Posts Tagged: uc anr
With only a few short weeks between Thanksgiving and Christmas and two very similarly looking plants, you may be wondering whether the gift a loved one gave you for Christmas is a Thanksgiving cactus or a Christmas cactus. (Many sold in local nurseries and large box stores this past Christmas season were actually Thanksgiving cactus (S. truncata), pictured below). While both are native to tropical regions of Brazil, host a wide array of flowers ranging from the more traditional pink hues to newer hybrids showing off white, red, yellow, and purple, they have different bloom periods. The Christmas cactus (Schlumbergera bridgesii), blooms about a month after the Thanksgiving cactus.
The Christmas cactus also has slightly different projections on its leaves, which are more scalloped and less pointed that the projections on the Thanksgiving cactus. Is yours still not in flower and not in the holiday spirit? Both species require cool temperatures and longer nights for about a month in advance of their flowering period. Both plants bloom optimally when grown outdoors when cool night temperatures dip`into the 50s and shorter nights reduce daytime light to 10 -12 hours in a 24 hour cycle. They can also be grown indoors in pots if kept in a cool dark area with no light between 5 pm and 8 am. During daytime, they prefer bright, indirect light. Full sun can cause the leaf segments to turn dark red. Both species require good drainage but, even though they are in the cactus family don't let this fool you! They need adequate moisture - particularly during boom- and cannot make it through long, dry periods without supplemental water. Unlike most houseplants, they prefer to feel snug in their pots, almost to the point of enjoying being slightly pot-bound.
Happiest of holidays however you choose to safely celebrate them this year!
Welcome to another “New Normal!” Due to climate change resulting in hotter, drier conditions and reduced snowpack, the occurrence of a “fire season” which traditionally occurred from May through October is becoming a misnomer, with fire occurring throughout the year. The severity of what may lie ahead over the next several months was highlighted in a recent tweet posted by CAL FIRE: “Compared to last year, California has seen over 2,650 more fires and a nearly 2000% increase in the acres burned year-to-date (January 1 – September 7), across all jurisdictions.”
Indeed, Fall often hosts strong offshore winds that can quickly spread destructive fires, exacerbated by the impacts of climate change. What can you do to help ensure ‘defensible space' that increases the safety of your family, pets and property in fire-prone areas? First and foremost, select and properly maintain fire-resistant plants augmented with hardscapes and fire breaks extending from your home to at least one hundred feet outward. (This also helps ensure access to your home by firefighters and other first-line responders in the event of a fire or other life-threatening event.)
Vegetation chosen for your defensible space should have low flammability and can include trees and shrubs along with herbaceous plants. Allowing adequate space between woody plants is important to avoid a continuous fuel path (fuel ladder) where fire starting at ground level can climb to the top of a tree and spread from tree to tree.
1. Follow these ‘defensible space' guidelines to reduce the risk of fire spread and damage:
Zone 0 (first 5 feet from structures): avoid anything combustible including woody plants, mulch, woodpiles, trellises, and stacked items. Instead, add walkways and mulch and other hardscaping made from pebbles and rocks, pavers, rock mulch, or pea gravel. Include a 6-inch noncombustible area extending from the ground to the exterior siding of structures.
Zone 1 (5-30 feet from structures): Eliminate fire spread by ensuring adequate space between trees, removing lower branches. Consider adding irrigated groundcovers or mowed grass or hardscapes between these plant groupings, as well. Properly maintain plants and remove dead portions of plants.
Zone 2 (31-100+ feet from structure to the property line): Concentrate on reducing the density of plants to slow the spread of fire and to reduce the height of flames. Woody plants should be spaced (as illustrated below) to prevent fuel ladders.
Defensible Zones (source: National Fire Protection Association, nfpa.org)
2. Remember that even a so called “fire-resistant” species that is under-watered or otherwise poorly cared for can be highly combustible. The conditions under which the plant is grown influences its fire-resistance more than the species itself. However, plant species high in wax, oil, and resins such as conifers tend to be highly flammable while manzanita and ceanothus (California lilac) are less so.
3. Avoid planting or spreading invasive species. While invasive plants are never recommended in any landscape, they are especially problematic in natural areas prone to wildfire. Once established they can fuel fire as well as crowd out native vegetation and associated habitat. Refer to the California Invasive Plant Council website for more information and specific examples and plants to avoid (www.cal-ipc.org).
4. Follow recommended planting and pruning guidelines to prevent both horizontal and vertical spread from tree to tree. Horizontal spacing is directly related to the slope of the land and the height of the vegetation.
Photo above (courtesy of CAL FIRE) is a diagram to help you determine minimum horizontal clearance for tree and shrub placement to reduce fire risk.
Photo above (courtesy of CAL FIRE) shows a 5' shrub near a tree. In this example, 15' of clearance (3 x 5') is needed between the top of the shrub and the lowest tree branch to prevent a fire ladder.
5. While fire-resistant natives and adapted non-natives greatly reduce your chance of losing your home and property to wildfire, all plants will burn under favorable conditions. Ensure that plants receive adequate irrigation.
6. Rather than applying organic mulch near your home, use non-flammable materials such as stone and pebbles. Granite pathways are also suggested since they provide a fuel break. Firewood and propane tanks should also be kept away from your home.
CAL FIRE “Ready for Wildfire”: https://www.readyforwildfire.org/prepare-for-wildfire/get-ready/defensible-space/
Drill, S. et al. (2009), S.A.F.E Landscapes: Southern California Guidebook, UC Cooperative Extension: https://ucanr.edu/sites/SAFELandscapes/files/93415.pdf
UC ANR “Preparing Home Landscaping for Fire”: https://ucanr.edu/sites/fire/Prepare/Landscaping/
What do ice cream, potato chips, Scotch and Spanish Broom, and Tree of Heaven have in common? While they're all tempting to indulge in, less is more. In fact, plants such as Scotch, Spanish Broom, Tree of Heaven, Pampas Grass, Green Fountain Grass, and dozens of plants are all considered invasive plants in California. Simply put, they should not be planted. There are some great alternative plants that are better choices listed at the end of this blog.
Truth be told, I admit to falling madly in love with the Spanish Broom (Spartium junceum) shrubs adorning Highway 18 on my drive from San Bernardino to Lake Arrowhead in early spring 1984 right after my job interview for my current position. Being a “wet behind the ears” recently hatched graduate student from the Midwest I was truly in awe of their lovely yellow blooms and vowed to plant one if I got the chance to move to California. Fortunately, I found out very soon that, while the plantings were made on purpose, they were a mistake and needed to be removed due to their invasive nature.
While they were ‘recruited' from Europe and had what seemed like a perfect resumé (fast growth, lovely yellow flowers, adaptability to poor infertile soil and disease and insect-resistance), they didn't play well with others, a fatal flaw. In California, they were aggressive and crowded out native plantings. Fires only exacerbated the situation. After the 2003 burns, the Spanish Broom populations exploded, obliterating any remaining natives and taking an even larger area hostage. In summer 2010, the San Bernardino National Forest removed the plants in a costly but necessary $500,000 project under a partnership with the American Recovery and Reinvestment Act. Constant monitoring continues in the San Bernardino Mountains and other areas of the state to prevent its reestablishment which is challenging due to its ability to quickly resprout, seed longevity, and effective dispersal. It has definitely earned its ‘noxious weed' label!
This is just one example of the problems posed by invasive plants. In effect, they grow too well! They outcompete desirable plants in our gardens, lawns, and other urban and natural areas for water, nutrients, and space. They also shade sun-requiring plants. Threatened and endangered plant species and other California native plants are particularly vulnerable to their encroachment. (In most cases, invasive plants are non-native species.) Interestingly, our beloved state flower, the California poppy, is an invasive plant in New Zealand, Hawaii and other locations outside of California.
As urban gardeners, we can all greatly reduce the impact of the encroachment of invasive plants in our urban environments. Please don't plant invasive sane remove plantings on your property to stop their spread. Below are some great resources to learn more about invasive plants and find viable replacements:
California Invasive Plant Council: https://www.cal-ipc.org/
Don't Plant a Pest: https://www.cal-ipc.org/solutions/prevention/landscaping/dpp/
Invasive Plants of Southern California:https://www.cal-ipc.org/solutions/prevention/landscaping/dpp/?region=socal
Most trees in California need supplemental irrigation above and beyond what Mother Nature supplies naturally. Even drought-resistant species need regular watering through their first growing season due to their shallow roots. Once trees become established, it's important to water less often but more deeply to encourage deep rooting and structural balance above and below ground. Both under and overwatering can lead to unhealthy trees and even death if the situation is not corrected. Trees receiving too little or too much water exhibit similar symptoms since, in both cases, water is not available to the plant. Trees initially wilt, grow slowly, and develop yellow leaves. Over time, growth stops and leaves become brown and drop. Overwatered trees often develop lower crown and root rot from one or more disease-forming pathogens.
Knowing what type of soil you have (soil texture) is as important as knowing the water needs of your trees. Use the ‘feel test' (pictured below) to find out how much water your soil holds and how often to water. Heavier clay-based soils hold water longer and drain more slowly than sandier soils that need to be watered more often for shorter periods of time.
Trees should not be watered on the same irrigation system used for lawns and groundcovers. Soaker hoses and drip systems allow trees to be watered less often but for longer periods of time than your lawn or groundcover. Avoid applying water too close to the trunk. Instead water half-way between the trunk and the dripline of the tree and outward. If you use a garden hose, apply the water on the lowest volume possible slowly, moving the hose every few hours to each of four quadrants around the tree.
Applying a 3-4 inch layer of mulch around the tree can reduce soil evaporation. Use only non-flammable mulches in fire-prone areas within five feet from the house and non-contiguous for the first 30' away from the house. In all cases keep mulch a few inches away from tree trunks to keep the trunks dry.
Tip: Before planting a tree, make sure there is adequate drainage. Dig a hole where you want to plant it (the same depth of the pot, which is about one foot) and fill the hole with water. Let it completely drain and refill it. Measure the time it takes to drain one inch using a ruler. If it does not drain more than one inch an hour it is not a good location for your tree. Avoid adding compost or soil amendments to try to correct the problem since tree roots will likely grow in circles, staying within the confines of the amended hole rather than growing outward the confines of the amended hole rather than growing outward.
Email a trained University of California Cooperative Extension Master Gardener Volunteer for Help With Your Plant Problems
Unlock the Door to One of the Best Kept Secrets in Southern California!
Did you know that University of California Cooperative Extension has trained Master Gardener volunteers ready to answer your home gardening and landscaping questions throughout the greater Los Angeles area?
Email the Master Gardener helpline in the county in which you reside for the most accurate information since climates and conditions vary across the southland:
Los Angeles County: Email: email@example.com
San Bernardino County: Email: firstname.lastname@example.org
Riverside County: Email: email@example.com
Orange County: Email: firstname.lastname@example.org
Visit http://mg.ucanr.edu for links to other Master Gardener helplines in over 50 California counties!
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