- Author: Ann Edahl
First, take care of yourself.
Especially when there is an excessive heat warning, plan any outside chores for the morning, when the temperatures are cooler.
Follow these other steps to prevent heat illness:
- Drink plenty of fluids, such as water and sports drinks. During hot weather, plan to have at least one quart of water available per person per hour of the outdoor activity. Avoid caffeinated drinks.
- Limit your time outdoors.
- Work in the shade when possible.
- Wear a summer hat with a brim and loose-fitting, light-colored, and lightweight clothing like cotton.
- Wear sunscreen (follow this tip whenever you're out in the sun).
- Schedule vigorous activities during the coolest portions of the day and take frequent breaks on hot days.
- If you are feeling symptoms of heat illness, take a rest period in a shaded area. Monitor others around you for symptoms as well.
- Do not overdo! Your weeds will still be there when it cools down a bit.
Next, take care of your plants.
During heat waves, our number-one gardening goal is to keep our plants alive. Plants are sensitive to soil temperature and air temperature, and both can stress them out. You will often see slowing of plant growth or even dropping of flowers during heat waves. For example, many vegetable plants stop flowering above about 90 degrees. Not all is lost, though. If you can get them through the heat wave, they should start producing again when the temps go down.
Plants cool themselves through evaporation, through the pores on their leaves. Generally speaking, the higher the temperature, the greater the water loss. One sign of this is drooping and wilted leaves. In addition, excessive exposure to sunlight can cause sunburn on leaves and stems. Sunburned leaves will be discolored and may turn brown and crispy around the edges. Plants that are highly stressed can also become more vulnerable to insect damage.
Our goal is to minimize the stress brought on by the heat and to avoid doing anything that will stress our plants even more. Here are some dos and don'ts to help mitigate damage to your plants during a heat wave.
DO
- Water your plants thoroughly in the morning if extreme heat is expected. This will help plants cope with the heat. Plants in small pots may even need to be watered twice a day. Check the soil moisture first.
- Water trees deeply and less frequently (that's right, less). The key is “deeply.” This encourages deep roots. Frequent, short periods of watering mean that the roots remain shallow.
- Use a shade cloth (even a bed sheet can work) to shade plants from direct sun and lower the air temperature around the plant.
- Harvest ripening fruit. This can help plants conserve their energy.
- Pay close attention to newly planted plants. They may need more TLC.
- Check on plants that are right next to a walkway or patio. The radiant heat from material like pavers or concrete may cause those plants to show signs of water stress first.
- Mulch, mulch, mulch! A good layer (3 to 4 inches) of mulch, such as compost or wood chips, will prevent the soil around the plant from heating up excessively and will also reduce the amount of water loss. Make sure the mulch is not directly up against the plant, as that can encourage disease.
DON'T
- Do not water midday.
- Do not prune - this will send the plant's energy toward the wound. (Pruning dead branches, especially those that may be a hazard, is fine.)
- Do not fertilize - we don't want to encourage new growth during this period.
- Do not plant or transplant during the heat of summer. It's best to wait until fall for any new planting.
Read more:
Melissa G. Womack. Hot Weather Tips for the Summer Garden. University of California Agriculture and Natural Resources.
University of California Marin Master Gardeners. Heat: Plant Stress in High Temperatures.
- Author: Kathy Keatley Garvey
In images, text, and analogies.
“Just like in a honey bee colony, it takes a team to win an award," he said, and graciously proceeded to thank all those who made it possible. Family, friends, students, postdoctoral fellows, colleagues, staff and more. Or, as he said "work performed by the cast of thousands deserve the distinguished research award."
Leal, former professor and chair of the Department of Entomology (now the Department of Entomology and Nematology) joined the Department of Molecular and Cellular Biology faculty in 2013. He is first UC Davis faculty member to win Academic Senate's trifecta of coveted awards: Distinguished Teaching Award for Undergraduate Teaching (2020), Distinguished Scholarly Public Service Award (2022) and now, the Faculty Distinguished Research Award.
A week before the seminar, Leal was elected to the National Academy of Sciences.
“Dr. Leal is an internationally recognized entomologist and a world leader in his field for his groundbreaking and transformative research in insect olfaction and chemical ecology,” said UC Davis distinguished professor Bruce Hammock, who nominated Leal for the Faculty Distinguished Research Award.
Leal credits Hammock, a 25-year friend and colleague, as instrumental in “luring” him from his tenured position in the Ministry of Agriculture, Forestry, and Fisheries, Japan, to the Department of Entomology (now the Department of Entomology and Nematology) in 2000. A native of Brazil, Leal received his Ph.D. in applied biochemistry from the University of Tsukuba, Japan, with subsequent postdoctoral training in entomology and chemical ecology at the National Institute of Sericultural and Entomological Science and Cornell University, respectively.
In his letter of nomination, Hammock pointed out "I especially applaud him for elucidating the mode of action of the insect repellent DEET, developed in 1946 and known as ‘the gold standard of repellents.' Its mode of action remained an enigma for six decades until Walter's discovery. In researching the neurons in mosquito antennae sensitive to DEET, he isolated the first DEET-sensitive odorant receptor, paving the way for the development of better repellents.”
Leal's analogy of bees working together to succeed, just like what occurs in a successful lab, is spot on. The worker bees inside the hive perform specific duties: nurse maids, nannies, royal attendants, builders, architects, foragers, dancers, honey tenders, pollen packers, propolis or "glue" specialists, air conditioning and heating technicians, guards, and undertakers.
As an aside, Leal mentioned that one research project in his lab involved his daughter Helena, honey bees and her shampoo. “Helena always said the bees were bothering her and then when we collected the volatiles from her, we noticed that there was a contaminant, isoamyl acetate,” Leal told the crowd. “To make a long story short, isoamyl acetate is a chemical that elicits a very aggressive behavior. It's called a sting pheromone known from the early 1960s, and we figured out that that chemical was coming from a shampoo that she was using at that time--the so-called Aussie. So, she stopped using that shampoo and there was no problem with the bees anymore.”
Read more about his lecture here and watch his lecture at https://youtu.be/HkfhsYQE5bI.
- Author: Peggy Smith
As the summer heat creeps up on us once again, we think about how to support our gardens to keep them growing and healthy with careful watering through our long hot days. Our plants and trees are not the only components of our gardens that need the support of water. One of the identified sustainable practices for a garden is the provision of water resources. A quiet spot to sit with a cup of a favorite beverage near a water source in your garden can give a view of garden critters as they stop for a visit to bathe or drink. A healthy garden has lots of movement within it as birds, bees and insects visit the plants that not only delight us but give them sustenance, shelter, and food. A steady water source will draw bees, birds, insects, and butterflies to the garden.
There are many ways to provide water resources from the simple to the more costly and complex.
1) A very simple arrangement that will provide for both bees and birds is a plant drip tray. Take a drip tray and place some stones in it, place it in a shaded area.
2) A variety of hanging water source arrangements are available and they are great for attracting birds to the garden.
3) A moving water source can provide water for birds and entertainment for you as the birds come in and go through their drinking and bathing routines.
4) If you have the room a pond is also an excellent water supply with the added benefit of providing support for insects such as dragonflies and damselflies.
If you install a pond Mosquito Vector Control will provide small fish to take care of any mosquito larvae. https://www.fightthebite.net/services/request-service/
https://mywaterquality.ca.gov/eco_health/wetlands/images/d_delta_changes.jpg
With the disappearance of California wetlands beneficial insects such as dragonflies and damselflies have severely reduced habitat. Dragonflies and damselflies will be attracted to a pond environment. “The female Dragonflies and Damselflies lay their eggs in the water. The Dragonfly lays its eggs directly in the water, while the Damselfly inserts its eggs in underwater vegetation.” The eggs hatch within a few days and the larvae grow quickly. Each larva molts 8 to 16 times during its growth. https://sacsplash.org/learning-resource/dragonflies-and-damselflies/#:~:text=Life%20Cycle%3A,16%20times%20during%20its%20growth. Dragonfly larvae are a preferred food for small fish, so small rock piles, or tight brush piles will give them shelter. Damsel flies will eat flies, mosquitoes, and other tiny insects.
Butterflies need moisture but are unable to land on water, a patch of muddy soil is the best place for a butterfly to access water so if the ground around your drip tray or fountain is a little muddy that is a perfect place for a butterfly to sip.
Birds bathe in a water source as part of maintenance to keep feathers working well. Birds will also flock to the spray of a stationary sprinkler and perch and bathe. https://youtu.be/2hTc9vC1rZc
As with so many things balance is the key, provide water sources for our co-habitating garden critters but make sure there is not stale stagnant water that will encourage mosquito breeding.
Build it and they will come for your garden's benefit also for fun and frolic!
- Author: Karen Metz
I've enjoyed visiting the UC Davis Arboretum many times over the years. Because there is so much to see I've usually focused on one area at a time. In April, I came with a group that had never seen the Arboretum before. Because of health and time constraints, our visit was limited in scope, so I chose the Environmental Gateway Loop as it seemed to pack in many gardens in a small area.
The Arboretum All-Stars planted next to the Teaching Nursery were a beautiful introduction to our day. They were bursting with flowers that were being visited by butterflies, hummingbirds and many species of bees. It was truly a pollinator's paradise. Arboretum All-Stars are plants that haveproven themselves through Arboretum testing. They look good most, if not all, of the year, are hardy, and low maintenance. Most are drought tolerant and attractive to beneficial wildlife.
We visited the Ruth Risdon Storer Garden which showcased lovely lush plantings chosen to tolerate our hot dry summers and wet winters. It was so peaceful and filled with a myriad of textures, colors, and fragrances.
Our next stop was the Moon Garden. The group was totally enchanted with this area. They loved the concept of grouping white, silvery plantings together so the plants would truly glow in the light of the moon. These groupings also included plants that release their strongest fragrance at night which would enhance thenighttime experience even further. Even in the daytime this was a nice spot to sit, rest, andrehydrate.
I had never been to the Peter J Shields Oak Grove before. I enjoyed exploring this shady spot with so many different kinds of Oak species from different parts of the world. The variety in the shape of the leaves was amazing. The grove was accentuated by colorful ceramic tile bench/walls. These identified the different species, and the animals and insects that made up the oak ecosystem.
Beautiful handmade ceramic tiles were also on display at the Nature's Gallery and on the perimeter walls of the restroom. These were collaborations of Art and Science faculty, students, and volunteers. There were flowers, trees, insects, birds and more. All were beautiful and scientifically correct.
There is so much to see at the Arboretum. There are East Asian, Australian, South American, Mexican, and Mediterranean collections, to name a few. The gardens also change with the seasons and change over the years. If you visit most weekends, the parking is free unless there are special events. During the week, parking is challenging, both finding a spot and using the parking app. Only one of our three carloads was successful in getting the app to open. But the experience and the beauty are worth it.
- Author: Ben A Faber
- Posted by: Gale Perez
Rely® 280 Herbicide Available for Use in California Avocado Groves
The California Department of Pesticide Regulation (DPR) has approved the herbicide Rely® 280 (glufosinate-ammonium) for use in avocado groves in California. Rely® 280 is a post-emergence broad-spectrum herbicide for use against broadleaf and grassy weeds. Glufosinate-ammonium is an excellent alternative to glyphosate, especially for those weeds that have developed glyphosate resistance.
The California Avocado Commission provided funding for Dr. Peggy Mauk, extension professor for subtropical horticulture at the University of California, Riverside, to conduct efficacy trials with glufosinate-ammonium and the IR-4 program provided funding for the required phytotoxicity (crop safety) trials. “Glufosinate-ammonium is an effective broad-spectrum herbicide,” said Mauk. “The weed that is the biggest problem here in Riverside is mare's tail or hairy fleabane (Erigeron bonariensis). Glufosinate will kill it depending on the application timing and size of the plants. Treating for weeds is also going to be seasonal… the spring is usually worse because spring rains bring a lot of weeds, especially this past year.”
Dr. Mauk's phytotoxicity trials found minimal damage, assuming sound application practices are followed. “Spray applications should not be made when there is a breeze,” Mauk emphasized. “If the wind carries the herbicide onto the plants, there can be some leaf discoloration. The discoloration appears as occasional purple spots on the leaves. There is not widespread damage. We also never saw any discoloration on the avocado fruit.”
General questions about this registration can be directed to CAC's Research Director Dr. Tim Spann at tim@spannag.com or (423) 609-3451. For specific questions regarding the use of Rely® 280, growers should contact their Pest Control Advisor.
Original source: Topics in Subtropics blog | May 31, 2024
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