- Author: Melissa G. Womack
Almost any home gardener will tell you that one of the most versatile and rewarding plants to grow in a summer edible garden is a tomato. In fact, a 2023 study by the National Gardening Association revealed that 86 percent of gardeners grow tomatoes. It is understandable that the tomato plant is a popular home vegetable garden staple, tomatoes offer thousands of different varieties options and flavors. Plus, nothing beats the bursting flavor of a ripe tomato straight from the garden.
When properly cared for, a single tomato plant can produce 10 to 15 pounds (4.5 to 6.8 kg) or more of fruit. As with any gardening journey, sometimes there can be obstacles or challenges to overcome. If tomato yields aren't what was expected, or the fruit is damaged, it could be due to a number of abiotic disorders, diseases or pesky pests.
Abiotic disorders result from non-living causes and are often environmental, for example: unfavorable soil conditions, too much or too little water, extreme temperature, physical or chemical injuries, and other issues that can harm or kill a plant. Using research-based information from UC Agriculture and Natural Resources (UC ANR) publication, Growing Tomatoes in the Home Garden.
Here are five of the most common abiotic disorders of tomatoes and how to address them:
- Sunburn or Sunscald: Yes, just like humans tomatoes can also suffer from sunburns because of overexposure to the sun. Sunburnorsunscald occurs on the side of the fruit exposed to the sun, which turns brown and becomes leathery in texture. Solutions:
- Maintain the plant canopy to produce adequate leaf cover for the fruit.
- Avoid overpruning.
- Provide partial shade during peaks sunlight hours.
- Leaf Roll: You might find that the older leaves on your plant suddenly roll upward and inward, becoming stiff, brittle and tough to the touch. This is typically caused by high light intensity and moist soil, especially in staked and heavily pruned plants. Solutions:
- Choose less-susceptible varieties.
- Maintain even soil moisture.
- Provide partial shade during peaks sunlight hours.
- Blossom End Rot: This condition appears as a water-soaked spot at the blossom end of the fruit, which enlarges and darkens, creating a sunken, leathery appearance. It's more prevalent in sandy soils and is primarily caused by calcium nutrition imbalance and inconsistent water levels. Solutions:
- Maintain even soil moisture.
- Amend planting area with compost to improve water retention.
- Avoid heavy applications of high-nitrogen fertilizer.
- Soils deficient in calcium may be amended with gypsum.
- Fruit Cracks and Catfacing: Rapid growth during high temperatures and excessive soil moisture can lead to circular concentric cracks around the stem end, radial cracks shooting out from the stem, and malformation and cracking at the blossom end, a phenomenon known as ‘catfacing'. Solution:
- Keep soil evenly moist.
- Maintain good leaf cover or provide partial shade during hours of most intense sunlight.
- Mulch around the plant 3 to 7 inches deep to maintain soil moisture and temperature.
- Solar Yellowing and Green Shoulders: This problem is marked by the tomato turning yellow or yellow-orange instead of the normal red color, with the upper part of the fruit stubbornly staying green even though the lower part appears red and ripe. It's a result of high temperatures and intense light. Solutions:
- Maintian plant vigor to produce adequate leaf cover.
- Avoid overpruning.
- Provide partial shade during hours of most intense sunlight.
A variety of insects and pests can cause other damage to tomato plants. Some examples of common pests, include: hornworms, tomato fruitworms, tomato pinworms, stink bugs, white flies, and leafminers. For information about identifying and managing pests in your edible garden visit the UC Integrated Pest Management (UC IPM) website, ipm.ucanr.edu.
Navigating the ups and downs of growing tomatoes might seem daunting, but don't forget, every seasoned gardener has been in your shoes once. We've explored the common abiotic diseases and challenges you might encounter in your tomato-growing journey, and hopefully armed you with solutions to keep these issues at bay.
If you have additional questions or need more help, don't hesitate to reach out to your local UC Master Gardener Program. We have a team of volunteers trained and eager to help you have a bountiful harvest! mg.ucanr.edu/FindUs
Source: Growing Tomatoes in the Home Garden Publication 8159 http://anrcatalog.ucanr.edu/pdf/8159.pdf
The Spotted Lanternfly (SLF) is an invasive pest that poses a great threat to California's agriculture. It was first discovered in the U.S. in Pennsylvania in 2014 and has since taken the east coast by storm, causing damage to many plant species and proving to be difficult to control. Although this pest hasn't been found in California, it is important to keep an eye out to catch an invasion early.
What does the spotted lanternfly look like?
The SLF adult is about 1 inch in length with grayish wings, black spots, and red hind wings. Egg masses are laid in the fall on the east coast and resemble splotches of mud. They are often laid on smooth surfaces like branches, rocks, or outdoor furniture. Early nymphs are very small, wingless, and black with white spots. The last nymphal stage is 1/2 inch long and red with white and black markings.
What damage does the spotted lanternfly cause?
On the east coast, the spotted lanternfly's preferred host is the invasive tree-of-heaven (Ailanthus altissima), but it will also feed heavily on grapes, maples, willows, and birch trees. SLF feeds on plant sap and excretes honeydew, which can cause sooty mold to grow on leaves and fruit. It is known to kill black walnut saplings, tree-of-heaven, and grapevines. However, for most other plants SLF is considered a plant stressor and healthy plants can usually tolerate feeding.
What can you do to help keep the spotted lanternfly out?
Spotted lanternfly is easily transported to new areas as egg masses on firewood, stone, cars, and furniture. Check vehicles and trailers when traveling to areas where SLF has been confirmed. Inspect items purchased or shipped from these areas, and don't move firewood. Familiarize yourself with the various ways that SLF egg masses may appear and report any potential sightings to the CDFA Pest Hotline: 1-800-491-1899.
If you want to learn more, visit the UC IPM Spotted Lanternfly page and consider taking the California Master Gardener Spotted Lantern Fly training module.
- Author: Lauren Snowden
SLF is a destructive invasive insect threatening agricultural and ornamental plants across the United States. Although the pest is not in California at this time, a key to slowing its spread is early detection and rapid response if detected. Through the education of California residents and resource professionals, we can all be part of keeping this invasive pest at bay.
With the assistance of the California Department of Food and Agriculture, UC Academics, and Penn State Extension, the UC Master Gardener Program “Spotted Lanternfly in California” eLearning course was created and is now available to all. Pest information and additional resources are available online.
How to Enroll
Course enrollment is free and accessed through eXtension Campus, you must either have or create a free login to enroll in the course. If you encounter problems or have questions about creating your account, please see the Campus Help Page. The course takes approximately 40 minutes and includes a graded quiz, completion time may vary by user. Learners may stop and restart, or take as many times as needed.
How to Receive a Certificate
To receive a certificate for the “Spotted Lanternfly in California” eLearning course, you must view and complete the module, as well as pass the quiz with a score of 80% or higher. Once you have passed the quiz, you can print a certificate and collect a virtual Spotted Lanternfly eLearning badge.
UC Master Gardeners are eligible for one hour of continuing education for completing the “Spotted Lanternfly in California” eLearning course. It is the volunteers' responsibility to enter their hours in the Volunteer Management System to receive credit.
- Author: Lauren Snowden
It may seem odd to see seventy-five people at a hotel conference center learning about insects and rats on vegetables, but not if you are a UC Master Gardener. The UC Statewide Integrated Pest Management Program (UC IPM) in partnership with the UC Master Gardener Program just wrapped up the Vegetable Pests and Solutions train-the-trainer series. More than 340 UC Master Gardener volunteers from across the state took part in the regional trainings offered in Fresno, Orange, Placer, San Luis Obispo and Sonoma counties.
The advanced UC IPM training offered a hands-on, train-the-trainer experience that increased participants' knowledge of insect pests of vegetables, vegetable plant diseases and disorders, and vertebrate pests of gardens and homes. One of the highlights of the training was Human-Wildlife Interaction Advisor, Niamh Quinn, showing a taxidermy collection of vertebrate pests at the Orange and San Luis Obispo County workshops. Being able to handle and observe the different markings, colors and claws on certain animals makes future identification easier as participants learned the signs to look for when identifying vertebrate pest damage in the vegetable garden.
UC Master Gardener volunteers were lead through exercises that mimic questions commonly received from the public. Some of the questions had a photo, others just a sparse description that volunteers worked together to solve using online IPM resources and materials provided at the training. The exercises were designed to challenge and expose the learner to different types of scenarios and tools they can use in the future.
Outreach and Education
The UC Master Gardener Program's mission is to extend research-based information, by attending advanced trainings such as this, volunteers are even more prepared to contribute to the program's mission. With exposure and practice using new resources and materials training attendees have the tools and knowledge needed to educate the public on vegetable pests and solutions including scripted PowerPoints, activities, handouts, and vegetable pest identification card sets. One attendee reported “As a first year UC Master Gardener, this training helped me become more comfortable and more confident researching answers for pest management questions.”
At the conclusion of the training volunteers convened with their fellow county volunteers to talk about their plans to take new found knowledge back into their communities. Some of the great ideas generated were:
- offer seasonal pest problems workshops
- include a “Need Help Solving Pest Problems?” flier for all events
- add IPM tips to newsletters and social media
- integrate IPM into presentations as appropriate or relevant to topic
- add signage for damaged or diseased plants with IPM solutions in demonstration gardens
- share IPM toolkit at farmers markets and demo garden events
How We are Making a Difference
One portion of the agenda was focused on how the UC Master Gardener community is making a difference. With 6,000+ volunteers serving more than 517,000 Californians per year the impact of the UC Master Gardener volunteer effort is truly amazing. Through statewide program evaluation efforts the impact in sustainable landscaping, food gardening and community well-being is now being analyzed and reported in the programs annual report. Volunteers can see the impact they are having statewide and be proud of being part of a group that social changes they are seeing in their local communities.
As active volunteers and life-long learners UC Master Gardeners are a powerful educational tool and inspiration for others not only in the garden but in the volunteer community. Statewide educational offerings like UC IPM's train-the-trainer series help hone the diagnostics skills while building confidence in the subject matter.
The next statewide training opportunity for UC Master Gardener volunteers will be the 2020 UC Master Gardener Conference, Sept. 28 –Oct. 2, 2020 at the Granlibakken, Tahoe. The conference is the beginning planning stages and taking speaker and topic suggestions, click here to suggest a speaker or topic.
- Author: Donna Navarro Valadez
In the heart of San Mateo County sits a garden gem, The Gardening Education Center, a 5,000 square foot growing space established by the UC Master Gardener Program of San Mateo County. This green garden space was approximately three years in the making, which included fundraising, planning, and actively working the land.
In the spring of 2018, when the site was unveiled, UC Master Gardener volunteers went to work. The plan was to prepare the space for a small (4-5 fruit tree) orchard, three large raised bed planters for seasonal flowers and vegetables, and separate specialty in-ground beds featuring natives, succulents and other drought tolerant plantings.
Prior to the planting, UC Master Gardener volunteers sheet mulched with cardboard and wood chips. This assisted in smothering the invasive groundcover that had taken over the overgrown neglected space.
Unbeknownst to UC Master Gardener volunteers, there was significantly more Bermuda grass than was initially suspected. Bermuda grass seeds can be an aggressive, the grass itself is tough and persistent. Over the next few months the grass eventually crept in and completely took over. Drastic measures were needed to eradicate the pesky weeds so the committed volunteers accepted the challenge and made a plan to eradicate the invasive grass without utilizing chemicals.
The plan of attack included eradicating as much Bermuda grass as possible from the very compacted and dry soil as naturally as possible. They scraped the top few inches of the soil off of the area to get rid of as many rhizomes and stolons of the pernicious Bermuda grass.
They worked tirelessly to remove the Bermuda grass, and prepared the soil for compost tea and cover crop planting. By removing the Bermuda grass it made a huge difference in the look, health and overall maintenance of the garden space.
The following eight cool season cover crops were chosen for the first planting because of these benefits:
In the end, UC Master Gardener volunteers produced a harvest of plenty. They learned the finer points of making compost extract using premier compost and applying it to the soil to introduce microbial life into the soil, attracting beneficial fungi, nematodes and earthworms. Not only were they able to plant diverse cover crops that crowded out the weeds, they were also successful in reaching their goal of treating the 1,600 square foot space of garden soil with no pesticides.
The Gardening Education Center has been open to UC Master Gardener volunteers since last spring, as they work to create the infrastructure to accommodate classes for the public. There are three greenhouses onsite that are currently growing plants for the UC Master Gardener Program of San Mateo and San Francisco Counties.
Compost Class pictured above, front row from left to right: Mark Foulard, Norine Cepernich, Terry Messinger, Maggi Lim, Cathy Vreeberg, Gaye Torjusen, (and standing) Nancy Kruberg, Terry Lyngso, and Steve Maskel. Second row from left ot right: Patty Deering, Linda Dvorak,Kathy Stamm, Kate Sweetman, Carol O'Donnell, John O'Hara, Charlie Akers, Charlene Landreau, Ginny Piazza, Cynthia Nations, Nick Landolfi, Janet Gilmore, Yana Maloney, and behind Yana, John Bassetto (Norine's husband and heavy equipment operator).
Many thanks to this group of volunteers, who have led the efforts and plan for The Gardening Education Center space and whom have spent countless volunteer hours! They have put a lot of thought into making this an excellent learning process for all. We would like to especially recognize Terry Lyngso, whom donated compost, seeds and paving stones to the project.