- Author: Bonita Malone, UC Master Gardener of Butte County
Once again, we are experiencing a summer of devastating fires, with repercussions that will last decades or even longer. One of the lesser-known ways in which wildfires wreak havoc is the fact that they create ideal conditions for a particular pest, Melanophila acuminata, the black fire beetle. Also known as fire chasers or fire bugs, these beetles are often the very first to arrive at the scene of a conflagration. By using pheromones, chemical signals, and auditory cues, and monitoring temperature and humidity, Melanophila acuminata will fly over eighty miles to a freshly burned forest. Once there, they meet up, mate, and lay eggs, thriving in places most living creatures avoid.
Once they have arrived at the scene of a fire, Melanophila acuminata use sucking mouthparts to ingest tree and plant fluids. Chemical cues from burned vegetation determine the optimum time and place for egg laying. Strong social bonding guides their nesting behavior, provides protection from enemies, aids in finding food, and helps them rear their young.
The eggs, laid under the burned bark of trees, primarily conifers, cannot survive the repelling chemical defenses of healthy trees. Indeed, the eggs are sometimes laid in wood that is still smoldering. To ensure the survival of the young, the parent beetle secretes a nutritious meal made from microorganisms, fungus, aphids, scale insects and occasionally animal flesh. Parents groom and guard the offspring to support a healthy brood.
In short, Melanophila acuminata are complex, innovative creatures. But we hope they are not causing more trouble (and pain) for our much-appreciated firefighters.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
Photo Credit for Melanophila acuminata by AG Prof. Schmitz
We have endured multiple years of drought, and are probably in store for more. For many of us, it makes sense to replace all or part of our lawn area with less water-intensive plantings.
Step One: observe and plan. What existing trees and plants do you want to keep or remove? What are the sun and shade patterns within your yard? What types of grass grow in your lawn? Do you want any additional amenities, such as paving or a shade structure? How will you irrigate your new plants?
Step Two: kill your lawn. Homeowners can use two eco-friendly methods to kill their lawns: Solarizing or Sheet Mulching. For detailed instructions on solarizing, see UC IPM Pestnote on solarization. For instructions on sheet mulching, see our Real Dirt blog post on Sheet Composting.
Sheet mulching kills weeds by starving them of light. It takes 6 to 10 months and can be started any time of the year as long as at least three months of growing season are included. Sheet mulching works in sun or shade, and is effective on all grasses, including Bermuda grass, and many annual and perennial weeds. It is left in place permanently; over time, the dead lawn, sheeting, and mulch will break down into soil-enriching compost. Sheet mulching should be placed before new plants are installed if being used alone to kill lawn or weeds. It can be placed after plants are installed if solarizing has been completed first. New hardscape and irrigation should be installed before commencing solarizing or sheet mulching.
Step Three: replant. Whichever method you choose to kill your lawn, time it so that you are ready to replant in the fall, winter, or early spring. The cool temperatures and moist soils of our wet season allow drought tolerant plants to develop the healthy roots they need to thrive with little water during the heat of summer. Taking time to thoroughly kill the grass and waiting until the climate conditions are suitable for new plants will ensure the long-term success of a lawn replacement project.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
A new season of Master Gardener Workshops is about to start! The series begins September 9th with a session on Neighborhood Habitat Certification, and concludes on December 3rd with a timely workshop on Perennial Vegetable Gardening. In all, this Fall Series totals 14 workshops, including three new topics. There is something here for every type of gardener and every size of home garden, whether you maintain a balcony of plants in containers or produce fruit and vegetables on a large plot for your family, friends and neighbors. For full descriptions of all the workshops and to register, visit our website,
In the months to come, the foundational skills of creating soil-enriching compost; propagating plants through cuttings and divisions; and preparing the garden for winter will be covered. If you are interested in learning fundamental principles of landscape design you can employ in your own garden, our new two-part series on that topic may be just what you've been waiting for.
A new workshop on cultivating perennial vegetables offers a wealth of possibilities for planting vegetables that come back every year, saving labor and introducing new varieties to consider for extra interest in the vegetable garden.
If you are planning to convert all or some of your lawn area to a low-water landscape alive with native plants and humming with beneficial pollinators, our workshop on How to Remove Your Lawn will provide the valuable information you need for this process, from methods of lawn removal through the eventual planting of low water and native plants.
Critters commonly found in our local gardens feature prominently in this Fall Workshop Series, from beneficial visitors (Native Bees, Bats) to unwelcome intruders (Gophers, Moles, and Voles). Learn how to support pollinators and other native wildlife by making your own yard count in the effort to conserve water resources and rebuild local wildlife corridors in our workshop led by the coordinator of Altacal Audubon's Certified Neighborhood Habitat Program.
For the other side of the coin (those unwelcome intruders) our workshop on the basics of Integrated Pest Management focuses on solving pest problems while minimizing risks to people and the environment.
Most of the workshops will be held in the outdoor classroom located in the Master Gardener Demonstration Garden or inside Pat's Barn; both are located at the Patrick Ranch (10381 Midway, between Chico and Durham). The workshops on neighborhood habitat certification and native bees will be will be held in Paradise, at the Terry Ash Center on Skyway; and the Garden Guide workshop will be held at the Plant Barn Nursery on Entler Avenue in Chico. All of the workshops will take place in the morning or early afternoon.
The following is a list of workshop topics and dates. All workshops are free, but they do require advance registration. For full workshop descriptions and to register, visit our website.
Neighborhood Habitat Certification (Monday 9/9). Learn how to make your own yard part of a larger movement to conserve valuable water resources and rebuild much-needed wildlife corridors.
Propagation (Saturday 9/21). Come to learn when and how to propagate woody perennials and divide plants; leave this workshop with plant cuttings from our Demonstration Garden to start at home.
Irrigation (Tuesday 9/24). Drip irrigation is arguably the most efficient method of providing water to trees, crops, gardens, and landscapes. This workshop provides an overview of different options available for drip irrigation systems and covers how to install, inspect, troubleshoot, and repair them.
How to Remove Your Lawn (Thursday 9/26). Learn the steps of killing lawn through sheet mulching or soil solarization, and the process of replanting an area with low water and native plants. A walk through our Demonstration Garden will provide plenty of inspiration.
Gophers, Moles, and Voles (Wednesday 10/9). Learn how to deal with these little monsters that plague our yards; this workshop will include a demonstration on how to set a gopher trap.
Integrated Pest Management (Tuesday 10/15). In this interactive class learn the basics of Integrated Pest Management (IPM) so you can solve your pest problems while minimizing risks to people and the environment.
It's a Wrap! Autumn Garden Cleanup, Winter Prep and Preservation (Saturday 10/19). This workshop/discussion delves into some essential steps to ensure that next year's garden is even more successful.
Composting (Friday 10/25). Learn to make wonderful soil-enriching compost from leaves, garden waste, and kitchen scraps. This workshop covers the different ways to create compost, using techniques that range from simple to complex. Knowing the choices can help you decide which style best fits your own resources and needs.
How to Use Our Garden Guide (Saturday 10/26). Join us to explore how to us our Butte County Garden Guide and Three-Year Journal to find the best times to perform seasonal and weekly garden tasks, as well as useful information on plants, climate, and soil for our region. An integral part of this workshop is using the Garden Guide to record lessons learned and keep track of useful plant and weather information for your garden over the years.
Landscape Design (Thursday 11/7 and Thursday 11/14). Learn the steps that professionals use to develop beautiful, cohesive, lower maintenance planting designs.
Bats (Saturday 11/16). Join our local bat expert, Butte College's Dr. Shahroukh Mistry, to learn everything you've always wanted to know about these fascinating creatures.
Native Bees (Monday 11/18). Did you know that 1600 species of native bees can be found in California? This workshop focuses on a few of them: bumblebees, leaf cutting bees, mason bees, and carpenter bees. Understanding the bees' lifespans and their plant and habitat needs will help you support these valuable pollinators.
DECEMBER
Perennial Vegetable Gardening (Tuesday 12/3). Learn the differences between perennial and annual vegetables, then delve into how to cultivate perennial vegetables. Thirty-five of the best perennial vegetables for our local gardens will be introduced. Why not explore new plants and reduce your gardening labor?
Our Butte County Garden Guide and Three-Year Journal is available in two versions: bound as a book and unbound, ready to add to a loose-leaf binder. It can be found at the Plant Barn Nursery (406 Entler Avenue, Chico), Magnolia Gift and Garden (1367 East Avenue, Chico), and Pat's Barn at the Patrick Ranch Museum (10381 Midway, Durham). They can be ordered online via our website.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
I first heard the term on the local evening news in fall of 2018: Meteorologist Kris Kuyper was talking about hydrophobic soils. This potentially catastrophic natural phenomenon seems counterintuitive: soils which are damaged by the intense heat of fire become water repellent. Their post-fire inability to absorb and filter rainfall can cause problems with erosion and runoff. Adding insult to injury, fire also burns plant roots that can help stabilize the soil, and destroys plant stems and leaves that slow rainfall's contact with the ground surface, allowing more time for percolation into the soil.
According to an article by Douglas Kent (“First Aid for Sonoma County's Fire-Damaged Soil,” Santa Rosa Press Democrat, October 27, 2017), “erosion leaps as high as 200 percent following fires in urbanized areas.” The slopes and vales that comprise the mountain and foothill communities of our region mean that the immediate danger from water repellent soil comes in the form of flash flooding and the flow of debris and mud. Hydrophobia in burn-scarred soils makes them as water repellant as pavement, and the National Weather Service notes that it takes much less rainfall to cause a flash flood in post-fire landscapes. Their rule of thumb is “if you can look uphill from where you are and see a burned area, you are at risk.”
The type of soil and the intensity of the fire determine how deeply hydrophobia penetrates the soil, and how long the condition persists. Paradoxically, the fastest draining soils (light, sandy soils with large pores) are the most prone to post-fire hydrophobicity because they transmit the heat more easily than heavy, dense, clay soils.
The depth of hydrophobic soils can range from one-half inch to three inches, but a depth of about one inch is most common, according to the University of Idaho Cooperative Extension System's Fire No. 5 publication. In some cases, the water repellant soil layer lies a few inches under the soil surface. Although hydrophobic soils can take up to six years to recover their ability to absorb and filtrate rainfall, in most cases this recovery takes about one year. Regardless of the physiology of hydrophobicity, what matters most is how to mitigate its effects.
To hold your ground:
- Clear drainage systems such as culverts, diversion ditches, or narrow swales, of debris. Clogged drains are a primary cause of erosion, even without fire damage.
- Divert water from areas originally designed to sheet runoff to the landscape: instead, redirect the runoff towards your newly cleared drainage systems or, if they exist, towards storm drain systems such as gutters. Use sandbags, diversion ditches, boards stacked on top of one another and staked in place, dry stacked walls, or bales to redirect water flow.
- Minimize foot and equipment traffic on burned landscapes. Such traffic can further compact already damaged soils on flat areas, and can weaken soil bonds and dislodge soil particles on slopes. Develop plans to restore your injured landscape before tramping on it, and keep all traffic to the bare minimum during restoration activities.
- Leave non-toxic debris in place wherever possible. Burnt plant remnants and other garden features can protect the landscape from wind and water erosion, and help protect any seeds and plants that survived the fire.
For more information on dealing with the effects of wildfire on soil, and landscaping with the possibility of fire in mind, see the Fire-Safe Landscape section of the UC Master Gardeners of Butte County website. Among other resources, it contains a link to “The New Normal: Rebuilding Soil After Fire,” a PowerPoint presentation from the UC Master Gardeners of Sonoma County which covers how wildfires affect soil, soil regeneration, and strategies for dealing with toxic soil.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.
How is your garden holding up during our all-too-frequent summer heat waves? Chances are you're seeing scorched leaves, deformed flowers, severe die-back, blistered branches, constant wilting, and even plant loss. Plants are unable to tell us immediately that they're suffering heat stress and sunburn until the damage is evident. As their caretakers, we must observe our backyard environment, heed long-term weather forecasts, and plan for future extreme heat conditions, sometimes many months in advance. Let's look at the causes of heat-related problems and consider some emergency strategies to protect our gardens until the cool autumn weather arrives.
When it's hot and windy and the soil is dry, plants can experience wilt and leaf scorch. Wilt is the earliest and most noticeable signal of heat-related problems. Extreme solar radiation quickens it. Wilt is initially observed when leaves or tender new growth droops, curls, or twists unnaturally. Eventually an entire plant can look limp, a sign of extreme plant stress.
Leaf scorch appears as browned leaf margins that eventually become tissue-paper thin. When whole sections of plants display leaf scorch, it's easy to be misled into thinking that the plant is dying.
There are a few things that can be done immediately to address these heat-related issues when you notice them. A close examination of a specific plant's parts and its surrounding environment is essential. A "bottom-to-top-to-outside" strategy is recommended, meaning that you should address stressed root zones first, then the overheated plants, and finally the superheated environment around and above the plants.
Lack of water is the most likely critical factor in extreme heat-related garden problems. The higher the temperature, with increased sunshine intensity or drying winds, the faster water evaporates, leaves transpire, and the soil dries. Watering not only hydrates roots but cools them as well. Remember this point because the initial water in a hose that has been left in the sun might be scalding hot. While we do not advocate wasting water, in this case it is best to run water through the hose until the water is cool. You should have a few buckets near your faucets to collect the hot water to use later on when it has cooled.
Potted plants require even more attention. Watering them two or more times a day might be necessary. When a potted plant is very stressed, try submerging it in a larger tub filled with cool water to re-wet the soil. Leave it in it until all the bubbling stops, then remove it, let the excess water slowly drain out, and place the plant in the shade.
Remove all weeds around your plants because they are competing for water. In addition to sucking up valuable moisture, weeds steal critical nutrients that your plants require. For example, research shows that calcium helps protect plants from heat stress. Be diligent about removing weeds, grasses, and even seedlings if they're suspected of drawing up too much water from their mother plant.
While you're mulching, check for suckers around trunks or from root shoots. While seasonal pruning should be avoided during high heat spells, removing suckers will reserve water for the original plant. Also, refrain from removing unsightly scorched leaves; portions might still be photosynthesizing and shading stems or new growth at the leaf axils. Remember: don't immediately equate burned leaves to a dead or dying plant. Give it time to recover before removing it.
Now that you've addressed the root and plant issues, move on to the environment around and above the plant. One strategy here is to mist the plant, though this is not a replacement for direct watering. Misting helps reduce air temperature and physically cools leaves. When partnered with shading strategies, mist becomes very helpful in locally reducing extreme heat. It is recommended to mist mid-day to early afternoon, allowing moisture to dry before dusk. Excessive moisture on leaves in the evenings can promote unwanted pests and fungus. Many commercial misting systems have timers and attachments to help you create an overhead system that is best for you and your garden. If you don't want to invest in a misting system, periodic mid-day spraying from a cool garden hose can work wonders to perk up limp, stressed plants. One key consideration about misting is to hand water the stressed plant first to revive it before doing any misting. If you hand mist first, the weight and pressure of the water on a heat-weakened plant might snap off new growth.
It is also important to reduce exposure to the light and heat reflected off buildings, concrete hardscaping, and even gravel walkways. Again, applying shade above plants will reduce the problem, but hanging a dark cloth or tarp on a building's walls or temporarily putting mulch onto concrete or other hardscaping can further reduce issues brought on by reflective heat and light conditions.
Lawns can also suffer during extreme heat events. Watering schedules should be set for early morning, with increased frequency (number of days) and extended watering times. Longer watering periods help grass roots grow deeper into cooler soil, creating increased resilience to extreme heat. A good test to see if a lawn is receiving enough water is observing the grass blades after walking across the lawn: if they bounce back, the lawn is well watered. If they remain bent, the lawn is too dry. Let grass grow longer between mowings (set mower up an inch or more), and never fertilize in the summer months.
Finally, observe the changing areas of light and shade in your garden throughout the year. Note areas that are sunny, those that have morning sun and afternoon shade, those with all-day filtered sunlight, and those with deep shade. Take note of places where reflective light and heat might originate. Determine how wind generally moves through your garden. Take pictures every month from the same vantage points at different times of the day. Your mission is to track the movements of sun and shadow on your garden. Make sure to photograph plants damaged by extreme heat. These aren't beauty shots. You can use this information for future long-term extreme heat mitigation strategies.
Extreme heat conditions are tough on the garden. Incorporating these recommendations shouldn't add too much work to your current garden activities. You'll be happy knowing that you helped your plants survive another summer. And remember to use a good sunscreen and wear a hat when out in the garden yourself.
UC Master Gardeners of Butte County are part of the University of California Cooperative Extension (UCCE) system. To learn more about us and our upcoming events, and for help with gardening in our area visit our website. If you have a gardening question or problem, email the Hotline at mgbutte@ucanr.edu or leave a phone message on our Hotline at 530-552-5812. To speak to a Master Gardener about a gardening issue, or to drop by the MG office during Hotline hours, see the most current information on our Ask Us section of our website.