Greenhouse Challenges

JoAnne Skelly — Associate Professor & Extension Educator Emerita, University of Nevada Cooperative Extension

November 21, 2017

Greenhouse management was not my career forte. My expertise is in ornamental plants and landscape design. Being involved with the non-profit The Greenhouse Project since its inception has given me a great opportunity to improve my understanding of how greenhouses work. You would think that growing plants in a greenhouse would be a breeze, since the environment is completely controlled. However, greenhouse growing has as many challenges as growing outdoors, although the challenges can be somewhat different. For example, there are often lots of insect pests in a greenhouse, especially one managed organically. Unlike outdoors, where nature might help manage pests with beneficial insects and predators, beneficial insects must be purposefully released into a greenhouse and then nurtured to keep them alive. Maintaining optimal day and nighttime temperatures can be extremely difficult. Greenhouses can get quite hot during the day and it always seems the heater breaks in the middle of a freezing cold night risking the demise of the entire crop.

Water management is imperative in a greenhouse, particularly when plants are grown in containers rather than in the ground, since containers have a reduced water-holding capacity. Not only is the amount, duration and timing of irrigation critical to plant health, atmospheric evaporative demand is too. Moisture in the air is necessary to keep plants from drying out, especially during the heat and intense sun of summer. However, air circulation is also essential to prevent water collecting on leaves, which encourages disease organisms. There is a fine line between not enough much moisture in the air and too much.

If an environment is too dry, plants do not thrive. Greenhouse growers measure vapor pressure deficits (VPD) to tell how much moisture is in the air. Cory King, The Greenhouse Project manager, has found that tomatoes really suffer if the VPD is not optimum. Measuring the VPD tells him when to mist to raise moisture content in the air to prevent the tomatoes drying out. With a slightly elevated VPD, research has shown an increase in photosynthesis and in yield in tomatoes. Yet, too high a VPD can cause tomatoes to crack (Iraqi, Gagnon, Dubé and Gosselin, It’s all about balance.

There is so much more to greenhouse production than sowing seeds, watering and waiting for perfect tomatoes. Using scientific methods allows plants needs to be met most efficiently, which increases productivity.

Managing Fruit Tree Pests

JoAnne Skelly — Associate Professor and Extension Educator, Emerita
University of Nevada Cooperative Extension

April 18, 2017 

My friend Michael Janik, of Michael’s Apples, is a fruit tree expert. He sent out an April newsletter with tips on pest control and said I could share them. “Look at your fruit trees. Notice that many of the buds are swollen and enlarged; the trees have gone from the dormant to the delayed dormant stage. Watch your trees more closely to see when the spring leaves begin to emerge signifying the next growth stage: ¼” green-tip.”

“Dormant, delayed dormant and up to ¼” green tip are the times to use dormant oil to control aphids, scales and other pests. The oil smothers the pests in the egg phase before they hatch. Dormant oil is one of the most benign pesticides (to humans), is easy to use, and is used in both organic-approved and traditional pest management programs.”

“Read label directions, use only products specifically recommended for your particular fruit tree or plant, and follow the label instructions, especially for clothing, gloves, eye protection and respirators. Use a different sprayer for the various applications; don’t spray insecticide or dormant oil from a sprayer that once contained an herbicide!”

Do not use pesticides when trees are in bloom!” You will kill the honeybees and other pollinators and reduce apple production.
“After blossom drop, the battle starts against the codling moth. The moth (about ½” long with coppery wing tips) lays its eggs in the spring; the larvae (dang worms) emerge and bore into the fruit, feed, and then leave the fruit, pupate and restart the cycle. The cycle repeats two or three times each year in northern Nevada.”   “Timing your spray to kill the larvae at hatch is the key to minimizing damage.”

‘Grow Your Own’ classes are being offered by University of Nevada Cooperative Extension to help you grow more of your own food with better harvests. The classes are at 6:00 p.m. at the Reno Cooperative Extension Office, 4955 Energy Way. The topics are: April 18 – Vegetable Garden Pollinators and Other Beneficial Insects; April 20 – Ins & Outs of Fruit Trees; April 25 – Vegetable Garden Pest Control; and April 27 – Successful Berry Growing Basics. The fee is $15 per class. To register, go online or call 775-784-4848. You can also purchase a flash drive with the information for all the classes including those that occurred earlier in April: Starting Plants from Seeds or Cuttings, Growing Tomatoes, The Challenge of Gardening in Nevada Soils and Attractive and Edible Landscapes.

Tucking Tools Away for Winter

JoAnne Skelly — Associate Professor and Extension Educator, Emerita

November 29, 2016

I am ready for a winter respite from gardening chores. The leaves have been raked. I cut back the lavender and other woody perennials. I fertilized the lawns. Now I need to winterize my tools. Are your tools cleaned and stored for winter yet?

Hand tools such as pruners and loppers need a good cleaning and perhaps a sanding, followed by an oiling. Use fine sandpaper to remove rust and to smooth wooden handles. Sharpen the blades and then wipe them down with WD-40 or lightweight oil. Clean and sharpen shovels and hand trowels too so future digging will be easier.

I’m lucky my mechanic husband takes care of all the power tools. I asked him what he does. He empties the mower of gas and runs it until it is dry. Or, you can avoid draining a gas tank by putting in a gas stabilizer available from any auto parts store. He also drains the engine oil using the drain plug in the bottom of the crankcase catching the oil in a drain pan to dispose of at a recycling center. With some mowers, you drain the oil out of the filler tube by turning the mower over (after removing the gas). After the fluids have been drained, he tips the mower on its side and uses a wide blade putty knife to clean under the deck, scraping off the built-up grass and dirt and taking care near the blades. He sprays a biodegradable all-purpose cleaner under the deck and allows that to sit for five minutes. Then, he hoses it off. After drying the area, he sprays it with a lubricant like WD-40. With the mower upright again, he refills it with fresh oil. Or, you can leave it empty, if you put a note on it that there is no oil, so in the spring you don’t start it without oil. He then cleans the top surfaces of the mower. He checks the air cleaner. If it is clogged with dirt, he blows it out with compressed air or replaces it. He takes the spark plug out, puts a little engine oil in the spark plug hole and pulls the start cord a couple times to lubricate the cylinder to prevent rust in the engine. Finally, he replaces the spark plug. Since sharpening a lawnmower’s blades requires that they be balanced carefully, have them done professionally.

Your tools will be ready to go when spring arrives.


Time to Plant your Fall Vegetables

Late Season Vegetable Planting

JoAnne Skelly – August 9, 2016 — Associate Professor and Extension Educator, Emerita

University of Nevada Cooperative Extension

My friend Karen recently asked me when to plant her fall vegetables. Midsummer planting is an excellent way to extend the growing season into the fall. I prefer gardening in the early spring and late summer. It’s cooler and the sun is less intense. Another advantage is that cooler weather improves the flavor of many vegetables. A trick to successful late season planting is to choose varieties with short growing seasons. The average first frost occurs between September 15 and October 1. Plants need to mature quickly before the hard freezes set in. However, with cold protection, crops often can grow into November and sometimes beyond.

From mid-July to September 1, the following vegetables can be seeded for a fall harvest: beets, Chinese cabbages (until mid-August), collards, kale, mustard greens, lettuce and radish (these last two only until mid-August), spinach, Swiss chard and turnips. Beets take 30 to 60 days to mature and survive temperatures in the high 20s. Chinese cabbages (50 to 85 days) and collards (40 to 65 days), survive down to 20 degrees. Kale needs 40 to 65 days to mature and the hardiest varieties survive down to 20 degrees. Leaf lettuces (40 to 60 days) and mustard greens (30 to 40 days) survive light frosts. Radishes can ripen within 30 days. With mulching they can be dug until the ground freezes. Swiss chard (40 to 60 days) and turnips (30 to 60 days) survive light frosts. Spinach (40 to 52 days) will also survive hard frosts if mulched heavily.

While late season veggies can be planted from seed, transplants at local nurseries does give a fall garden a head start.

For late season plants to thrive and mature on time, be sure to work the soil by turning in compost, organic matter and a balanced fertilizer (either organic or traditional). This will replace the nutrients used by earlier crops. Remove old stems and roots so seeds can germinate easily without plant debris in the way. Plant seeds at the proper depth per the label and mist the soil multiple times a day until they sprout. Once the seedlings are up, keep the soil moist. As the weather cools, mulch the plants to protect them Cover those veggies that tolerate only light frosts with row covers to provide extra cold protection.

If you haven’t planted veggies yet, you may want to plant now.


Protecting Pollinators in a Big Way

 JoAnne Skelly – June 28, 2016

Associate Professor & Extension Educator, Emerita – University of Nevada Cooperative Extension

We just completed National Pollinator Week, a designation that recognizes all that pollinators do for our food supply, environment and economy. Last year the Obama administration released a “National Strategy to Promote the Health of Honey Bees and Other Pollinators” led by U.S. Department of Agriculture (USDA). According to a USDA fact sheet, “honey bee pollination alone adds more than $15 billion in value to agricultural crops each year.” Honey bees are of huge benefit, but so are native bees, other insect pollinators, birds and bats.

In 2015 beekeepers lost about 40 percent of honey bee colonies in the U.S. Another threatened pollinator, the Monarch butterfly, has declined by 90 percent in its winter habitats in Mexico. Local gardeners report seeing fewer bees on their fruit trees. Under the National Strategy, USDA is striving to create more healthy habitats for pollinators, do research to better understand the cause of population declines, and raise public awareness about steps we all can take to help boost pollinator numbers.

Fifteen million acres of privately owned land are now enrolled in conservation practices to benefit pollinators. USDA is working with the U.S. Geological Survey to study honey bees’ use of conservation covers and to assess the effectiveness of conservation efforts to help honey bees. USDA’s Natural Resource Conservation Service recently created the Monarch Butterfly Habitat Development Project to establish and improve butterfly habitat. The U.S. Forest Service is restoring and improving pollinator habitat on national forests and grasslands.

The Agricultural Research Service is examining bee genetics, biology, breeding and physiology, focusing on bee nutrition, pathogens and parasites as well as the effects of pesticide exposure. The University of Nevada has received funding to research treatment for a bacterial disease in honey bees. The National Agriculture Statistics Service, another branch of USDA, just released results of its first Honey Bee Colony Loss survey.

You can join the Million Pollinator Garden Challenge, a nationwide call to action to preserve and create gardens and landscapes that help bees, butterflies, birds, bats and other pollinators. To do your part, start with a sunny location protected from strong wind with a nearby source of water. Native plants with different flower shapes and colors that supply nectar and pollen are ideal. However, many common ornamentals also feed pollinators. It is critical to avoid using pesticides throughout your yard. For more information on pollinators and what you can do in your own landscape and community go to University of Nevada Cooperative Extension has two excellent publications on native plants for pollinators. Go to


The Awful Earwig

JoAnne Skelly – June 21, 2016

People are asking about earwigs. Earwigs are easily recognized with rather alarming-looking pincers on their tail ends. These unappealing pests can devastate young vegetables, flowers, soft fruits or corn silks.

In spite of this, earwigs, believe it or not, are also beneficial. Being omnivores, they eat aphids, other insects, mites, nematodes, algae and fungi. They eat and break down organic matter, which includes dying and dead plants or ripened fruits. A negative is that they eat petals, pollen and seedlings too. Typical earwig damage on most plants is small holes in the margins of leaves, although whole seedlings may disappear. They also chew shallow gouges or holes in soft fruits such as apricots, strawberries or raspberries. Earwigs are often blamed for damage more likely caused by slugs, cutworms and other garden pests that, like earwigs, also hide in damp debris. Gardeners often assume injuries to fruit and vegetables are caused by the easily found earwigs, although the earwigs most likely arrived after the initial attackers did their damage.

Deter earwigs from nibbling on plants by circling plants with organic matter, such as compost or chipped bark, to provide a complex soil surface with many alternative organisms on which earwigs can feed. If your yard is already well mulched, and you suspect earwigs are chewing on your seedlings, raise the seedlings indoors and transplant them outside when they are large enough to withstand damage.

Earwigs are easy to trap. Place small cans with a half inch of vegetable oil in them around plants. Bamboo tubes, dampened rolled up newspapers, damp rags or pieces of hose placed near plants also make good traps, because earwigs like dark moist places. A clay or plastic pot filled with damp moss and placed upside down with a small gap at the bottom provides an inviting earwig abode. Place traps near plants just before dusk. Check traps the following morning and shake the trapped insects into a bucket of soapy water to drown them. Reset the traps daily.

Keep earwigs out of fruit trees by encircling the bark with a six-inch band of a sticky barrier. Diatomaceous earth at the base also works as a barrier. Remove boards, rubbish and plant debris in areas you want to protect to reduce hiding places. Raise pots and plant containers on stands or pot feet to deter earwigs from gathering there.

Don’t worry. It’s a myth that earwigs crawl into ears to burrow into the brain to lay eggs.

The Ever Popular Tomato

JoAnne Skelly – June 14, 2016

Gardeners like to grow tomatoes. There are over 2,000 varieties available worldwide. Many are hybrids. Hybrid tomatoes were initially bred to reduce disease problems and increase yield. Now, breeders focus on developing varieties that not only resist diseases and other problems, but also taste good. Some popular hybrids include ‘Early Girl,’ ‘Celebrity,’ ‘Big Boy’ or ‘Better Boy.’ In addition to these main season varieties, there are also big beefsteak tomatoes, small cherry tomatoes, such as ‘Sweet 100,’ grape tomatoes, and paste tomatoes. If hybrids are not your preference, traditional heirloom tomatoes are quite popular now. While they may or may not have natural disease resistance, they are known for good old-fashioned flavor and often-interesting appearance.

Beyond normal varietal differences or hybrid versus heirloom, a northern Nevada gardener must consider how quickly a particular tomato matures in order to get ripe tomatoes in our short growing season. The average last frost date varies. In some places, it’s the first week of May, in others it may be the first week of June. Coupled with a variable first frost date of September 1 to October 1, the shorter the maturity date, the more likely it is that a gardener will have ripe tomatoes before the first freeze. I prefer tomatoes with 50 day or less growing season.

There are two types of vines, indeterminate or determinate. With indeterminate, the vine grows throughout the growing season producing large plants and extending fruit production until frost kills the vine. With determinate types, vines stop growing when flowering begins, so these plants are moderate in size. Determinates put out a large single crop, almost all at once, and then they are done.

You can reduce disease incidence by trellising plants for good air circulation. Mulching around each plant will conserve soil moisture and reduce weeds. Water the soil rather than the leaves of the plant. With a good amount of organic matter in the soil, tomatoes need little nitrogen (N). If there is too much N, it will cause plants to grow an abundance of leaves but few flowers. However, with too little N, the disease Early Blight may develop. Fortunately, there are many tomato fertilizers available, either organic or inorganic.

Getting fruit to set is sometimes challenging because tomato blossoms abort when daytime temperatures reach 90ºF by 10 a.m. and pollen fails to develop if nighttime temperatures drop below 55º.

For more information on growing tomatoes, see

 Thematic Vegetable Gardening in Containers

Joanne Skelly – May 31, 2016

Vegetable gardening in containers not only rewards a gardener with tasty veggies, but also provides an enjoyable creative outlet. However, whether you plant your veggies in the ground or in containers, you may want to think beyond the traditional tomato plant. Think ethnic, global, regional or thematic. Try an Italian (tomato, garlic, radicchio, bell pepper, parsley), Asian (Japanese eggplant, Chinese cabbage, pea pods, coriander), Greek (tomato, eggplant, cucumber, garlic, fennel) or Mexican (hot peppers, summer squash, tomatoes, garlic, onions) theme. Do a pickle barrel (pickling cucumbers, garlic, dill) or summer salad garden (arugula, lettuces, cherry tomatoes). Plant a pizza (tomatoes, garlic basil) or salsa garden (cilantro, peppers, tomatillos, tomatoes). Or, come up with your own themes. Thematic vegetable gardens can be beautiful in a container. You can plant more than one plant in larger containers using trellises and tomato cages. Multiple plants can create colorful displays while providing edible treats.

Good vegetable production in containers starts with giving the plants the right depth in which to grow. Nine-inch to 12-inch deep pots work well for beets, leaf lettuce, onions, radishes, spinach, Swiss chard or carrots. Twelve-inch to 16-inch containers are best for broccoli, cabbage, cauliflower, eggplant, peppers, peas and cherry tomatoes. The largest containers, with depths of 16 inches to 18 inches deep or more are perfect for beans, cucumbers, potatoes, tomatoes and summer squash. All containers must have several drain holes in the bottom to avoid root rot.

Healthy productive plants start with good soil. Soil in containers should retain water and not dry out too quickly. However, it shouldn’t be too heavy or dense or roots will struggle to grow through it. For this reason, native soils don’t work in pots, unless mixed 50/50 or more with compost. Alternatively, there are many soilless mixes available specifically designed for containers. Choose only those that come sterilized. This will reduce the possibility of fungal diseases developing in seedlings or plants.

You can plant some of the thematic veggies in one container, complimentary herbs in another or all next to each other in the garden. Or maybe do an in-ground pizza bed and arrange the plants in the shape of a pizza. Doing a thematic garden is a great way to interest children in gardening and eating vegetables, especially if one container or plot in the garden is theirs.

No matter what you plant this year, have fun with it.


Know Your Fertilizers

JoAnne Skelly –  May 17, 2016

People use many fertilizer products to achieve a picture-perfect landscape and a high-yield vegetable garden, often without awareness of what is best for their plants, their soil or the environment. Timing of application and amounts of fertilizers are important because if applied in excess, they can be leached into groundwater and pollute our waterways.

The three major nutrients plants need are nitrogen (N), phosphorus (P) and potassium (K). N supports plant growth, making plants green and leafy. Too much N can make plants grow too fast and become leggy. It can interfere with flower and fruit development in vegies such as tomatoes and cucumbers. P supports root, flower and fruit development. Too little P may cause stunted growth and reduced yield. K is required for overall plant development.

Plants need other nutrients in smaller amounts such as magnesium, calcium, sulfur, iron, manganese, zinc and others. Nevada soils aren’t usually deficient in these unless the soil pH is outside the optimal range for most plants (5.5 to 7.5) or a soil is extremely sandy.

Fertilizers come in many forms. They might be liquids, granulars or soluble powders. A ‘complete’ fertilizer contains N, P and K. An ‘incomplete’ contains only one or two of the major nutrients. A ‘balanced’ fertilizer has equal proportions of the three. Fertilizers, by law, have a code on the label that tells you the relative proportion by weight of N, P and K, in that order. If there is a fourth number, it represents the percentage of sulfur (S) in the fertilizer. Other nutrients are indicated in parentheses after the N-P-K-S number, or in the complete analysis in the fine print on the label.

Fertilizers can be natural organic or synthetic inorganic. Plants take up their nutrients in the inorganic form, so the source of the nutrients does not matter to the plant. However, organics also help build overall soil health, structure and water-holding capacity, something inorganic fertilizers don’t do. Organic fertilizers are released slowly over time and are less likely to leach into groundwater. Organics have lower concentrations of nutrients than synthetic fertilizers. Inorganic fertilizers can be quick or slow release. Rapidly released nutrients are best applied based on the results of regular soil tests.

For more information read Dr. Heidi Kratsch’s publication “Fertilizing Your Vegetable Garden” available at under publications. Your local Cooperative Extension office can provide a list of soil-testing labs.


Gardening can be Tough

JoAnne Skelly –  May 2016

Gardening can beat up an aging gardener. When we are young, we rarely think about the amount of strain various gardening activities put on different parts of our body. We are flexible and resilient in our youth, and even if an activity hurts, we recover quickly. As we age, we lose flexibility and can easily injure our backs, knees and other body parts. We don’t recuperate quite as quickly. Since many gardening activities are repetitive, they can overwork muscles and tendons, particularly for those with previous injuries or arthritis. Stamina and balance can decline.The trick to staying an active healthy gardener is to garden smarter to reduce injuries and strain.

One of the reasons we get injured more easily as we age is that we don’t have proper posture or pelvic and spine alignment. We can get away with improper body mechanics in a 20- or 30-year-old body, but the older we get, the more strain our bodies have experienced and the more likely we are to get injured. Our bodies suffer wear and tear like any machine. I found out from my yoga instructor, Angela that I have been standing, weeding, raking, lifting and doing most other gardening activities all wrong from a body mechanics standpoint. After 35 years of gardening, I have put an inordinate amount of strain on my lower back and shoulders. I never lifted nor carried the weight I did lift correctly. Now, I’m paying for not knowing then how to use my body properly.

To reduce the hazards of gardening, use the right tool to reduce the force needed for a task and use it with the body in the correct position. Climbing on ladders is riskier so have someone nearby, just in case. Be careful of tripping on paths and surfaces. Take more frequent water breaks and rest periods.

We often forget about taking care of ourselves. Some gentle stretches can help warm up muscles before getting started or upon completion. Is it necessary to buy supplies in 50-pound weights? If it is necessary to carry something heavy, remember to use those thigh muscles when lifting. Avoid bending at the waist. Try bending knees instead. Asking for help is not a sign of weakness or old age; it is an indication that we are in tune with our bodies and smart enough to know our limitations.

Come to The Greenhouse Project’s  plant sales in early Spring and Summer to purchase flowers and vegetable starts. The Greenhouse is located on the east side of Carson High School.


Have You Planted Veggies Yet?

by JoAnne Skelly – April 2016

April Fool’s Day is past and I hope no one was fooled into planting their tomatoes outside yet! However, I’m sure some avid gardeners have planted their “very hardy” vegetables: asparagus crowns, broccoli, Brussel sprouts, cabbage, kale, lettuce, onions, parsley, peas, spinach and turnips. “Semi-hardy” vegetables such as beets, carrots, cauliflower, parsnips, radishes, Swiss chard and potatoes are planted from April 1 to May 1. “Frost-tender” veggies, including celery plants, green beans and sweet corn, go in the ground after May 15. The common favorites: cucumbers, eggplants, peppers, squash and tomatoes are all “cold-sensitive vegetables” and are best planted one to two weeks after May 15 to June 15.

Be aware that these dates are guidelines. Each area has its own microclimate and you need to know whether your last frost day averages May 15 or later. As I have mentioned in previous articles, I don’t usually plant cold-sensitive veggies until after June 1 in my part of Washoe Valley, unless I use season extenders.

A traditional season extender is the hot cap, used over individual plants. “A hot cap is anything that covers a plant to retain the heat around it. Historically, large jars with the bottoms cut out were used for this purpose” (Gatzke, University of Nevada Cooperative Extension). Walls of water are commonly used, readily available, season extenders. They are plastic sleeves that go over plants. They are made up of about 16 cylinders that you fill with water to absorb heat during the day and keep plants warm at night. Supposedly, when you use them, you can plant cold-sensitive veggies six to eight weeks prior to the last frost and they will be protected down to 16 degrees F.

Some season extenders can be made from materials on hand. Put a clear glass or plastic panel in the top of a box to create a “hot box.” Place trashcans or upside-down 5-gallon buckets over plants at night and remove them during the day. Or, place a paper shopping bag over your plants at night. Weight the handles down so the bag stays in place. Blankets laid over arched frameworks will protect plants without weighing down tender seedlings. Or, you can buy commercial “frost blankets” or “floating row covers.” Floating row covers don’t need a structure to support them because they are lightweight. They can provide an additional seven to 24 degrees of protection while still letting light through.

For more information go to and search for “Plant Season Extension in the Desert” under Publications.


Controlling Worms in Apples Begins Now

by JoAnne Skelly – April 2016

If you had apples with worms last year, it is likely you will have wormy apples this year too, unless you take precautions.

Worms in apples are the larvae of codling moths. These relatives of butterflies also attack pears, plums and walnuts. Each female moth lays 30 to 70 tiny disc-shaped eggs singly on the fruit, spurs or nearby leaves. After hatching, the white to light pink “worms” with dark heads bore into the fruit. Later, the caterpillars leave the fruit and look for sites for pupate overwinter before becoming adults in the spring. Moths are active only a few hours before and after sunset, and they mate when sunset temperatures exceed 62 degrees F. There can be two to three generations per year.

Control of codling moth starts with good sanitation. Cocoons (pupae) overwinter in protected areas under the bark on trunks, in debris under the trees or in soil. To reduce new populations, gently remove the loose bark on the trunk and destroy any cocoons you find. Get rid of any fallen apples or leaf litter from last year. Do not compost any of these materials. From late spring through harvest, pick up fallen apples daily to reduce reproduction sites.

Another method to manage these annoying pests is to select varieties less susceptible to damage, such as early maturing apples and pears. A labor-intensive way to keep the worms out of fruit is to bag as many individual fruits as you want to eat. Do this when the fruit are ½ to 1 inch in size. Thin the fruit to one per cluster. Then cover with a standard brown lunch bag or generic ziploc-type bag and seal it. The apple will grow inside. Red apples will be a light color when they develop in the brown bag, but those in plastic bags will be true red. You may have to poke a tiny hole in the plastic bags if water or condensation accumulates.

Timing the application of insecticides for codling moth control is difficult. Products must be applied just as the eggs are hatching, but before the caterpillars go into the fruit. According to Michael Janik at Michael’s Apples, first spray at 100 percent petal drop. Determine mating time using pheromone traps. Spray twice per hatch seven to10 days apart. For excellent detailed information on the timing of insecticides, sign up at for the most recent newsletter. Or, read the article from University of California at Davis: