Fall & Winter Watering

WHY WATER?

Unlike some parts of the country, Colorado can experience periods of especially harsh fall and winter conditions characterized by dry air, low precipitation, little soil moisture, and fluctuating temperatures. When we experience extended dry periods, there is not enough soil moisture which puts the root system of trees, shrubs, perennials and lawns at risk if not given supplemental water. Plants that are affected may appear normal in the spring but die when temperatures rise in the late spring or summer because their resources have been depleted. Lack of winter water may also make plants susceptible to insect and disease problems.

WHEN TO WATER?

Monitor soil conditions closely from November through March and water during dry periods when there has been no snow cover for two weeks. You need to water when air and soil temperatures are above 40 degrees F, the soil is not frozen and there is no snow on the ground. You should also water mid-day so the water can soak into the ground before freezing nighttime temperatures occur. Don’t forget to disconnect the hose when you are finished watering.

WHAT TO WATER?

Newly planted trees or plants, transplanted plants, evergreens and broadleaf evergreens that loose moisture through their needles/leaves, and shallow rooted trees are especially vulnerable. Lawns, especially newly established ones, can also suffer winter damage and will need occasional supplemental watering to avoid susceptibility to winter grass mites and desiccation. Even established plants should be watered in times of winter drought but can go longer between watering than the categories mentioned above.

HOW MUCH TO WATER?

Most trees, especially when they are establishing their root systems during the first five years after planting, should get ten gallons per inch of trunk diameter. Smaller shrubs (under 3’ tall) should receive five gallons and larger shrubs (over 6’ tall) should receive 18 gallons of water.

WHERE TO WATER?

Water trees to a depth of 12” using a deep root watering device and apply water to all areas beneath the tree and its dripline. Shrubs should also be watered around the base and within the dripline. For newly planted perennials, check the soil conditions 2-3” deep and water around the root ball if the ground appears dry.

WHAT ELSE TO DO?

Winter mulching is another helpful practice to combine with watering. Plants in exposed areas, generally warmer south and west exposures, are subject to freeze-thaw conditions which open cracks in the soil that expose roots to cold and drying.

SOURCES: Colorado State Extension Fact Sheet 7.211 – Fall & Winter Watering http://www.ext.colostate.edu/pubs/Garden/07211.html

Planttalk Colorado™ – Script 1706 – Winter Watering http://www.ext.colostate.edu/ptlk/1706.html

Street Tree Pruning

Unlike most major cities, in Denver, property owners are responsible for the care and maintenance including pruning of their street trees even though the trees are located within the public right-of-way. This requirement is established by the Revised Denver Municipal Code (Chapter 57).Trees Obstructing Sidewalk Passage

As the street trees in Stapleton mature, trimming is beginning to become an issue as branches and foliage start to interfere with safety and ease of pedestrian sidewalk passage. Furthermore, passengers trying to get in and out of cars parked on the street may encounter interference from tree branches.

Improper Sidewalk Clearance

Exceptions are allowed for young trees which would be irreparably damaged by premature pruning. Trees require little if any pruning during the first five years after planting and that pruning should be limited to the removal of dead and broken branches. If pruning is done too soon or too severely, it slows root growth and encourages shoot growth which adds significant stress to the tree and makes it more vulnerable to insects, diseases, and stress from drought. After five years, if a tree is healthy, it should have a strong, established root system and should be pruned every three years, tapering down to less frequent pruning as the tree becomes more than ten years old. The amount of live branches that should be removed varies based on the age of the tree and the growth rate of the species.

 

Once your street trees are established enough to be pruned, consider hiring a licensed arborist with certification from the International Society of Arboriculture to trim your trees so that it is done correctly and does not cause damage to the tree, a valuable asset for your home. If you do undertake trimming yourself, please refer to the Existing Forestry Rules & Regulations governing Trees & Tree Care listed in the resource section below to ensure that proper techniques are followed for the health and wellbeing of your tree. Do not indiscriminately remove branches as this can add stress to the tree. Pruning should be based on pruning objectives (why to prune) and pruning methods (how to prune) which determine the type of pruning cuts to be made. Objectives include reducing the risk of breakage from wind and snow, improving the structure, maintaining health, improving aesthetics, providing clearance, improving view, reducing shade, and increasing flowering and fruiting.

 

Light pruning to remove a few small branches can be done at any time of year. More extensive pruning should be done in late winter to early spring. This is advantageous because wounds close more rapidly if done just prior to when new shoots emerge, there are few active insects and disease spores to infest pruning cuts, and deciduous trees have dropped their leaves so it is easier to see what you are pruning. Lastly, many tree companies offer discounts for winter pruning.

 

What Stapleton Streets & Sidewalks Might Look Like in the Future
What Stapleton Streets & Sidewalks Might Look Like in the Future

For more information:

Revised Denver Municipal Code (Chapter 57) – The City Foresters Ordinance http://www.denvergov.org/Portals/626/documents/Trees/City%20forester’s%20ordinance.pdf

Existing Forestry Rules & Regulations governing Trees & Tree Care – http://www.denvergov.org/Portals/626/documents/Trees/Trees%20and%20tree%20care%20regs.pdf

CSU Extension, Colorado Master Gardener Program, CMG Garden Notes: http://www.cmg.colostate.edu/gardennotes.shtml#pruning
#614 – Structural Training of Young Shade Trees
#616 – Pruning Maturing Shade Trees
#617 – Structural Pruning of Maturing Shade Trees