An ongoing series of informational entries
Overwatering? Know the Signs!
April 15, 2020
Over watering plants is one of the biggest issues we see in gardens today. When plants don’t look healthy it is tempting to give them more water and
often this is a mistake. A mistake not easy to diagnose because in many instances too much water mimics the signs of too little water. Below are six
signs you can easily recognize to determine if you are giving your plants too much water.
1. Your plant is wilting but it looks like it has plenty of water
The roots of plants take up water and also oxygen to survive and thrive. Over watering, in simple terms, drowns your plant. There is space between the particles of soil in your garden. Oxygen fills this space. Soil that is constantly wet won’t have enough air pockets and plants will not be able to breathe by taking up oxygen with their roots. When this occurs, your plants will wilt (giving the appearance of too little water) even though the soil is wet.
2. Are the tips of the leaves brown?
One of the quickest, first signs of overwatering to observe occurs at the tip of the leaf. If the tip of the leaf is turning brown this is a sign of over watering.
3. Are the leaves turning brown and wilting?
Leaves turn brown and wilt when plants have too little and too much water. The biggest difference is too little water will result in the leaves feeling crispy when you hold them in your hand. Too much water and the leaves will feel soft and limp in your hand.
4. What about edema?
When roots of plants absorb more water than they can use, water pressure begins to build in the cells of the leaves. The cells will eventually burst, killing them and forming blisters and these areas will look like lesions. Once the blisters erupt, tan, brown or white warty growths begin to form where the blisters originally were. Plus you will see indentations forming directly above the growths on the top sides of the leaves.
5. Yellow leaves?
Stunted slow growth with yellowing leaves is a symptom of over watering.
6. Leaf fall prematurely?
Leaf fall occurs in both situations of too much water and too little water. When both young and old leaves are falling prematurely combined with buds not opening, this is a sure sign of too much water. Check your soil regularly. Don’t be afraid to push you finger into the soil and see how moist it is an inch or two down. If the soil is moist and you have some of the conditions above it’s a sign to reduce your water. Also, many stores sell inexpensive and accurate moisture meters. You simply insert them in the root ball and they will tell you how much water is in the soil. This is a simple and inexpensive tool that will take much of the guess work out of watering your landscape.
Remember, it's always best to feel the soil before watering. If it's moist or damp, hold off, check it again later or the next day, make sure you let them get slightly dry before you water!
Why Grow Native Shrubs?
January 15, 2020
Colorado native shrubs and grasses provide many benefits for home and commercial landscapes. They are naturally adapted to their specific Colorado climate, soils, and environmental conditions. When correctly sited, they can be ideal plants for a sustainable landscape that requires reduced watering, fertilizing, and pruning. Another benefit of using Colorado natives in landscapes is that it attracts a wide variety of wildlife including mammals, birds, and butterflies. Rapid urbanization in the state is reducing biodiversity as habitat is removed for building and road construction. Landscaping with natives on a large or small scale can maintain biodiversity that otherwise could be lost to development. Colorado nurseries are starting to carry more native shrubs all the time, it’s best to purchase one from a grower if possible. Collecting them from the wild reduces biodiversity and causes a disturbed area that may be invaded by weeds. Native shrubs often don’t have as great a visual impact in the container or immediately after planting as do traditional species. Over time, they will reward the homeowner with their natural beauty and other benefits.
There are several factors to consider in designing a native landscape. Due to Colorado’s wide variation of elevation and topography, native plants are found in a variety of habitats. To maximize survival with minimal external inputs, plants should be selected to match the site’s life zone and the plant’s moisture, light, and soil requirements. Even if a plant is listed for a particular life zone, the aspect (north, south, east or west facing) of the proposed site should match the moisture requirement. For example, a red twig dogwood, which has a high moisture requirement, should not be sited with plants of dissimilar water needs. Similarly, a red twig dogwood should not be planted on a south-facing slope, where a significant amount of additional moisture would be required. Growing native shrubs does not exclude the use of adapted non-native plants. There are many non-native plants that are adapted to Colorado’s climate and can be used in a native landscape if moisture, light, and soil requirements are similar. Even if a site has a non-native landscape that requires additional inputs (such as an irrigated landscape on the plains), dry land native plants can be used in non-irrigated pockets within the nonnative landscape. These native “pocket gardens” can be in areas such as parkways and next to hardscapes that are difficult to irrigate. Some communities regulate landscape appearance or the type of plants which may be used. So before completing a landscape design, check with local authorities, including homeowner’s associations, to discover any regulations that may affect your design.
Life Zones of Colorado can be divided into five life zones that are broadly defined by the plant communities that occur at the approximate elevations described below. The Plains life zone, 3,500 to 5,500 feet, is in eastern Colorado where most Colorado’s population resides. It is dominated by grasslands and streamside cottonwoods. In western Colorado, the Upper Sonoran life zone is located at altitudes below 7,000 feet, and in the San Luis Valley, below 8,000 feet. This zone is characterized by semi desert shrub lands and piñon pine-juniper woodlands at its upper limit. The Foothills life zone occurs from 5,500 to 8,000 feet and is dominated by dry land shrubs such as Gambel oak and mountain-mahogany, and, in southern and western Colorado, piñon-juniper woodlands and sagebrush. The Montane zone consists of ponderosa pine, Douglas fir, lodge pole pine, and aspen woodlands at elevations of 8,000 to 9,500 feet. Dense forests of subalpine fir and Engelmann spruce dominate the Subalpine zone at 9,500 to 11,500 feet. The Alpine zone above 11,500 feet is a treeless zone made up of grasslands called tundra. Species requiring medium to high moisture occur along watercourses throughout all zones.
Successful establishment of native shrubs may require supplemental moisture after planting. Once established, the watering frequency can be reduced or even eliminated if the plant was sited in its native environmental conditions. Container-grown shrubs can be planted at any time during the growing season. Container-grown native shrubs are often grown in a soilless mixture of peat and bark, so the planting site should be amended with some organic material. Another option would be to carefully wash off the media from the container grown plant and plant it bare root. Using native shrubs offers many benefits in addition to reduced maintenance. Natives are part of our natural heritage and the ecosystems of Colorado. Native plant communities make Colorado visually distinct from the eastern, southern or western United States. Native plant gardens are wildlife habitats and each plant contributes to the biodiversity of the state.
Composting Made Easy!
December 15, 2019
Compost is easy to make. Essential composting ingredients include organic matter, water, air and nitrogen. Research indicates that soil or compost starters aren’t essential to successful composting, because organic matter naturally contains the necessary decomposing bacteria.
Oxygen and water are critical elements in the composting process. To speed decomposition, moisten materials as you place them in the compost bin. Keep compost moist, but not waterlogged.
Oxygen penetration is key to decomposition. Infiltration rates are a factor of particle size and bin size. For fine materials, a three foot by three foot by three foot bin works well. For coarser materials, like fall leaves, a bin five to six feet square allows rapid heating and faster processing.
Don’t finely chop or pack compost materials, because it restricts oxygen infiltration. If your compost smells obnoxious, it means the materials are packed too tight. To fix the problem, mix in coarser materials to allow better oxygen penetration.
Active compost reaches temperatures ranging from 70 to 130 degrees Fahrenheit in the center of the compost. Disease organisms die at 122 degrees Fahrenheit. Heating is essential, because it stimulates the bacterial process and helps keep the interior of the compost free from weed seed and plant-disease organisms. Some gardeners turn compost regularly to ensure that all materials are heat processed. Frequent turning speeds decomposition, but isn’t required to make compost.
In Colorado, it’s best not to turn compost after December. Turning allows valuable heat to escape, and may stop processing in cold weather. To restart active processing, turn and mix in fresh materials with the winter compost.
Processing occurs faster when materials are mixed together, rather than layered in the bin.
Compost is ready to use when it has shrunk to one-half its original volume, has lost the identity of the original material, and has a pleasant earthy smell.
What are Microclimates?
November 14, 2019
The successful mountain gardener learns to exploit or create microclimates. For example, gardens placed in full sun (southern exposures) will have a longer, warmer growing season than other exposures. These warm or hot microclimates are the places to experiment with plants that need more heat during the growing season to come into flower before frost. If the site is protected in the winter, this is also a place to experiment with less hardy plants.
Another good site for more tender plants is in front of rock formations or walls (natural or created) where the thermal mass can raise winter temperatures. Because plant growth is slowed by cool mountain soil temperatures, creating a perennial bed that slopes towards the south or using raised beds will cause plants to grow faster and emerge earlier in the spring due to the increased soil temperature. These plants may be vulnerable to late spring frosts.
Gardens on south-facing slopes are warmer and drier than gardens on north facing slopes of the same valley at the same elevation. Some mountain areas have a reliable blanket of snow over much of the winter. This acts as insulation and may allow less hardy plants (zone 5 or 6) to overwinter. Snow blankets can be encouraged in specific locations by putting up a snow fence; this will cause snow build up on the lee (downwind) side of the fence. This same snow blanket, however, may cause some xeric plants to rot out during the winter, even if they are cold hardy.
Also consider the flow of air; at night, cool air drains down to low spots. Valley floors may be over 10 degrees F cooler than surrounding gardens on hillsides above the valley floor. Strong winds can cause plants to dry out. Desiccation can be reduced by using fences, trees, or shrubs to create a wind barrier.
Can You Grow a Beautiful Garden in the Mountains?
October 15, 2019
There is no doubt that gardening in the mountains can be challenging, particularly above 7,500’. Sunlight is usually of high intensity and the humidity generally is low. Combinations of cool nights, a short growing season, drying winds, steepness of slopes, aspect, topography, and soil all influence how well plants perform in this climate. Wildlife can also be an issue. Most of these challenges can be overcome with proper site preparation and plant choices.
To determine where to plant your garden, first evaluate your site. The best place to grow flowers is in a site that already supports some grass, wildflowers, or even weeds. This will usually be in a fairly sunny, open area. If the area has weeds, control them before planting something new.
Aspen groves are an ideal environment for many plants, but other open areas also work well. If dense evergreen trees cover your desired garden area and there is little vegetation growing underneath, most plants are unlikely to thrive. It may be necessary to remove the conifers and add organic matter to make these areas plantable. Likewise, if the soil is very rocky and there is no existing vegetation, increasing the organic content of the soil is critical.
There are two major types of soil found in the mountains. Light-colored decomposed granite soils, are low in organic matter, dry out quickly, and do not absorb heat well. They are usually high in most nutrients except for nitrogen. Clay soils are also high in nutrients, but generally have poor drainage.
Soil preparation is often the key to growing healthy plants in the mountains, particularly for non-native plants. Native plants are often adapted to leaner soils (lower in organic matter), and may ‘flop’ or have a shorter life span in well-amended soils. In general, it is beneficial to add organic matter to any type of mountain soil, although in poorly drained soils it is best to add some each year, rather than all at once, to avoid salt buildup. Incorporate 2 to 3 inches of organic matter (or 3 cubic yards per 1,000 square feet of garden), such as alfalfa pellets, compost, or aged manure, to a depth of 6 to 12 inches.
Avoid using Colorado mountain peat, as it is a non-renewable resource, has too fine of a texture, and is alkaline. It is best to work organic matter into the entire area that will be planted. If this is not feasible, dig a larger than necessary hole, and amend the backfill with 20 percent soil amendment. This also helps to prevent a ‘soil texture interface’ when planting nursery-grown container plants. The soil around the roots in a container is often high in organic matter, while the native soil can be lower in organic matter and may be a different texture. This soil texture interface may cause a zone beyond which the roots will not grow. Test the soil after adding organic material for nutrient deficiencies.