One of the comments we often hear as Master Gardeners is “My pepper plants grow but I get only a few small peppers or no peppers at all”. After a couple of frustrating years many gardeners stop growing peppers altogether. Peppers are a nutritional powerhouse as well as a rainbow of color, and they deserve a place in the garden. With attention to a few details, you can grow a “peck” of peppers and add a burst of color to your garden and your dinner plate.

While peppers are not hard to grow, they are quirky in a few areas.

The first quirky factor concerns cold soil temperatures at planting. Peppers do not like to have their roots in cold soil. Chilly soil causes peppers to go dormant Even when the soil warms, peppers may not fully recover, resulting in little or no fruit set. To prevent this, the minimum soil temperature for planting pepper is 70°F. The soil temperature should be taken early in the morning at a depth of 4–6” where the root ball is going to rest. Containers will reach 70°F first, raised beds will be a couple of weeks later, and in-ground beds will be the last to warm. Depending on how early you purchase your plants you may need to move them up into larger pots. One-gallon pots work well and will give the pepper roots plenty of growing space.

The second quirky factor is nighttime temperatures below 60°F. At this temperature peppers slow their development and at 55°F peppers may drop their flowers altogether. To prevent this, you can use polyethylene plastic tunnels, pulling the plastic over the peppers in the late afternoon to capture some additional heat when overnight temperatures are expected to be chilly. Instructions for DIY row covers and poly tunnels are in the link below.

The third quirky factor concerns heat. When the daytime temperature goes over 85°F, pepper pollen begins to shut down, at 90°F and above peppers often drop their blooms. To prevent this, we recommend putting shade cloth over your peppers on high temperature days. In addition to keeping the temperature cooler, the shade cloth is a great help in preventing sunscald on peppers.

Shade cloth comes in two types, woven and knit (lockstitch); we have found knit shade cloth works best and is resistant to rips, tears, and fraying. Shade cloth comes in percentages of shade provided. Choose one between 30%–50% for garden shading. You can find shade cloth in pre-cut panels or bulk rolls of various widths and lengths. To make sure you order the correct width, measure from ground level to ground level over the top of the hoops from side to side. Repeat this measuring process from one end of the frame to the other end of the frame to give the length. A simple frame using PVC pipe and 24” lengths of rebar (or pipe clamps) are quick and easy to assemble. This link will walk you through the process.

https://ucanr.edu/sites/ucmgnevada/files/333484.pdf

Although the following information is not vital, we have found these practices to be beneficial:

• Peppers are shallow rooted so a 2-inch layer of mulch will help keep the soil temperature cooler and the soil moisture consistent.
• Prep the soil with 2 inches of compost and a low nitrogen starter fertilizer; work gently into the top of the soil.
• Transplant peppers in the cool of the day, spacing them 18–24 inches apart to allow for good airflow. Peppers dislike having their roots disturbed; handle them carefully.
• Peppers do not tolerate overly wet or overly dry conditions. Keep peppers consistently watered especially during flowering and fruit set.
• High nitrogen feeding can result in low fruit yield. Place a side-dressing of aged compost or worm castings around pepper plants when the first flowers appear or feed with an organic low nitrogen fertilizer. Continue to feed lightly at 3–4-week intervals.
• Peppers appreciate additional mineral supplements of calcium, phosphorus, and magnesium as they are setting blooms.

If you pay attention to these three vital areas—cold soil, cold night temps, and high daytime temps—you will go a long way toward harvesting that “peck” of peppers. Take care to use the best practices and you'll be pleased with your results. The bounty of your garden will be a delight and treat for your friends and family.

Help Desk of the UC Master Gardeners of Contra Costa County (BHD)

If you have a history of “worms” in your apples, pears, or English walnuts, and have felt perplexed as to how to manage this problem, the very first step is to understand what is happening. When one understands that, the management becomes more understandable and approachable.

The “worms” are actually caterpillars, the immature stage of an adult moth. The life cycle is egg, larva (caterpillar), pupa, adult. The adult moth is mottled gray and small (½ to ¾ inch) and therefore hard to see and often goes unnoticed.

The adult female moth lays her eggs on or near developing fruit. The egg hatches and the caterpillar immediately will chew its way into the fruit where it lives and feeds. Entry holes are referred to as “stings” and typically exhibit a sawdust like residue called “frass”. If one sees a sting, the larva has already entered the fruit and is impervious to insecticidal sprays.

When it is ready to pupate, it will chew its way out and drop to the ground where it pupates in soil or leaf debris or under tree bark. After pupation an adult emerges and starts the cycle all over again.

The rate of development varies with temperature, proceeding more rapidly in warmer weather and climates. Depending upon the climate, codling moths can have two, three, and sometimes four generations per year. Our county has warmer climates inland and cooler climates by the coast. This means adult moths will start flying sooner and have more generations in the warmer areas and start flying later and have fewer generations in the cooler areas. Adult moths can start flying and laying eggs as early as March. The link below shows the approximate timing of the multiple generations.

https://ipm.ucanr.edu/PMG/PESTNOTES/pni7412-3.html

Codling moths can be difficult to manage, and a goal of 100% undamaged fruit may be unrealistic. A more reasonable goal would be to harvest enough undamaged fruit to meet your needs. In most backyard situations, the best course of action would be to combine a variety of the following non-chemical and low toxicity chemical methods early in the season.

Non-chemical:

• Pheromone traps (sticky traps laced with female pheromone to attract males) are not an effective management approach by themselves. They may be helpful if multiple traps are placed in a tree, but primarily they are used to monitor when adults are flying in order to time chemical applications. Traps can be purchased at most home and garden stores or online.
• Thinning your crop is important. The moths are most attracted to the place where two apples touch. Four to eight weeks after bloom, thin the fruit to only one per cluster, about every 6 inches.
• If you have thinned your fruit you may want to go one step further by “bagging” it. Although tedious and time consuming, placing bags over individual fruits early in the season, when the fruit is ½ to 1 inch in diameter, provides excellent control. The bag could be paper or cotton string. The link below provides a drawing of the bagging process. https://ipm.ucanr.edu/PMG/PESTNOTES/pni7412-2.html
• Beginning about six to eight weeks after bloom, and continuing every week or two throughout the season, check fruit on the tree for signs of damage (stings). Remove and destroy any infested fruit. Do not put the culled fruit in your backyard composting system, rather place it in green waste so it gets removed from your property.
• Since pupation takes place in litter on ground under the tree, keep the area continuously clean throughout the season, even though winter.

Low toxicity chemicals:

• CYD-X is a biological insecticide, a granulosis virus that affects only codling moth caterpillars. It kills by ingestion, therefore it must be ingested by the caterpillar prior to or as entering the fruit. To achieve this, it needs to be applied weekly beginning at the time of egg hatch. CYD-X is primarily available online.
• Spinosad is a biological insecticide, a bacterium that is toxic to insects in general. It kills by both contact and ingestion, therefore it needs to be applied at 10-day intervals beginning at the time of egg hatch. Spinosad is readily available at most home and garden stores.
• Adding 1% horticultural oil to either of the above improves effectiveness.
• Identifying the timing of egg hatch is key to the success of chemical applications. Egg hatch can be estimated by visually monitoring first stings or by using the UC Degree Day Calculator for codling moth https://ipm.ucanr.edu/calludt.cgi/DDMODEL?MODEL=CM&CROP=landscape

It is important to begin implementing control measures early in the season. The link below to the UC Integrated Pest Management website provides the detailed information you will need for implementation of your codling moth management program.

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7412.html

Photo credits: Three photos above: Copyright UC Regents - photographer Jack Kelly Clark

Help Desk of the UC Master Gardeners of Contra Costa County (EDC)

Aphids can be a scourge in the garden. There are over 4,000 species of aphids in the world, but fortunately only(!) about 250 species are attracted to the plants we grow in our gardens and landscapes.

Aphids are small, slow-moving insects that come in a variety of colors—green, yellow, brown, red, or black. They sometimes match the color of the plant they feed on, but not always. They have long legs and antennae, and usually have a pair of cornicles (tube-like structures) sticking out of their hind end. No other insects have cornicles. Some adult aphids have wings—this can occur when populations are high or during spring and fall—that can allow them to disperse to other plants.

Aphid reproduction is interesting. Adult females can give birth to up to 12 live offspring each day without mating. During warm weather, many aphid species can grow from newborn nymph to reproductive adult in a week. No wonder it seems like they appear overnight.

Aphids are attracted to plants on which they can feed. Plants that are actively growing are prime targets. Right now, these include plants in our winter gardens such as kale and broccoli and landscape plants such as roses, but also the many winter weeds growing abundantly in many neighborhoods.

Aphids have sucking mouth parts, somewhat like little straws. They use them to suck sap (which is a plant's sugar source). What they excrete is commonly referred to as ‘honeydew' which contains sugar and is therefore sticky. Ants are attracted to this honeydew and will actively “farm” the aphids and protect them against natural predators.

Many plants, especially trees and shrubs, can survive just fine with low to moderate numbers of leaf-feeding aphids. Damage can occur with larger populations. Yellowing leaves and stunted growth are common.

Aphids can also transmit viruses from plant to plant on many vegetable crops and ornamental plants. Symptoms can include mottled, yellow, or curled leaves, along with stunted growth.

Controlling aphids

Understanding their life cycle is key to their management. By checking plants twice a week while they are growing rapidly, you can catch infestations early. With small populations of wingless aphids, hosing them off with a strong stream of water works well. Once off the plants, aphids are unlikely to be able to return. You can also prune out the most infested parts. Make sure you also remove nearby weeds that can serve as a reservoir of new infestations.

Natural enemies are important for aphid control. Parasitic wasps lay eggs inside live aphids, causing them to turn into mummies. You can recognize these by light-colored aphid bodies with circular holes on top where the wasp has emerged. Lady beetles (especially the larvae), syrphid fly larvae, and green lacewings are voracious eaters of aphids. See this website: https://ipm.ucanr.edu/natural-enemies/

If spraying with water is not effective enough, insecticidal soaps and oils are the best choices for most situations. Oils include petroleum-based horticultural oils or plant-derived oils such as neem or canola oil. These products kill primarily by smothering the aphid, so thorough coverage of infested foliage is required. Soaps and oils kill only those aphids present on the day they are sprayed, so applications may need to be repeated. Although these products can kill some natural enemies that are present on the plant and hit by the spray, they don't leave a toxic residue.

It is easier to manage aphids earlier in an infestation than later when populations are high. Some aphids cause leaves to curl around them, protecting them from sprays and beneficial insects.

Prevention

• When you purchase new plants, inspect them carefully.
• Don't over-fertilize. Excess fertilizers, especially too much nitrogen, can stimulate plants to put out lush new growth that will entice aphids to set up home.
• Excessive pruning can also stimulate plants to put out attractive new growth.
• Use a row cover, especially on seedlings and new plants. This will keep out aphids but also protect from other pests.
• Control ants that can protect aphids.

For more information, check these websites:

https://ipm.ucanr.edu/PMG/PESTNOTES/pn7404.html#TABLE1

https://ipm.ucanr.edu/QT/aphidscard.html

Help Desk of the UC Master Gardeners of Contra Costa County (SEH)

We often get questions at the help desk from local gardeners who have lost many or sometimes even all their newly planted vegetable seedlings to one malady or another. Whether you have grown them from seed and tended your precious seedlings for many weeks, or have purchased them as young plants, this can be a heart-breaking occurrence. Here are seven steps you can take to give your young plants the best chance to survive and thrive.

Be patient and wait until the soil is the optimum temperature.
This applies for both purchased plants and for home-started seedlings. Your plants may have grown large enough to go into the ground, but if the outdoor temperatures are not yet at the optimal range, don't be tempted to plant them yet! When planted in soil that is too cold, many summer vegetable plants will just not grow. They are also more susceptible to being damaged or killed by fungal diseases. How does one know if the soil is the right temperature? The best way is to use a soil thermometer. A good kitchen thermometer will also work, although you may want to have one that is designated for use only in the garden. If you don't have a thermometer, watch for daytime high temperatures to remain consistently above 60 degrees and nighttime temperatures above 50 degrees. For more information on this, you may want to review our previous blog posting published on February 20th entitled: “Indoor Seed Starting."

Cool-season vegetables such as peas, cabbage, lettuce, carrots, cauliflower, broccoli, beets, and Swiss chard will do best when average temperatures range from 55 - 75ºF. Warm-season vegetables prefer temperatures that range from 65 - 95ºF. Examples of these are eggplants, tomatoes, beans, squash, melons, and peppers. Best planting times will differ for many vegetable varieties. Check seed packets or the planting guide listed below for information on the best dates for planting in your area.

CCC Vegetable Planting Guide-Interior Regions
CCC Vegetable Planting Guide-Coastal Regions

Avoid letting plants become pot bound.
Move your plants into containers that give them more room for healthy root growth. Transplanting into 4-inch, quart, and even gallon sizes is often necessary. Use a good quality soilless potting mix and avoid planting mixes and garden soil. To check if your plant needs a larger pot, gently tap the sides of the container it is in and carefully slide it out (soil, roots, and all) to look at the root growth. Transplant into larger containers before the roots begin to circle the edge of the soil, create a mat of roots at the bottom of the container, or grow out of the drain holes. Pot bound, stressed plants will often have early flower and fruit development. This can stunt their growth and impact the plant's health as well as reducing future harvests.

Harden off young plants to prepare them for their life outdoors.
Sunscald is a common problem in young plants and seedlings that have suddenly received more sunlight than they were previously accustomed to getting. Sunscald causes areas on the leaf to dry out and die, turning thin and papery and a white or light tan color. Most seedlings will bounce back from a moderate amount of sunscald damage and continue to grow new, healthy leaves. When the damage is so extensive that all or nearly all the leaf surfaces or areas of the stem are affected, the plant may not be able to survive.

To avoid this problem, plants must be hardened off. This is a process used to acclimate young plants and seedlings to the conditions outdoors. For seedlings that have been grown in a greenhouse, indoors under lights, or other protected environment, this is a crucial step. The hardening off process will take about 10 days to two weeks. Here is an excellent article from Penn State Extension with step-by-step instructions on how to harden off plants.
https://extension.psu.edu/hardening-transplants

Keep your plants safe from hungry pests- snails, slugs, earwigs, and birds.
Even the most experienced gardeners will lose some of their young vegetable plants to one or more hungry garden pests. My first suggestion is to always have a few extra plants to replace those that may get eaten. My second is if you have had problems in the past with one or more pests consuming your vegetable seedlings, start taking steps to control them before you plant. Don't wait until the damage is already done. The methods of controlling many of the pests are similar and include keeping your garden free of plant debris and favored hiding places, trapping, barriers, and baits. Baits that are safe for children, pets, and wildlife are available to the homeowner, and are very effective. Because they can take several days to take effect, it is best to use them in conjunction with the other suggested control methods. The best time to start using these control methods is several days to one week before planting.

Birds can also be a serious pest in the vegetable garden- especially early in the season as many vegetable starts are a favorite food. While there are many products advertised to scare birds away and keep them from eating your plants, bird netting is the solution that I find to be most effective. Make sure that the netting is raised above the plants to keep birds from reaching through to eat, and securely staked to the ground so that they cannot get underneath. Check your netting regularly, keep netting stretched snugly over supports, and avoid any loose ends that can trap and kill birds, lizards, and other wildlife. As plants mature, they are less attractive to the birds, and netting can often be removed. See one of our earlier blogs for more information on protecting your plants from a variety of pests: https://ucanr.edu/blogs/CCMGBlog/index.cfm?tagname=birds

Space requirements for healthy vegetable plants
Before planting it is important to consider the mature size of the plants, and the space necessary for them to grow and flourish. Vegetable plants do not do well in overcrowded situations where they need to compete for nutrients, water, and sunlight. They will tend to be stunted and much less productive than those that have plenty of room. For information on space requirements for a variety of vegetable plants, click here: https://ucanr.edu/sites/MarinMG/files/343708.pdf.

Transplanting tips, suggestions
If transplanting from flats with several plants growing in them, be sure to take up some soil with each plant as you carefully remove each one from the flat. If transplanting single plants from individual containers, try to remove them from the container with the soil as intact as possible to avoid root damage. This will be much easier to do if the plants have been watered recently and the soil in the container is well moistened. Choose a cool, cloudy day to transplant or wait until late in the day when the sun is low in the sky. Don't forget to thoroughly water your plants immediately after planting. If you have questions about the best way to handle and transplant seedlings, see this video from the Master Gardener Program of San Luis Obispo County:
https://www.youtube.com/watch?v=72dqbPZFgFY

Give your plants some shade after planting in the garden.
It is difficult to completely avoid damaging a plant's root hairs when transplanting. Root hairs are necessary to take up water and nutrients. Giving your plants some shade in the hottest part of the day for the first 5–7 days after transplanting will help keep them cooler while they regrow their root hairs. Garden shade structures do not have to be complicated and can either be purchased or made at home with items you may already have. Shade cloth, or even the plant flats used for carrying pots can be used. They are easy to set up and can be used year after year. Learn more about shading your plants in this link to a previous blog post:
https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=55005

Be sure to look at our Master Gardener Program website to find a wide variety of useful information. Our previous blogs can also be found here: https://ccmg.ucanr.edu/

Help Desk of the UC Master Gardeners of Contra Costa County (SMH)