Spring is here—that time of renewal and joy as we wander our gardens and take stock of what works and what needs a “tune-up.” Sometimes, at this time of year, the number of things to be done in our gardens can seem overwhelming, but attention to just one or two chores per week can lead to both a feeling of control and a beautiful gardening experience.

April Ideas

ONE – First, make the garden and landscape ready for the new season! Check all the sprinklers and drip lines to be sure they are working properly and not wasting water. There is a comprehensive spring tune-up guide for sprinklers in the 2010 April-June Master Gardener newsletter which can be found here.

TWO – April is the time to think about control of the “A” pests: ants, aphids, and abiotic disorders. Manage ants in the landscape and around the foundation of buildings with insecticide baits and sticky barrier pastes. These pastes can also reduce damage caused by insects that ants help protect, such as mealy bugs, certain aphids, and some scale insects. When applying barrier paste to a tree trunk, it is best applied to gauze wrapped lightly but firmly around the trunk, so that the paste is easily removed once it is no longer needed and so it doesn't touch or harm the tree bark. Aphids can be controlled with a strong water spray from your hose. Difficult infestations may need insecticidal oil or soap to reduce the damage aphids can cause. The best solution would be to look for and avoid harm to aphids' natural enemies such as lacewings, lady beetles and syrphids (“hover flies”). Prevent or manage the damage that occurs from aeration deficits, frost, hail, herbicides, wind, and too much or too little water which all weaken plants and contribute to abiotic disorders.

THREE – Now is the time to fertilize lawns and many garden plants. Cane berries, citrus, fruit trees, palms, and heavily flowering shrubs will flourish with slow-release fertilizer products. Maintaining good fertilization can keep your plants vigorous and help prevent pest problems. Lawns will thrive with the application of fertilizer now. Use a balanced slow release or organic fertilizer according to the directions on the package; do not apply more than instructed to avoid polluted runoff. Organic fertilizers react more slowly but will eventually provide a lush result. If crabgrass has been a problem in past years, consider a pre-emergent/fertilizer mix. Help preserve our waterways by avoiding getting granules on hardscape surfaces.

FOUR – This is a great time of year to plant citrus trees if there is a vacant, sunny spot in the landscape. Make a hole about twice the width of the root ball. Build a cone of soil in the center of the hole tall enough so the new plant will be level with the surrounding soil when placed on top of it. Gently remove the plant from its pot. Use fingers to gently uncoil and separate any bunched-up roots. If the root-ball is solid, use a clean knife to score four ½-inch deep cuts around the sides and one on the bottom. Set the roots atop the cone, refill the hole and water thoroughly to eliminate air pockets. The beginning of the root flare on trees should be visible at or above the surrounding soil. Add a 2- to 3-inch layer of mulch around the plant, keeping the mulch several inches away from the trunk.

In May

ONE – Prune a couple of things this month. Winter-flowering shrubs (e.g., camellias) need to be pruned prior to the formation of next year's flower buds. Pruning pine terminals to direct growth in young plants and retard growth in more mature plants should only be done during candling (new shoot growth) during late spring to early summer, so May is usually an opportune time.

TWO – It's May; think mosquitos and mulch. Mosquitos are nobody's friends. To reduce the spread of this pest and the diseases it can bring, eliminate standing water in gutters, drainpipes, flowerpots, old tires, etc. Place Bacillus thuringiensis subspecies israelensis (BT, commonly referred to as “mosquito dunks”) in birdbaths and ponds to selectively kill mosquito larvae. Apply mulch to areas of the garden and under trees where existing mulch is thin, but leave some bare soil for ground-nesting native bees.

THREE – Aerate lawns this month. Lawns that get a lot of heavy fool traffic develop compacted soil, which makes it difficult for water, fertilizer, and oxygen to reach the grass roots. If a screwdriver can't be pushed up to its handle into the turf, it's time to aerate. Use an aerator that either produces a core or a water wash to dig holes; spike aerators just add to soil compaction. If using a machine aerator, be sure to mark and avoid all sprinkler heads. Some machine aerators require a lawn to be moist, but not soggy. Irrigate a day or two before aeration if soil is dry.

FOUR – Fill out vegetable gardens with transplants of tomatoes and peppers. The middle of May is a great time to plant seeds of pumpkins, beans, corn, squash, cucumbers, and melons. For interesting and unusual fall decorations, consider growing pumpkins or winter squash that are not the ordinary jack-o-lantern choice. Beef up a flower garden with a little height. Shorter bedding plants get the front row spot followed by tall, upright bedding plants and finished with some summer-blooming vines grown on a sturdy structure that is set in the garden at the same time planting occurs. It is difficult to add the structure once the plant needs it. As the vine grows, train the shoots to the support with self-gripping Velcro, plant tape, or twist ties. Start with flowers in six packs. Planted in May, these little gems will explode with summer color in a few weeks. If instant color is needed, think about 4-inch pots instead.

June Notes

ONE – Clean up mummies (dried, shriveled fruits) and old fruit and nuts in and under trees to avoid harboring pests, and deter borers by deep-watering trees. Paint the trunk and scaffold branches of young trees with white interior latex paint diluted with an equal amount of water to protect them from sunburn.

TWO – Basil and cilantro planted now will produce fresh herbs all summer. Both annuals do well in pots and love sun and ample water (easy to control if the herbs are in pots). Start basil from seedlings, but sow cilantro seeds directly in the pot; they germinate quickly. Begin harvesting when plants reach 6 inches tall. Other crops to plant from seed in June are cucumbers, green beans, melons, parsnips, pumpkins, and squash.

THREE – Bees are essential pollinators. A variety of flower shapes and colors will attract bees to a garden. Look for flowers and plants that are native to this area for growing ease, adaptation to the local climate, and to serve as an attractant to native bees and honeybees. Planted near or among a vegetable garden, flowers attract bees for pollination and a bountiful harvest.

FOUR – Still have a lawn and wonder just how much water it needs during the hot summer months in the valley? Lawns need about two inches of water per week during the summer heat. To determine lawn sprinklers' output, place several flat-bottomed containers (such as tuna fish cans) around the lawn, turn on the sprinklers for a half hour and then measure the water in the containers. Adjust the sprinkler coverage if needed and reset the amount of time they water according to the results of the timed test. Water lawns and the rest of the landscape early in the day to reduce water wasted due to evaporation and be cognizant of appropriate days to water if applicable. Better yet, start thinking about how to minimize or eliminate the lawn in your landscape to save water in California's dry climate.
Deep-water established plants often enough to prevent wilt and promote deep rooting as temperatures start to rise. Check the soil moisture around roots with a moisture meter probe or by digging down with a trowel. Soaker hoses apply water directly to the soil with minimal evaporation.

Subscribe to our Seasonal Landscape IPM Checklist for Northern San Joaquin Valley. It is delivered straight to your inbox monthly with timely reminders to help prevent or reduce landscape pests and plant problems.

Information for this article was gathered from:

www.ipm.ucdavis.edu
www.sunset.com/garden
www.farmerfred.com
A Valley Gardener's Journal by San Joaquin Master Gardeners
CA Month by Month Gardening by Claire Splan

Question:

I have heard of a disease that has devastated citrus in Florida. Is it in California, and if so, how can we protect the citrus trees in our yard?

Answer:

The disease you are referring to is called Huanglongbing—HLB for short—or citrus greening disease. The HLB disease has decimated the Florida citrus industry, causing billions of dollars in economic damage and thousands of lost jobs. Within four years of its arrival, 60,000 acres of trees were affected with HLB.

The bacterium is spread by the Asian citrus psyllid, Diaphorina citri. There is no cure for the disease; once the tree is infected, it can die in as little as 5 years. The Asian citrus psyllid (ACP) arrived in Southern California from Mexico in 2008. The ACP has now been found in many parts of California, including Southern CA, the Central Coast, the San Joaquin Valley, and the Bay Area. The disease was first found in southern California in 2012. The only way to stop the spread of the disease is to stop the spread of the psyllid. Host plants are all citrus species 

and ornamental plants in the Rutaceae family (e.g. box orange, Indian curry leaf, and orange jasmine).

The best thing a home gardener can do toprevent the spread of HLB is to obey quarantines set in place and to keep a lookout for the insect and report it to the California Department of Food and Agriculture (CDFA) Exotic Pest Hotline at 1-800-491-1899. San Joaquin county is currently under quarantine for ACP. 

Here's what to look for:
The adult psyllid is about the size of an aphid, 1/6 to 1/8 of an inch long. It has mottled brown wings with a clear margin that breaks up the pattern, red eyes, and a pointed rear end. The short antennae have black tips with 

two small, light brown spots on the middle segments. It feeds at a 45-degree angle with its tail end in the air. It lays its yellow or orange, almond-shaped eggs on new plant growth, nestled in the crevices of unfolded leaves. The nymphs are wingless and will molt four times before becoming an adult. They feed on the young soft leaf tissue of the plant. As they feed, they produce a large amount of sugary liquid or “honeydew.” They also produce white, waxy, curly tubules with a bulb on the end to help clear the sugary waste from their bodies. This is unique to the Asian citrus psyllid.

Trees should be inspected monthly and especially during periods of active plant growth or "flushing." Due to the small size of the psyllid, using a magnifying glass or hand lens will make inspection 

easier. Trees infected with HLB produce small, lopsided fruits that are poorly colored with greening on the blossom end, hence the name citrus greening disease. The leaves will have an asymmetrical yellow mottling. Juice and fruit from the infected fruit has a bitter, salty taste.

Encourage beneficial insects that eat the psyllid, including lady beetle adults and larvae, syrphid fly larvae, lacewing larvae, and minute pirate bugs. Some spiders, birds, and other general predators also feed on adult psyllids.

Don't move citrus fruit or plants outside your area. The main way the insect spreads is from people transporting infested plant material. Buy citrus trees only from a reputable, licensed nursery. Double-bag clippings from citrus and other host plants or allow them to dry out thoroughly prior to disposal to avoid moving the psyllid and HLB-infected plant material. 

 

References:
https://www.cdfa.ca.gov
http://californiacitrusthreat.org
http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74155.html

https://ucanr.edu/sites/ACP/
https://cisr.ucr.edu/invasive-species/asian-citrus-psyllid

https://anrcatalog.ucanr.edu/pdf/8205.pdf

 

 

 

 

 

 

Agave: A Worthy Herb

In the back of my mind a song is playing—kind of funny, because it only has one word in the refrain. As a matter of fact, a contestant on AGT performed this song on the show and Simon Cowell (the toughest judge on the show) let him do the complete song without buzzing him off. You have probably heard the song, its melodious saxophone playing up and down the scale to end with a “da da da da dada duhh” as the performer's voice cries out, “Tequila!”

Substitute the word Agave for tequila and we have the same hero in the same song. These two words are nearly synonymous—albeit Agave is the genus of many species of succulents found in the Americas and the West Indies, and tequila is the liquor made in Mexico from blue agave plants raised for the purpose of distilling. The scientific name of this plant is Agave tequilana. Some Tequila producers use various Agave species for distilling their tequila, so it is not allowed to be categorized as 100% blue agave. Tequila is only made in a distinct region in Mexico; if Agave is distilled anywhere else, the product is not tequila—it's just “spirits of agave.”

Now step back and take a deep breath! Agave is quite the herb to incorporate into your gardens, landscapes, or farms. “What?” you ask. That's right, it survives in poor soils (although it does need good drainage), it seldom suffers from nutrient deficiencies, and it is drought tolerant and frost tolerant (for the most part). There are many species of Agave, including A. americana, A. attenuata, A. filifera, A. parryi, A. ovatifolia, and A. victoriae-reginae. They enjoy full sun (six hours or more a day preferred).¹

Some Agaves bloom annually, others bloom once in their lifetimes, which range from as little as seven years up to one hundred years (e.g. the Century Plant). The plant's appearance is certainly a statement-maker, and it grabs the attention of anyone passing—and sometimes grabs your shirttail as well! Most Agaves have sharp spines on the ends of their fleshy leaves, which also typically have sharp serrated edges, and each leaf may show “shadows” of other leaves from where they were formed inside the center growth spike.

There is lots of information on how and why to use Agave, as well as the historic view of this “mystical” plant and its uses. Let me walk you down the historic trail and gain some insight as to why this plant was so important to the indigenous people of the New World and also to the New World explorers.

Long before Christopher Columbus “discovered” the Americas, the native inhabitants of Central America included the Aztecs. Aztec legend has it that an evil goddess of the sky was responsible for the darkness of earth and devoured light to spite them, demanding them to perform human sacrifices in order to gain daylight. Life was grim! The “Feathered Serpent” Quetzalcoatl tired of this awful treatment of his people and decided to ascend into the sky to call the goddess out to a duel. While he didn't find her, he did find her granddaughter, Mayahuel, who was being hidden in the clouds against her will. Mayahuel was a goddess of fertility, and Quetzalcoatl fell in love with her and returned her to earth to live with him. This really annoyed the evil sky goddess, and she came down to earth and killed Mayahuel, breaking Quetzalcoatl's heart. Quetzalcoatl subsequently took revenge and killed the evil goddess.

Quetzalcoatl's loneliness as he cried nightly at Mayahuel's grave saddened the other gods, so much so, they decided to bring a new plant to life at her burial site. The plant had minor hallucinogenic properties to help comfort the soul of Quetzalcoatl when he drank the elixir that came from the plant. The plant, of course, was Agave; that is how the plant came to be, and why tequila is considered the drink of choice for comforting the soul of those who have lost someone dear to their hearts. Plenty of New World inhabitants today console themselves with an Agave supplement when they find themselves heartbroken!

The Agave plant is also known as maguey, and it produces a liquid called pulque—the ancient predecessor to tequila. Pulque was not distilled; the aquamiel (literally “honey water” or sap of the plant) was allowed to ferment naturally, similar to winemaking resulting in pulque.²

In recent years, studies have been conducted to determine the economic viability of growing blue agave as a crop in the United States. A “Tasting Event” last September showcased research on Agave production.³ UCANR and UC-Davis are heavily involved in this research.⁴

While the outside appearance of the Agave plant is somewhat fierce, it has its enemy in the shape of an insect—the yucca weevil—which is equally fierce looking and can inflict deadly damage to the plant. Check out the photo below and follow the reference link for more information on controls. ⁴

Additionally, if any of you Master Gardeners would like to join us at Herb Study meetings, they occur on the fourth Tuesday of each month, 9:30 a.m. to 11:30 a.m. at the Robert J. Cabral Agriculture Center, 2101 Earhart Street, Stockton. Lots to discover out there in the real world—come join us!

¹ UC Master Gardener Program of Sonoma County, August 2019

² From an article by Colleen Graham on Alternative Religions

³ https://ucanr.edu/News/?routeName=newsstory&postnum=54946

⁴ https://ipm.ucanr.edu/PMG/GARDEN/PLANTS/INVERT/yuccaweevil.html

Dive into the fascinating world of horticulture as we demystify the language of gardening, empowering enthusiasts within the knowledge to cultivate thriving gardens. Join us as we explore the rich lexicon that defines the art and science of horticulture.

Aggregate Fruit: noun Botany. A fruit formed by several ovaries in the pistil of a single flower. All these tiny eggs are pollinated and meld together to form a single fruit. Examples include raspberries and blackberries.

Accessory Fruit: noun Botany. A fruit that is derived from the pollinated ovary and other flower parts which expand and ripen around the seeds. They do not split open to disperse the seeds. Examples include strawberries, pears, apples, pomegranates and figs. Think of all of the seeds inside the fruit!

Berry: noun Botany. A true fruit formed directly from the ovary of a flower. (See Horticultural Terms article in the Fall 2023 blog.) Examples include blueberries and bananas!

Fruit development is a complex and varied botanical event that provides nutritious treats for birds and bees and animals of all kinds, but most delightfully to humans. Most of us just call them by their common names: berries of all kinds, apples, and pears. But scientists have been able to analyze the details of fruit procreation and development in ways unimaginable. 

The general public will continue to call fruits by their common names, but now when you find the seeds in a fruit or feel the lumpy exterior of a raspberry you can marvel at the diversity of morphology within the category of “fruit.”