Nevada Public Radio Listen Live

"BBC World Service"
Facebook Twitter Follow Nevada Public Radio

Support Nevada Public Radio
February 18, 2014
Podcasts

DESERT BLOOM: Mulch is for Winter

Listen

Angela

Norm's mulchAll over the world, gardeners know how important mulch is for a successful garden. It’s a multi-purpose landscape essential; in addition to its practical purposes, it has aesthetic value. Covering bare soil with a consistent layer creates an attractive unified theme. It’s an effective way to connect the varied plantings in a landscape. In any climate, and certainly in a desert, mulch is an ecologically sound way to conserve our limited soil moisture and to control weeds.  Almost any mulch material – gravel for desert landscapes, or straw, wood chips, bark, even shredded newspaper for other types of gardens – will work.  Each kind has its most appropriate use. Newspaper’s probably not the best choice for a formal garden, but all mulches serve comparable roles: shielding the soil and the plants growing in it.

Mulch is a very simple way to protect the plant roots and lower stem.  During the Mojave summer, it provides enough shade to protect the soil from the heat of our blazing sun.  With this cooling action, even plants that evolved in environments that are more temperate can grow successfully here in the Mojave.  

Recently I suggested guarding landscape plants by applying mulch in winter. That might be a foreign concept for some people. We know it’s critical for keeping down unwelcome plants and modulating soil temperatures in the summer, but why winter?

This might be less obvious. After all, weeds are generally a smaller problem in the dead of winter; and cooler, shorter days mean that our landscape plants are growing more slowly, if at all, so they tend to need less water. Plant roots experience lower stress when they’re sheltered from temperature and moisture extremes: hot/ cold, wet/ dry. So mulch isn’t only a summer lifesaver, it can benefit plants during the wintertime as well.  Why would mulch be an important consideration for perennial plants like trees and shrubs, not to mention our cool-season vegetables, around this time?

It’s not news to people who live in southern Nevada that desert winters, particularly winter nights, can be surprisingly chilly, even freezing at times. The stress is extreme, especially during those freaky seasons when nighttime temperatures can drop significantly below freezing.

Plants can be astonishingly smart; they have chemicals dissolved in their cells that have much the same function as the antifreeze in a car, or putting salt on a sidewalk to melt ice.  This is the reason why a number of cultivated plants won’t freeze until the temperature reaches about 28°.

Unless they’re perennials with the capacity to go dormant, very few plants survive, much less thrive, when it gets any lower than that, though.

Having said all this, many of our prized horticultural specimens originated in hot, sometimes moist, climates. They haven’t evolved the tools to withstand the challenges of their new desert homes. They scarcely have the capacity to tolerate our relatively mild winters, much less when the temperature drops down lower than the mid 20’s that we can experience.  Despite that, adventurous desert gardeners frequently want to try introducing them.  To keep them alive, we need to adjust their environment.

Let’s view mulch as a kind of protective insulation, something like a thermal blanket, or insulation in the ceiling. For any marginal landscape plants, winter mulch is essential. This is certainly no less important than it would be during hot weather. When we shelter their roots with an additional layer of protection, cold-intolerant plants are less vulnerable to extremely chilly temperatures.  Plants generally benefit when they experience a narrower range of heat and cold.

Over the course of a year, mulch moderates soil temperatures – keeping them warmer in the winter and cooler in summer, playing a similar role as the insulation in our homes. As an element of the landscape, there are choices of materials that can be an attractive addition throughout the garden.

Don’t forget to call the Master Gardener Help line to get details of my expanded “Growing in Small Places” class. In 2014, we’ll cover topics from proper pruning to creating an organic garden. Hope to see you there.

For KNPR’s Desert Bloom, this is Dr. Angela O’Callaghan of the University of Nevada Cooperative Extension.

See discussion rules.

Archives

AngelaSep 30, 2014 | Fountain Grass
A weed by any other name is still a weed even if it doesn't look like one. If only everything in our gardens thrived as well as weeds. Here is Angela O'Callaghan.

NormSep 15, 2014 | Desert Heat
Norm describes a significant casualty of the desert heat. There's going to be a big gap in Norm's Yard and a lesson on the reality of our desert landscape.

AngelaAug 12, 2014 | Organic Pesticides
Choosing a method for ridding your garden of an unwanted guest, be it bug or weed, is not always a simple choice. But the more you know, the better it goes. Here's Angela O'Callaghan

NormJul 28, 2014 | Lose that Lawn
We know, it's a desert out there including every place there's a lawn. Norm Schilling reminds us all the ways he wants you to consider losing the lawn... permanently.

AngelaJul 14, 2014 | Protect Fruit Trees from Birds
If you put a good deal of care into growing fruit trees, there are likely some birds who will take advantage of your effort. Here's Angela O'Callaghan.

NormJul 10, 2014 | Palm Care, Part 2
To keep, or not to keep. Norm Schilling ponders his palm trees, on this edition of Desert Bloom.

NormJun 10, 2014 | Palm Care
Norm Schilling has mixed feelings about how we use Palms in our yards. Full grown palm trees transplanted into the entry way of a mall is a common sight that tells Southern Nevadan's "something" is nearly open for business. He reminds us that those palms come with challenges.

AngelaJun 3, 2014 | Hot Weather Plants
As temperatures across the Valley begin to climb, you might be wondering what will survive in your garden in the months ahead and what probably won't. There are some 'sweet' options. Here's Angela O'Callaghan

NormMay 20, 2014 | Desert Color
Norm Schilling just got back from Belize and has some ideas for lush leaves in your desert yard. He reflects on some well suited plants to provide color and variety in this edition of Desert Bloom.

AngelaMay 6, 2014 | Emerald Ash Borer
Raising a healthy shade tree in the Mojave is not always easy. And if one particular insect makes its way here, it could get even harder. Here's Angela O'Callaghan with Desert Bloom.

NormApr 22, 2014 | The Right Plants
Our current warm spell gives the impression that some plants can thrive when they aren't really suited to our desert. Norm Schilling has some examples.

NormMar 24, 2014 | Spring Garden Party
Spring is here and the garden is blooming . . . so invite some friends to enjoy the rewards of gardening!

AngelaMar 10, 2014 | Lady Banks
If you love roses, but don't care for thorns, you may want to call on 'Lady Banks.' Here's Angela O'Callaghan with Desert Bloom.

NormFeb 26, 2014 | Signs of Spring
It may be February, but if you are paying attention, signs of Spring are visible. Dwarf peach and Mexican plum trees are in bloom. Vibrant Red Spraxis can be seen among the falling Almond blossom. Watch gardening expert Norm Schilling transplant an offshoot. Check out the slide show of photos taken from his backyard.

AngelaFeb 18, 2014 | Mulch is for Winter
Rewards for using mulch in your landscape can be had year-round. Mulch is about mulch more than just "good looks" according to Angela O' Callaghan. In any climate, and certainly in a desert, mulch is an ecologically sound way to conserve our limited soil moisture and to control weeds.

NormFeb 4, 2014 | Investing for Spring
Temperatures are scheduled to stay cool this week, but Norm Schilling finds his yard is ready for Spring. He reflects on techniques to keep older trees healthy even as the surrounding yard may change. Bigger, older trees may need more water.

AngelaJan 13, 2014 | Freezing Temps
If your garden looks like it's been zapped by Jack Frost, there's still a chance that all is not lost. Delicate desert plants can suffer chill damage even when the temperature stays above freezing. Well-established plants should survive.

NormDec 31, 2013 | Leave the Leaves
Just because most of the leaves have fallen from the trees, it doesn't mean you have to rake them all up. Norm Schilling says it's better to use the leaves as mulch to protect the plants and make rich soil. Some woody plants can be pruned now, while others should wait another month or two.

AngelaDec 13, 2013 | Winter Greens
It is the season to enjoy some winter gardening. In Southern Nevada, a cold-snap does not have to mean that your garden is done for. Angela O'Callaghan gives a few cold facts.

NormDec 3, 2013 | Winter Watering
After a recent rain followed by a cold snap this week, Norm Schilling digs in to figure out how much water is needed this time of year. Touch the leaves to get a feel and don't water much at all for the next few months.

© 2014 NEVADA PUBLIC RADIO   
Web hosting facilities provided by Switch.