Garden Benefits of Snow By Joyce D’Agostino

Photo: Joyce D'Agostino

We’re all aware that getting a good soaking rain or bountiful snowfall helps to relieve drought conditions throughout the year and also helps to keep the field crops and gardens well hydrated and healthy. In addition to the moisture, there are some additional benefits from winter and spring snowfall.

Spring Drought 2021 by Nancy Shepard

 

With all the excess snow and rain we’ve had this spring, I was surprised to see this drought map recently released by the Colorado Climate Center at Colorado State University. Only the upper right quadrant shows favorable conditions from all this spring precipitation. The Standard Precipitation Index (SPI) is a relatively new drought index based only on precipitation. It's an index based on the probability of precipitation for any time scale.

After seeing this I realized that my business-as-usual approach to planting spring annuals needed some tweaking. What are some of the alternatives for annuals that can take the heat?

Cleome ‘Senorita Rosalita’

Known as the Spider Flower, Cleome 'Senorita Rosalita' is easily grown in average, dry to medium, well-drained soils in full sun but tolerates light shade. It does better with consistent watering during the growing season. Once established, it tolerates heat and drought. This cleome is a sterile plant that will not reseed in the garden. It is winter hardy to USDA Zones 9-10 and is grown as an annual in Zones 3-8.

PINK CRYSTALS® ruby grass Melinis nerviglumis
Photo: Plant Select

Melinis nerviglumis is an annual here and many gardeners consider the shimmering heads of bright ruby and silver flowers the most beautiful new contribution to bedding or the border. It sparkles like champagne bubbles. Tips from the pros: Plant larger plants as they will bloom earlier and provide longer bloom.

Silver Dollar Plant Plectranthus argentatus
Photo: Plant Select

The plush, silver, heavily textured leaves of Plectranthus argentatus make a trim mound through the summer months. Very easy and adaptable in a variety of sites and soils, it is considered a xeriscape plant. Excellent as an accent or massed, in containers, in annual plantings or borders. 

Rudbeckia hirta ‘Autumn Colors’

Gloriosa Daisy hybrids are short-lived perennials, sometimes treated as annuals. Often these will survive a few winters or at least self seed. This mid-sized strain produces large brown-eyed daisy flowers for months on end, in a range of bicolor shades from yellow through gold, orange and bronzy-red. An outstanding cut flower. Removing faded blossoms regularly will greatly increase the flowering time.

For a larger list of xeriscape perennials and annuals see:

https://extension.colostate.edu/topic-areas/yard-garden/xeriscaping-perennials-and-annual-flowers-7-231/ 

Freeze, Drought and Damage to Trees by Heather Duncan

A frost-damaged tree. (Courtesy of Colorado State Forest Service)

In early October 2019, we experienced an extreme weather event when from October 9-11 our front range temperatures dropped from highs in the upper 70’s to lows in the 10’s or even single digits before rising again to the mid 60’s.  Most of our trees had not yet hardened off for winter causing a range of damage. While weaker trees may have suffered more severe damage, healthy trees likely weathered this event with minimal damage such as blackening or browning of leaves on deciduous trees or “grizzled” foliage on evergreens. 

Many of our healthy trees hold enough reserves to handle a single event like this so any longer-term damage would necessitate additional stressors and Mother Nature never disappoints!

Over this past winter, we experienced a short period of drought during December and January.  The front range received only three weather events that brought any measurable precipitation during those months.  The dry winter conditions likely added additional pressure to our trees, especially to those that did not receive any supplemental water during this period.  Signs of winter injury might include browning or rust colored needles on evergreens and sun-scald or leaf scorch on deciduous trees.

Photo: Mary Beth Mainero

Photo: Heather Duncan

Normal Needle Drop
Photo: Heather Duncan

And to add this…in April 2020 temperatures plunged again!  While many spring plants can tolerate light freezes or temperatures of 29º Fahrenheit, we experienced another deep freeze just as many trees were budding and beginning to flower.  From April 10-13 our temperatures dropped from highs in the upper 60’s to lows well below freezing and into the teens.  Not only did this freeze result in a Disaster Declaration for our Western Slope from the USDA, many of our other trees around the state, already stressed by the previous drought and early fall freeze, suffered additional damage such as leaf or flower buds being killed or leaf distortion.

Photo: Heather Duncan

But don’t dismay!  While flower buds are gone for this season and you’ll likely have to wait for next year to see those again, most healthy trees and shrubs have enough reserved energy to form a second flush of leaves.  Many of our trees on the front range have already leafed out again.  Here are some tips and resources linked below on how to manage your trees going forward:

·      Water appropriately:  if there isn’t rain or snow in the forecast, water the root zone to a depth of around 12 inches once or twice per month (even over the next winter) however be careful to not overwater

·      Mulch: applying mulch under a tree may help reduce moisture loss and competition from turf and improve moisture penetration into the soil

·      Hold off on the fertilizer: wait until the tree has fully re-leafed

·      Watch and wait for continued leaf and needle emergence:

o   check for soft/pliable limbs and buds (alive) or dry/brittle limbs and buds (dead)

o   healthy trees will likely form new buds this summer and over the coming seasons will fill in the gaps

o   only prune out dead branches after new growth has emerged and do not prune any living tissue

And for additional information, as always, the Jefferson County Colorado Master Gardeners are here to support you.  Please visit our website at https://cmg.extension.colostate.edu/.

Additional information is available:  Western Slope, Woody Plants, CSU-Woody Plants, 
ColoStateForestService 

Your Landscape and Water by CSU

Colorado State University

Is your landscape ready to work for you to beautify your home and be able to withstand drought conditions?  The following documents the many ways landscaped outdoor areas contribute to the quality of life and property values in Colorado.

Colorado State University did a study of landscaping contributions to the environment, quality of life and property values in Colorado, which should be considered when planning for drought.

Low Water Stresses Urban Trees

Hot Wings Tatarian Maple, photo courtesy Denver Post

Information excerpted from: Lack of Water is Key Stressor for Urban Trees, North Carolina State University. Click on the link for the article in its entirety.

A recent study found that urban trees can survive increased heat and insect pests fairly well - unless they are thirsty. Insufficient water not only harms trees, but allows other problems to have an outsized effect on trees in urban environments.