Pests of the Season
Morris Lacey, Master Gardener

Spring is either here or just around the corner, dependent upon your Hardiness Zone (those of you in the foothills still have a little longer to wait). In San Joaquin County, gardeners face the peskiness of our new “normal” warmer weather which wears on our patience and urges us to plant in early February - despite our data-based knowledge which keeps telling us to be prepared for frost as late as March 7 (Zone 9b, Old Farmer's Almanac). I remember my wife and I living in central New York and trying to be patient for May 31 to arrive to get us past the potential last date for frost. Our neighbor warned us our first year there as we began May with temperatures in the 70's. Everything was jumping out of the ground, and that fooled us into believing we had struck the lottery and could plant tomatoes in the garden early and unprotected. We found out different on the last day of the month. You guessed it, a hard freeze - with snow!

FROST can be pesky and, while it is not a “pest” per say, it should be dealt with simply enough by planning and staying the course of your Hardiness Zone recommendations. When in doubt, listen to your neighbors who have lived in the area for years – they should provide sage advice regarding frost and your plantingtimeline.

LAWN DIEBACK - Lawns should be thriving at this time of year, coming off late winter moisture in the form of rain, fog, or dew. Even without said moisture, the ground has yet to give up all the wet of winter as the weather continues to provide cool nights keeping the ground damp below the reach of the short hours of daylight warmth. Invariably, lawns may have a large spot or two of browned-out dying grass which begs the gardener to question “what is causing that?” Good question! But don't jump to conclusions – investigate scientifically and identify the cause.

The reason behind this “pesky” situation may be as simple as dog urine (small circles) or too much water too soon for a season still cool for the type of grass planted or not enough water because the rain expected didn't come! Our recent windy days did pull the humidity out of the upper portion of our yards and grass may be living on short roots from previous seasons of light watering as opposed to long roots from a good soaking. If you don't find any of these options plausible, look for grubs around the roots. If there are less than 6 cutworms or white grubs within one square foot, no treatment necessary. Conduct a soil drench test to identify possible other insect pests which may be causing the dieback. If you do not find insects in significant amounts, do not treat with pesticides. If you do find insects in significant amounts, identify which insect is doing the damage and modify the environment to discourage the insect if possible. As a last resort, choose an insecticide which targets your pest.

In the photo above, the area of lawn die-back exhibits a carpet of dead grass and soil which is damp to the touch with no evidence of insects. A healthy border of shrubs is between the lawn and the front porch of the house. This portion of the lawn has been in shade all winter and a sprinkler system watered the lawn all winter as the owner lost a loved one late last year and is just now getting around to the former tasks of the deceased relative.

APHIDS - Plums are popular home garden fruit trees for our California small yards. Plum trees are productive and come in varieties pleasing most individual tastebuds. Springtime is the best time to pay close attention to the new growth and ensure fruiting success. Like Peaches and Nectarines, Plums may exhibit a “leaf curl”; however, unlike Peach Leaf Curl (caused by a fungus) plum leaf curl is caused by aphids attacking the new growth in copious amounts causing the leaf to roll up into misshapen and dysfunctional leaves which do not benefit the tree. These pesky pests can reduce the productivity of your tree and, if left unchecked, may defoliate branches and limbs placing the health of the tree in jeopardy.

Identify the aphids as the cause of the leaf curl and remove the curled leaves by hand (good method) and squish the aphids or use a good stream of water (better method) to wash off the aphids or use soapy water (best method) to knock them off and “suffocate” the little beasts.

Limit the use of pesticides around these great fruit producing trees unless all else fails! Monitor the trunk of the tree for ants and apply sticky dressing to limit the access of the canopy to the ants (prevention).

Visit http://sjmastergardeners.ucanr.edu/index.cfm or call 800-555-1212 with your questions regarding specific issues you may encounter in the pursuit of gardening enjoyment.
Pest Notes Publication 7404 Aphids, Pest Notes Publication 7476 Lawn Insects
UCANR – U.S. Hardiness Zone Map

Plants of the Season
Lee Miller, Master Gardener

BULBS: Bugle Lily, Watsonia pillansii which is in the Lily family. It is native to South Africa and is grown from a corm much like gladiolus. The flowers rise on spikes from thick sword-like leaves about 18 inches long. Flowers soar almost a foot above the foliage and may be orange, red, pink, coral, white, or yellow. Blooms are 3 inches long and last several weeks, making them an attractive cut flower. Corms are modified roots that act as storage organs, much like bulbs or rhizomes. They will show well in the back of the border. They are easy to grow as long as the soil is well drained. They are normally planted in the fall and flower in spring and summer. You can prepare a bed by adding compost and working it in to a depth of 6 inches and then bury corms 4-5 inches deep and spaced about 12 inches apart. The soil needs to be moderately moist through the growing season. They can be harvested as a cut flower as well as being enjoyed in the landscape. They will need to be divided every few years when the corms get crowded and you can share corms as one of our Master Gardeners recently did with me. Thanks, Linda.

FRUIT TREE: Laroda plum (Prunus salicina) Spring is a good time to get that fruit tree in if you didn't get a bare root planted earlier. The Laroda plum is a great choice in plums because it has a long harvest season beginning in early-July and extending to mid-August or later. This is much longer than the harvest season for the other Japanese type plums like the Santa Rosa which last perhaps 10 days. The Laroda plum has received high overall scores in Dave Wilson Nursery tastings for its sweet, excellent flavor. The skin color is a dark purple and the flesh is amber with streaks of red on the inside. The texture is firm with high sweetness. The color is similar to Santa Rosa, but it is larger and ripens about a month later. It is a mid-season bloomer and requires a pollinizer such as Santa Rosa or Catalina. I never got to enjoy the fruit from the one I planted at my former homestead, but I did take scion wood from that tree and grafted over two flowering plums at my new home. I have been enjoying heavy production of these beauties for 3 years now.

Loropetalum in bloom at my home on Feb. 10.

SHRUB: Chinese fringe flower (Loropetalum chinense) is a shrub that blooms profusely with spidery pink flowers in early spring and more modest repeat blooms later. It is native to woodland regions of the Himalayas, China, and Japan, Flowers are lightly fragrant. It is a relative of witch hazel with fine textured, evergreen foliage and leaves that change color through the season from green to burgundy or purple. Leaves are oval and 1-2.5 inches long. It has a layered branching habit, and the height can be as large as 15 feet and spread can be up to 10 ft. depending on the variety. It does best with 6 hours of sun but can do with light afternoon shade in hot climates like ours. Prefers slightly acid soil but where I live it seems fine with a soil of pH 7. It is easy to grow and requires little maintenance and is good addition to an easy-care landscape. Loropetalum blooms on old wood so best to wait until flowers are finished in spring before pruning which consists mostly of trimming out dead and diseased branches or lightly shape as needed. Moderate watering is advised until it is established. It is drought tolerant once well established. Mulching is good practice. All parts of Loropetalum are non-toxic to pets and children.

Some Good News for Western Monarch Butterflies…maybe
By Susan Mora Loyko, Master Gardener

There was more than turkey to be thankful for last November at the 25th Annual Xerces Society's Western Monarch Thanksgiving Count held in Pacific Grove. After several years of the butterflies' declining numbers, the final count was about 250,000. The 2020 butterfly count marked an all-time low of less than 2,000 Monarchs.

Monarchs living west of the Rocky Mountain overwinter in California along the Mendocino Coast and are known to gather in giant clusters of Eucalyptus, Monterey Pines, and Monterey Cypresses, as far south as Baja.

While scientists, volunteers, and lovers of the Monarchs were thrilled in the increased butterfly numbers, there was also concern the rise could be a fluke. The migratory butterflies had a steady decline for the last several years with populations at more than 95% below those of the 1980s.

The decrease began in 2017, a year of unusual heat at critical times of the year with long periods of temperatures more than 90°, unfavorable to butterfly eggs according to Dr. Chip Taylor, Professor Emeritus of Ecology and Evolutionary Biology, University of Kansas, and Director of Monarch Watch. He said the recent rise in temperatures across the country have been linked with declining butterfly populations, particularly on the West Coast where temperatures have been rising 0.7 degrees per decade since 1975.

Monarchs also have many natural enemies. Predators such as spiders and fire ants kill and eat Monarch eggs and caterpillars. Some birds and wasps feed on the adult butterflies. Monarchs also suffer attacks from parasites, organisms living inside their bodies.

Data from the annual butterfly count, along with monitoring twice during the overwintering season, allows researchers to observe how Monarchs are using overwintering sites: some sites host Monarchs all winter, while others are transitional sites. It's important to note they continue to face threats and require more monitoring to better understand their risks and what conservation efforts are still needed to recover.

Why should we care about the health and future of the Monarch Butterflies and other pollinators? Their flight across the country (along with bees and other small insects) are essential to our ecosystem to pollinate flowers, fruits, and vegetables and ultimately our larger food systems.

Each spring, Monarchs leave overwintering sites and disperse across California first, and eventually migrate to all western states, searching for milkweed plants on which to lay their eggs. It is the only plant Monarch caterpillars can eat to develop into adults.

Several generations are produced throughout the spring, summer, and fall, with each generation spreading further across the landscape. The last generation then migrates all the way back to the overwintering grounds on the Pacific coast in the fall and return to the same groves of trees each year!

Milkweeds (Asclepias spp.) are required important host plants for Monarch caterpillars in their life cycle. The loss of milkweed plants in the Monarch's spring and summer breeding areas across the country is believed to be a significant factor contributing to their reduced numbers in California/Mexico overwintering sites. Agricultural intensification, development of rural lands, mowing, and herbicides to control roadside vegetation also contribute to the milkweed loss.

 

Here are Xerces Society recommendations to help the Monarchs:

• Plant native milkweed in your backyard, workplace, or school. If outside of native milkweed's historic range, Xerces recommends planting fall, winter, and spring blooming nectar sources INSTEAD of milkweed.
• Plant a diversity of native flowers. Monarchs need nectar to provide energy to migrate, breed, and overwinter. Nectar plants can be planted anywhere.
• Support organic and GMO-free agriculture.
  Avoid using pesticides. These may kill butterflies, caterpillars and plants used for nectar or breeding.
• Get involved in community science projects.

Winter is finally here! Leaves have fallen or are in the process of leaving our deciduous plants naked. Sends shivers up my spine!

What's an avid gardener to do? There must be more to life than raking leaves. Growing winter crops help us stay active in the garden with the added benefit of providing vegetables and fruit for our friends and family. Pests are ready to take advantage of our weaknesses should we drop our guard and ignore their signs. Use these simple scientifically proven methods to control the following pests of the season. You may also learn of other pests you encounter this winter and learn how best to deal with them at your local Cooperative Extension via the volunteer Master Gardener program in the form of telephone hotline or website, listed at the bottom of the page.

Black Aphids are a common pest during the late fall / early winter period attacking green onions, garlic, and chives, including society chives (landscape). These aphids suck the life out of the plant while they feast up and down the leaves, reproducing parthenogenically, birthing live offspring along their way. If you catch them early you can prevent damage by washing them off with a firm stream of water. In the cooler weather you may not check your crop daily and may encounter plants covered from top to bottom with black dots as pictured above – these may require at the minimum a soapy water mix or Neem Oil mixture to salvage the crop. Be sure to follow manufacturer's directions when applying Neem Oil products. Aphids may escape and hide in the innermost leaf material surrounding the stem and bulb. If you choose to transplant these affected plants, make sure to leave the aphids behind by submerging the plant in a bucket of soapy water to suffocate the little critters. Peel back as much of the damaged leaves as possible to eliminate their hiding places. For more info, visit the UC IPM Page.

Fungus pests are hiding at this time of year. One such hidden pest waiting to rear its ugliness in the coming spring is Leaf Curl, Taphrina deformans, which typically attacks nectarines and peaches. Since the leaves are all off, now is the time to apply a preventive fungicide treatment. If timed properly, a single fall/winter treatment of copper-based fungicide can prevent leaf curl and shot hole disease! A “2-fer”! 

If your trees showed symptoms last spring, be sure to treat your trees now. Don't wait to see if it disappeared by itself or your pruning removed all the infested areas. It is still there and needs treatment to stop its spread. Your fruit production will improve, and your neighbors will thank you for sharing your bounty. For more information visit the UC IPM page.

 

Do you recognize the plant in the picture? While this “grass” mixes well with commercial sod and can become one with your lawn, it also spreads from its wind-blown seeds and germinates heartily in the winter in our flower or vegetable gardens. Vulpia microstachys is a species of grass known by the common names Small Fescue and Small Six-weeks Grass. Native to western North America, its presence in the flower garden or crowding out your vegetables can relegate it to “pest” status. To manage this pesky grass, simply pull it out by hand or uproot it with a flat or hula hoe and remove it from the area. It can go in the compost pile if you make sure the pile heats up properly to kill off the seeds, lest you plan to spread your compost on the lawn to improve thickness of said lawn in the cooler weather. If it goes to seed before you remove it, you will get another crop with the next rain or watering. Good news – it usually only lives 6 weeks.

 

Visit http://sjmastergardeners.ucanr.edu or call us at 209-953-6112 with your questions regarding specific issues you may encounter in the pursuit of gardening enjoyment.