We hope you can join UCCE Stanislaus County Master Gardeners Rho Yare and Ted Hawkins for our Zoom Warm Season Vegetable Gardening class on Tuesday, February 22, 2022 from 6:00-7:30 p.m.

Now is the time to start thinking about which delicious vegetables you want to grow in your garden. Ted and Rho will go over all the possibilities with you in this class.

Spring Vegetables

These vegetables don't mind the cold and can be planted from seed in February. They may grow slowly, but as weather warms they will grow more quickly. Lettuce, Swiss Chard, arugula, mustard greens, and other leafy greens do well. Radishes, beets, carrots, turnips, and happy during this time as well. However, by late spring/early summer, many of these plants can't take the heat and may “bolt,” sending up flower stalks that the bees enjoy.

Summer Vegetables

You can plant these vegetables from seed or transplant in late March. They prefer warm weather and may “sulk” and grow very slowly if you plant them too early. These vegetables include melons, squash, winter squash, corn, tomatoes, and cucumbers.

Hope to “see” you there!

We hope you will join us online for an evening about how to have a successful vegetable garden. If you are a veteran gardener and would like to share your favorite varieties and successes, we hope you will join us and post your favorite vegetables, varieties and other tips in the chat.

Where*: On Zoom. You will receive a link the morning of the class. 
When: Tuesday, February 22, 2022 6:00-7:30 p.m.
Cost: Free
Register at: http://ucanr.edu/spring/veg/2022
Instructors: Master Gardeners Rho Yare and Ted Hawkins 

 

It's been a buggy spring and summer in my new garden, where I've encountered varieties of scale, aphids and flies I hadn't experienced before. About 18 months ago we moved to a new house in a new neighborhood.  With some exceptions, the general goal for our new, smaller garden was to plant drought-tolerant, pollinator-friendly plants, use California natives whenever possible, and encourage beneficial insects.    

Aphids

This spring I planted milkweed seeds obtained from the La Loma Native Garden in Modesto. In May, I discovered the now 6-inch-tall plants were covered from top to bottom with orange-yellow aphids! I learned they are called oleander aphids which are a common pest of milkweed. The leaves of the milkweed looked as if they had white spots all over them.

According to UC Integrated Pest Management (UC IPM), aphids are small, soft pear-shaped bodied insects with long legs and antennae, with slender mouthparts used to pierce stems, leaves and other tender plant parts to suck out plant fluids. The site recommends first attempting to control aphids by washing them off with a gentle stream of water. I did this over several mornings and evenings, with my hose set on fine spray, washing both the top and underside of the leaves. After about a week, I still had quite a few aphids, so I sprayed an insecticidal soap, making sure I covered both the top and bottom of leaves. Aphids produce many offspring, so they required an additional treatment. 

Scale Insects

I brought with me from the old house three pots of cyclamen plants given to me by former students.  These plants were the source of my first insect attack during the spring, which was soft scale.  I've had these plants for 15-20 years have never had a bug problem.  One pot was particularly hard hit with leaf tips appearing browned and wilted, often dropping off.  A sticky honeydew also appeared. Unlike hard scale, which I've experienced with olive trees, where the insect is underneath an armored cover and do not produce honeydew, the soft scale surface is the actual body wall of the insect and cannot be removed.  

Soft scale is a sucking insect, appearing as tiny dots on the leaves or stems of a plant. They can grow up to ¼ inch long and have a smooth, cottony or waxy surface. They feed on the sap of the plant and excrete sticky honeydew, which can attract ants.  Mine were brownish-yellow with a waxy color, usually appearing on the underside of the leaves. 

I removed badly damaged leaves, checked undersides of the leaves for the scale and scraped off any scale I found using a wet Q-tip.  I also checked my other two plants and occasionally found a scale or two on them, scraping them off also.  I repotted the infested plant with potting mix. Over time I was able to completely get rid of the soft scale.

Whiteflies

My final insect encounter was with whiteflies. I've been planting bulbs the past few years, planting dahlias for the first time this spring, which started to bloom in June. The whiteflies showed up in July, particularly infesting the two large white dinner-plate dahlias. The leaves on the plant became mottled yellow. Another sap-sucking insect, whiteflies are not true flies, but are related to aphids, scales, and mealybugs. Adults are tiny insects with a white wax covering on their wings and body. I spent a week trying to wash the whiteflies off with a heavy mist spray of water both on the top and bottom of leaves twice a day, but, it didn't manage them well enough. I switched to spraying on a weekly basis with an insecticidal soap, thoroughly covering both the top and bottoms of the leaves, which has reduced the infestation to a manageable level. Since these dahlias are annuals, not being able to completely eliminate the whiteflies is acceptable in my view. 

 My Buggy Summer Summary

It has been an educational summer learning about these insect pests and dealing with their infestations. I'm gratified I've been able to manage them using less toxic pesticides that are less harmful to beneficial insects and the environment. You can learn more about less toxic pesticides such as insecticidal soaps and oils by visiting the UC IPM website or by watching this video. 

Denise is a UCCE Stanislaus County Master Gardener.

Did you know that plants can suffer sunburn injury just like people? Sunburning of plants is actually a common and serious problem in the San Joaquin Valley, especially after a few days with temperatures over 100° F.

Sunburn is damage to leaves and other plant parts caused by a combination of too much light and heat and insufficient moisture. The first symptom of this problem may be leaves that appear dull or wilted. A yellow or brown “burned” area develops on the leaves, which then dies beginning in areas between the veins. 

The best way to avoid sunburn is to choose plants that are adapted to the planting site. Trying to grow shade-loving plants in full sun is asking for sunburn problems. But even sun-loving plants will suffer sunburning of leaves if the plants are growing in dry soil. You need to provide your plants adequate irrigation water to prevent most sunburning problems.  If you notice the symptoms early enough, you may be able to restore the color to sunburned leaves before they killed.

Sunscald, also sometimes called sunburn, is damage to tree or shrub bark caused by hot sunshine. Sunscalded bark becomes cracked and sunken, and is susceptible to attack by wood-boring insects and wood-rotting fungi. In fact, I almost always find evidence of flatheaded borer injury in trees that have sunscalded bark. Sunscalded trunks and limbs can develop cankers, become girdled, and die.

Sunscald often occurs on young woody plants. Their bark is thin and may not tolerate exposure to direct sun because they were grown in nurseries where their trunks were shaded. Older trees can be damaged if you expose branches to the hot sun by pruning heavily, especially during the summer months. Removing taller trees that provided shade, or adding pavement or buildings that reflect light onto plants can also lead to sunscald. Even in well-watered soil, sunscald may injure bark if plant roots are unable to absorb enough moisture when it's hot.   

You can prevent sunscald through proper planting and pruning. Prune newly planted landscape trees very little or not at all. Leaves not only shade the bark, but manufacture foods necessary for root growth. If there is no foliage growing along the trunk of a newly planted tree, paint the trunk with white interior latex paint, diluted 50 percent with water. Old bark that has been recently exposed to the sun by pruning or limb breakage can also be painted white.  Wood chips and other organic mulches can reduce reflected heat and light, thereby reducing the danger of sunscald.

Each tree and shrub that you plant is adapted to certain amounts of light, depending on species and previous growing conditions. Plant growth can be retarded by too much or too little light. Too little light causes pale foliage and elongated, spindly shoots. Too much light can cause leaves to discolor.  For example, the leaves of camellia plants, which are adapted to partial shade, take on a yellowish tinge when exposed to too much light. The typical leaf color returns when plants receive normal light, but a long period of the wrong light intensity will cause plants to become susceptible to other problems and possibly die. 

As always, it's important to plant species that are well adapted to the amount of light available in your garden. Also, avoid changing the environment in any way that significantly changes the amount of light your established plants are receiving.

Ed Perry is the emeritus Environmental Horticultural Advisor for University of California Cooperative Extension (UCCE) in Stanislaus County where he worked for over 30 years.