December 2023


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News for Norther Colorado and the world

Tuesday, December 5, 2023

Master Gardeners


Gardening Article

By: Susan Perry
Colorado State University Extension Master Gardener in Larimer County

Get a Jump on Next Spring’s Garden Right Now

A few years ago, I discovered a great use for some of my leftover vegetable seeds. I was trying to plant lettuce for a fall crop, but waited until mid- to late August to plant the seeds. By the time the weather got cold, my lettuce plants were about 2” tall. Hmmm, I thought, they’re not going to survive the winter. Oh well. And then I covered the whole bed with leaves, included it in my winter watering, but generally forgot about it. When spring came along and I was cleaning the leaves out, I discovered my little lettuce plants had made it. Well, I was pretty sure they’d produce awfully bitter lettuce if allowed to mature, so I turned them under…. all but one, which escaped my notice. Imagine my surprise a few weeks later when I went outside to plant lettuce seedlings I’d purchased to see the single lettuce alive. I left it there, planted the store-bought seedlings nearby, and waited to start harvesting lettuce. Amazingly, the single, over-wintered lettuce was able to be harvested weeks earlier than the purchased seedlings. So, my accidental late planting of lettuce led me to a new use for my leftover seeds: fall planting vegetable seeds to get an earlier start in spring.

After this accidental discovery, I did some research and then tried the same thing with pea seeds. Just as I would if I planted peas in spring, I soaked them overnight and planted them – in late October, covering the bed with leaves and including it in my winter watering. I’ve done this for several years successfully, with about 90% germination early in the spring when the ground is warm enough. Conventional wisdom says plant your peas on St. Patrick’s Day, March 17th. This year, my baby peas were between 1” – 2” tall by March 12, 2014 and at that time, I planted just enough peas to fill in the gaps where nothing germinated.

It won’t work for all my seeds, but it has worked for lettuce and peas, and would probably work for other things like spinach, chard, cabbage, and kale. I’m certain it wouldn’t work for warm-weather vegetables like tomatoes, peppers, or beans. The trick is selecting cold-hardy vegetables that will go dormant during the winter and start growing again once the soil temperature becomes warm enough in the spring. Some protection, such as a thick layer of leaves, is required to help insulate the seeds/seedlings during extremely cold weather.

Garlic works when planted in the fall in Colorado, so onions starts might too, as long as they’re planted in a well-drained location. Radishes, carrots and beets that are mature can be harvested even after the ground freezes—although it may require a chisel—but the taste will be fine. However, these root crops will become inedible if subjected to freeze-thaw conditions and should be completely harvested by early spring before the plants send up a flower stalk, when they become bitter. So it may be best to plan to harvest them for use in holiday dinners. Often the cold fall/early winter temperatures result in a sweeter flavor.

One of the challenges of planting in late summer is germination: the warm air and soil temperatures or drier conditions can result in inconsistent germination of cold-loving vegetables. Ensure soil is consistently moist and mulch to help keep soil temperatures cooler. Conversely, in the winter, mulch, leaves, or a blanket of snow will help keep the soil temperature a little warmer.

When planting in fall to overwinter for a spring harvest, keep in mind the location of your garden. Low spots tend to be colder and are places where water may accumulate. Good drainage is important during the winter to enable plants to survive until spring. Be sure to provide water at least monthly when there’s no snow cover or during extended warm winter periods to avoid stress due to our drying winter winds.

Another challenge comes during winter and spring, when we experience surprise cold snaps (think February 5-6, 2014 when daytime temperatures were zero). In Colorado, we can have 50 degree days followed by single degree days, so keep extra leaves or other mulch handy. You may also need floating row covers for an added layer of protection. As nighttime temperatures rise above freezing consistently, gradually remove some of the leaves/mulch to allow sun to reach the plants.

In the end, it is a gamble but I always ask myself, what’s the downside? I wasted a little time and used up some leftover seeds. The upside is I might have some homegrown vegetables earlier in the spring.

Pea Seedlings in March taken by Susan Perry

Photo of pea seedlings taken by the author, Susan Perry.


Gardening Tips

By: Anne Wuerslin
Colorado State University Extension Master Gardener in Larimer County


One can grow grapes in the Colorado home garden. Plant Select® Saint Theresa grape vine is a hardy plant for our alkaline soils, producing nearly seedless clusters of table grapes on one-year-old wood. As with all grapes, proper pruning and trellising is necessary for good production. The single curtain technique is a method for establishing leader and side branches for new plants over the first seasons of growth. Refer to Growing Grapes in the Colorado Garden: CMG Notes #764 for instructions, which can be found at

One person’s weed is another person’s salad. Common purslane (Portulaca oleracea) is a fleshy ground-hugging annual with red stems and a single taproot resembling a jade plant. With rain, it will spring up just about anywhere, even in the cracks of your driveway. It usually escapes preemergent herbicides. Best control measures is to pull it out by the taproot and do not let it go to seed. It is edible, with a taste resembling spinach or watercress. Don’t eat purslane which has been treated with chemicals. Since it’s a summer annual, it will die with the first frost.

Take advantage of end of summer perennial and shrub sales. Plants benefit from the warm soil of late summer to establish good root systems before going dormant. The exception is evergreens, which do better if planted in the spring. Most perennials are in survival mode come late August—deadhead and water, leaving seedheads of hollyhock, columbine, mallow, and foxglove for reseeding.


Gardening Q&A

By: Illeane Podolski
Colorado State University Extension Master Gardener in Larimer County

Question: What are some native flowers and shrubs that I can grow in the Front Range?

Answer: There are so many wonderful native plants for this area which will fit into the Foothills life zone (5,500-8,000 feet), most being dry land plants. This is an important factor to know when purchasing native Colorado plants. Many perennials have vibrant, rich color such as the Callirhoe involucrate, the purple poppy mallow; Gaillardia aristata, the blanket flower; Penstemon strictus, the Rocky Mountain penstemon, and Zinnia grandiflora, prairie zinnia. Refer to Colorado State University Extension Fact Sheet #7.242 Native Herbaceous Perennials for Colorado Landscapes for an in-depth list of perennials at Some good choices for native shrubs, depending on your landscape design, would be Acer glabrum, Rocky Mountain maple; Amelanchier alnifolia, serviceberry; Cercocarpus montanus, mountain mahogany; Ribes aureum, Golden currant; or Arctostaphylos patula, the Manzanita bearberry. Refer to Colorado State University Extension Fact Sheet 7.422 for the specific growth habits of these and other shrubs.

Question: What are some benefits to using native plants in the landscape?

Answer: We can all be wowed by the beautiful, tropical colors of non-native plants such as mandevilla, bougainvilla and azaleas, but these don’t fit into a sustainable Colorado landscape. Our gardens can have these beautiful colors using native plants. Using naturally adapted plants to Colorado’s climate, soil and environmental conditions allows us a long lasting and cost efficient addition to our landscape. When planted in the correct site, imitating their natural habitat, these herbaceous perennials require less water, fertilizer and other cultural factors that help reduce maintenance needed for their growth. Once established, native plants conserve water for our communities. They create a wildlife habitat for many varieties of birds, insects, butterflies, and mammals, a great benefit that we can actually see from our own backyard. Landscaping with native plants on a large or small scale helps to keep biodiversity that would otherwise be lost. This use of landscape-wise planting highlights Colorado and makes it visually distinct from other parts of the country.

Question: How should I amend my soil for growing native plants?

Answer: Many native plants can be grown with success in unamended soils. One of the great things about these plants is that they don’t require nutrient rich, high organic content soil. One of the most important features for the soil is to be well-drained for the native plants. Making a small berm or small hill, and planting on top can also help improve drainage. If amending is needed for clay soils, add 10 percent compost and 15 percent small aggregate by volume and incorporate into the root area. If you have excessively well-drained sandy or rocky soil, amend by adding three percent compost by volume.


More Gardening Q&As

By: Bob Faris
Colorado State University Extension Master Gardener in Larimer County

Question:What should I do to prepare my garden soil for winter?

Answer:Imagine holding over 200 billion living organisms in your hand! One cup of soil contains approximately 200 billion bacteria, 20 million protozoa, and 100,000 meters of fungi, 100,000 nematodes, and 50,000 arthropods. Your soil is alive! Of the 1-5% organic matter found in your garden soil, 0.2% includes living organisms. The harvest you enjoy can be amplified by working together with these billions of friends beneath the soil surface.

These soil organisms can be grouped into three categories: 1) organisms that are beneficial to plants—directly or indirectly, 2) neutral organisms—those whose activities have no affect on plants; and 3) organisms that are harmful to plants. The organisms in your soil form what is known as the “Soil Food Web” and is the basis for healthy living soil.

So what should be done to support these living organisms and how can we help them to remain healthy and maintain a beneficial sub-surface environment? These organisms need to be fed. Adding compost and organic matter to your garden will accomplish this. Lightly broadcasting a cover crop in late fall and allowing these plants to overwinter will provide organic matter to your soil. A blend of buckwheat, peas, vetch, and rye will create a green manure feeding your soil organisms. Avoid rototilling or the use of pesticides. Overuse of pesticides can be harmful to many of these members of the food web and rototilling will destroy the mycorrhizae and soil structure.

For more information about both the soil food web and how to maintain a healthy living soil go to CSU Extension Garden Notes #212 “The Living Soil” at

The authors have received training through Colorado State University Extension’s Master Gardener program and are Master Gardener volunteers for Larimer County.

Larimer County is a county-based outreach of Colorado State University Extension providing information you can trust to deal with current issues in agriculture, horticulture, nutrition and food safety, 4-H, small acreage, money management and parenting. For more information about CSU Extension in Larimer County, call (970) 498-6000 or visit

Looking for additional gardening information? Check out the CSU Extension Horticulture Agent blog at for timely updates about gardening around the state.

Visit PlantTalk Colorado ™ for fast answers to your gardening questions! PlantTalk is a cooperation between Colorado State University Extension, GreenCo and Denver Botanic Gardens.


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