compacts the clay in the soil on the bottom and the sides.  If the bottom and sides are not broken up prior to planting, the hole tends to form a clay pot, constraining the tree roots and severely compromising the long term health and productivity of the tree.  Had we bored the holes in the spring, immediately prior to planting, we would have had to manually break up the bottom and sides of the holes.

The OSMP/BCSO team bore trees holes on the Andrus Property in late January 2016

The OSMP/BCSO team bore trees holes on the Andrus Property in late January 2016, they are nearly finished, working on the last of the holes in the western block of trees.  Photo is looking NNW

The western block of the Andrus Property, where the wild apple trees will be planted

The western block of the Andrus Property, where the wild apple trees will be planted.  Photo is looking close to due south

 

The orchard as planned will be 231 trees, with a mix of dwarf, semi-dwarf and full sized rootstock, and a wide mix of wild, dessert and multi-purpose apple varieties.  First to fruit will be the dwarf trees, which will be taken out as they are shaded by the full sized trees, in 10 to 15 years.

Next big step, grafting…