Farmer Help on Postharvest Apples in Kyrgyzstan

Recently I did some postharvest work in Kyrgyzstan for ACDI/VOCA, virtually online, with trainings conducted by an experienced local trainer, Azamat Mamytov, through the ACDI/VOCA office head and coordinator Mira Arynova. 

https://www.acdivoca.org/contact-us/

Wbere is Kyrgystan?

https://geology.com/world/kyrgyzstan-satellite-image.shtml

Where in Kyrgyzstan

Picture of Kyrgyzstan and where farms were located. 
https://geology.com/world/kyrgyzstan-satellite-image.shtml

The training was conducted in the area of Kyrgyzstan bordering Uzbekistan and Tajikistan in the Osh and Batken Regions with the capitals in these districts of Osh and Batken, respectively.

Problem

These farmers are producing fruits and vegetables with availability storages due to the perishability of their crops and small size of their farms. Each orchard has an average size of 35 to 100 trees consisting of primarily peaches, cherries, and apples. Farmers are forced to sell their products immediately after harvest even if the price is low primarily due to a lack of cold storage facilities and knowledge how to use it. To add value to their produce, fruit and vegetables must be harvested and stored according to best practices. But farmers have limited knowledge on the best practices to use for the long-term storage of their crops. The lack of storage facilities and knowledge prevent them from increasing their farm income.

Assignment Objective

Workers sorting and grading apples for different markets

The objective of this assignment is to assess the harvesting, grading, sorting, cold storage practices and facilities in two promising villages and provide practical consultations specifically on preserving the longevity of these crops from harvest to market. The US-based volunteer will work with Azamat Mamiyov to prepare trainings on the postharvest practices that best meet the needs of the local farmers and upgrade their current level of knowledge. The US-based volunteer provides technical assistance and aids in the preparation of handouts for these and future participants.

Example of improved storage facility for local farmers.

What was Accomplished?

Because of the trainings made by Azamat and the successes of improved cold storage practices and marketing, approximately 80% of the farmers said they would like to improve their harvesting and cold storage practices. A major roadblock was the size of their operations. Discussions ensued regarding forming informal farmer agreements. Insights were given on what farmers might do to improve the quality of their products being sold. Discussion ensued about forming a formal storage and marketing cooperative among farmers.

For more information on this in Russian contact marynova@acdivoca-kg.org or Bob Morris for the English version at extremehort@gmail.com

Repotting Citrus Trees in Containers

Q. I saw your article in the Las Vegas Review Journal newspaper about renewing soil in a container every few years. I have a dwarf Meyer lemon tree in a large container that's about three years old. It's doing well and I got about a dozen lemons last year. When should I replant the tree?  I suspect winter.  Is that correct?

Citrus can be replanted into larger containers when it gets bigger but the soils should be "renewed" or at least partially replaced every three to five years.

A. It is hard to say when to replant but I should think somewhere between three and five years. Exactly when, I don’t know. It depends on the condition of the soil that was used at planting time and the growth of the tree. 

How to Repot a Citrus

Poor soils should be replaced sooner. Trees with lots of new healthy growth will need soil replacement sooner. Adding fertilizers, only, to the container soil will not improve the soil. Just like in Dust Bowl days it will “wear out” the soil. When the tree shows signs of poor growth or poor color is a good sign that the soil should have been replaced prior to this happening.

Time of year to replant container trees? Right after harvest.

What Kind of Acacia is This?

 Q. I need to replace this acacia tree; in a very shaded area of our yard. Is it a shoestring acacia?

A. Probably not. I posted the Shoestring Acacia flowers below. It is native to Australia and commonly flowers in mid winter in Las Vegas, north of the equator. 

Shoestring Acacia flowers

Most likely it is called Mulga or Mulga Acacia. Check out Mulga aneura from this website in Phoenix/Tempe.

http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/acaciaaneura.html

Bottle Trees Dropping Leaves Probably Water Related

 Q. My purpose for writing is that the bottle trees that I planted last year and until now have thrived, have suddenly been stripped of all of their leave at just the very top. The rest of the trees and the leaves look healthy. I live in a very windy area, and my landscaper suggested that the wind stripped the leaves. I have doubts that this is the case since my next door neighbors' bottle trees which are the same age look perfectly healthy. The trees have been been watered on a drip system twice a day, three time a week for the past month. I have 10 trees that look like this. Any advice will be greatly appreciated.

Bottle trees can drop leaves if they are too wet. They grow along streambanks in the dry parts of Australia.

A. From the sound of it and the pictures you sent it sounds more like a watering issue – the soil staying too wet between irrigations. Bottle trees have sensitive roots to wet soils…the roots will easily suffocate if the soils stay wet. This type of overwatering can be seen in the tree by its loss of leaves. Unfortunately we often see the same results when the tree is not given enough water but I don’t think that is the case with your tree.

Right now (Late spring, April) we should be watering trees and shrubs once or maybe at the most twice each week. When temperatures get warmer in about May or June is when three times a week watering is most common. Depending on the soil and its drainage would determine if watering three times a week is okay now. Watering that often this time of year would be okay for very sandy soils with very good drainage.

You can find out if the tree roots are ready for another irrigation by using a soil moisture meter stuck in the soil.

https://xtremehorticulture.blogspot.com/2018/09/use-houseplant-moisture-meter-to-know.html

https://xtremehorticulture.blogspot.com/2018/04/when-to-change-irrigation-clock-and-how.html

https://xtremehorticulture.blogspot.com/2018/12/moisture-meters-and-rebar-tell-you-when.html

https://xtremehorticulture.blogspot.com/2013/07/bottle-tree-dropping-leaves-could-mean.html

https://xtremehorticulture.blogspot.com/2013/05/bottle-tree-with-dying-branches.html

Consult this expert on Bottle trees growing in the Phoenix area:

http://www.public.asu.edu/~camartin/plants/Plant%20html%20files/brachychitonpopulneus.html

 

Wilting Rose Flowers and Thrip Damage

 Q. I am attaching 2 pictures of my rose. One wilts over even though it is getting watered regularly. It does get the morning sun In Pahrump.  My other roses do not do that. Any information you can give me will be appreciated.

I dont know if this is thrips damage or not but it is common on roses in the spring and it does look like this.

A. I think this is thrips damage to the flowers and probably Western Flower Thrips. Try an insecticide containing Spinosad for control. I think your roses have the very small insect called Western flower thrips. Very common now to see thrips on roses. Spray and contain them before they spread to other flowers.

Older Nectarine Dieback Probably Borers

Q. I have a question about the health of my nectarine tree. I had this tree planted 17 years ago and it has thrived every year since…until this year. Normally it is totally covered with blossoms and new growth. This year there are only a few scattered signs of growth. Most of the tree is barren. What could cause this? Is the tree dying?

Nectarines are close relatives to peach. Peach and nectarine are short lived trees primarily because of borer problems in the Las Vegas valley.

A. The most common reason for sudden tree death is borers. Look for peeling or flaking of the bark usually on the west or south side of the tree. They are actively feeding on the trees right now but the dieback usually shows up when it gets hot. 

I see it is in the lawn. Other reasons can be damage to the trunk from lawn mowers or line trimmers and then attack by borers. You might try a soil drench of a borer control chemical from Bayer. Then the trunk needs to be protected from direct sunlight. But if it is peach, that is pretty old for a peach tree. Anything over 15 years old I consider old for peach due to borers. Peach or nectarine. It's the same DNA just the fuzz is missing. They live about the same length of time.

If you use the Bayer product you cannot eat the fruit from this tree until it is no longer applied. It would have to be applied now.

Listen to My Desert Horticulture Podcasts

I am broadcasting my Desert Horticulture podcast though Buzzsprout but you can also find it on Apple Podcasts, Spotify, Google Podcasts, Stitcher, iHeart, Deezer, and many more. They typically last about 20 to 30 minutes and a must for those wanting more information than my blog offers.

Aphid Control on Apple Flowers

Q. I have a Granny apple and Meyer lemon tree. I just saw that I have a bunch of these bugs on the flowers. I would like to know if I should kill them or leave them alone. I also have bees pollinating the flowers so I don’t want to spray any chemicals that may harm them. If I have to remove the bugs is there any way to do it without harming the tree or the bees?

A. Those are aphids sucking plant juices to feed their young. Their numbers will continue to grow until it gets hot. 

Horticultural oil or dormant oil is sprayed on trees and shrubs during warm and windless days in the winter. It eliminates soft bodied insects like aphids.

You missed the winter application of dormant oil or you would have eliminated nearly all of them. Not much you can spray now without hitting some bees once the flowers are open like that. Wait until the flowers have formed apples and then spray. 

Alternative: You can use an oil spray like a dormant oil or soap sprays if it is below about 90F and the flowers are gone and fruit has started to form. Or pull off the flowers and spray and let the flowers reform again later. They will.

A. 

Which Citrus Should I Grow in My Desert Climate?

Citrus is meant for subtropical and tropical climates. Learn which how to select, grow and maintain this type of fruit in our desert.

Citrus grown in the Las Vegas valley

Long-Lasting Effects of Freezing Temperatures

Join me on this episode of Desert Horticulture. I discuss the long-lasting effects that spring freezing temperatures can have on plants.

Winter cold damage and bronzing of the leaves

Supplemental Lights Might Not Be Necessary for Citrus Growing in a Garage

Q. Because of the winter cold weather, I move my citrus trees growing in containers into my garage where it never gets below 40.  I added three fluorescent lights fixtures with grow lux bulbs per light fixture and they are hanging a few inches above the trees. Will this be sufficient light to keep the trees from being starved for light?

A. Although it’s less intense than outdoor sunlight this will work. I’m guessing you keep these citrus trees in your garage all winter long. But I’m wondering if you even need all that!

Interior of a peach flower showing the ovary. A fresh, good looking ovary after a possible freeze tells you it will probably produce a fruit.

           Winter freezing temperatures low enough to kill flowers normally start around mid-December. Usually by mid-February these temperatures are over. Although rare, sometimes we never experience freezing temperatures anywhere in the valley. Infrequently these temperatures are “patchy” and can start in mid-November (as they did in 2020) and can stretch into mid-March (as they did in 2021).

Recording Thermometer 

Inexpensive recording Taylor thermometer with two temperature probes. It used to run about $12.

Accuweather app for cell phone

Do you see why I recommend putting a recording thermometer in your landscape! I also recommend downloading a weather app on your phone for predicting upcoming freezes.

Different landscapes experience different temperatures. Oftentimes these different landscapes follow different weather patterns. These weather patterns determine your level of success in our climate. It would be much simpler for growing citrus if our climate was colder or warmer. But it’s not.

Low Light Levels Can Substitute for High Light Levels

I’m also wondering if your citrus even need the extra light. If temperatures are cold in your garage then the entire plant goes into “hibernation” and there is little need for light. For many plants this “magic temperature” is around 40 to 45° F. Also, the darkness inside the garage can delay flowering.

Because the intensity of light is so low, I would leave these lights on for 16 to 18 hours every day. Long-term low light accumulation can sometimes substitute for short-term highlight intensity (think sunlight). Because of these long light intervals, you might see earlier flowering in these trees.

 

Citrus in Containers? Maintenance More Important

Q. A horticulturalist suggested to put my dwarf citrus trees in the biggest pot I have room for or can afford and they will be happiest there. A person at a local nursery said to not move a tree from a small pot to a much larger pot and suggested the new pot be no more than 2 inches bigger in diameter than the small pot. The two questions seem to be in conflict. What do you think?

The most important practice comes about three to five years after planting into the container; replacing soil and root pruning.

A. Both answers are acceptable and pot size is not an issue as long as it is big enough. What is more important is the maintenance needed every few years for plants growing in containers. The soil in the container gets “worn out” and the roots need to be trimmed. Perhaps think about these containers like an aquarium; every few years plants in containers need to be removed, fresh soil added, the roots trimmed, and the plant repotted. This maintenance practice reinvigorates the plant and helps it live longer with fewer problems.

Selecting Citrus for Containers

Calamondin, or calamansi in the Philippines where it is native, is a small citrus that is suitable for containers. But it is sensitive to winter freezing temperatures.

When selecting citrus trees for containers make sure the tree is a dwarf or smaller in size. Smaller citrus like lime trees, calamondin, and kumquat, although variable in how much cold they can tolerate, are naturally small in stature. Oranges, lemons and larger citrus on dwarfing rootstock can also work but may be difficult to find. Look for the word “dwarf” on the label.

Containers Get Hot in the Desert

Also important is the transfer of heat from the sunny side of the container to the roots. Temperatures in the summer can be 170°F on the exposed side of the container. Consider growing container plants inside another container so the inside container is protected from direct sun by a fancy decorative exterior container. The shade from the exterior container prevents the sun from heating up the interior container.

Shade Cloth Needed for Lemon Trees?

Q. I just planted a Lisbon and Meyer lemon in full sun. Do I need to put shade cloth over them in the summer? I put shade cloth over my raised bed vegetable garden. They are planted along a northeast facing wall and not surrounded by rock.

Eureka Lemon growing in Las Vegas. Eureka lemon is a true lemon.

A. It’s a good location for fruit trees but I’m not sure how your citrus will perform in your landscape locale. Its touch and go in our climate. Much of their performance depends on the winter and spring temperatures of your landscape location. If temperatures are very low during the winter, Lisbon and Meyer trees might both get killed. Meyer lemon is more cold hardy, but in a very cold location, or during a very cold winter, it can be damaged or worse. If there are spring freezing temperatures, you might see less or no fruit produced on one or both trees.

Probably Meyer lemon which is not a true lemon. It doesnt have that lemon shape, it is round instead, and it shows off its orange heritage when it ripens but still tastes like a sweet lemon.

‘Lisbon’ is a normal lemon tree. ‘Meyer’ is not. Meyer lemon fruit tastes like a lemon but is actually a citrus hybrid with sour fruit. ‘Lisbon’ is 5 or 6 degrees more tender to winter freezing temperatures than Meyer lemon so it may need winter protection in your landscape locale when Meyer doesn’t.

Shade Protection?

Citrus doesn’t need shade protecting it from our desert sun. Citrus grows in full sun in the Yuma area, so it doesn’t need shade cloth here either. However, the first year after planting it might be a little shocked from its transfer from coastal California nursery to the harsher Mojave desert so it may develop some leaf yellowing or leaf drop the first year. Give it a chance to acclimate to this desert area which is no worse than growing in Yuma if the soil is improved at planting.

Minneola Tangelo. Orange, Pomegranate Not Producing Fruit

Q. I've had a dwarf Minneola Tangelo tree for about 4 years that gets morning sun, but I've gotten fruit off it only once. I've had an orange tree for about 1 year and a half that gets full sun; it had blossoms, but they all fell off before the heat of summer even began! I planted a pomegranate tree in full sun this past Mother's Day.  When I bought it, it had blooms on it; they also all fell off.

Unknown young pomegranate variety after maybe two years in the ground. Some pomegranate varieties are precocious...meaning they produce fruit early while other varieties produce fruit the first year. 

A. There are several different issues with your fruit trees. The Minneola Tangelo flowers only once in January and February. The same will be true of most sweet oranges. If there are freezing temperatures during this time at your landscape locale, then you may get little to no fruit when this happens. When your landscape gets winters with no freezing temperatures then each flower will produce fruit.

Late freezes

           It only takes a couple of degrees below freezing for a very short time to eliminate the flower and fruit. Multiple freezes during the spring results in total fruit loss. You may see fruit from these trees in the future, but it depends on the occurrence of spring freezing temperatures.

Be patient growing most citrus here. Citrus is more productive when there are no winter or spring freezing temperatures such as in Yuma, Arizona. Periodically we get winter freezing temperatures that can outright kill different types of citrus trees. The only reliable citrus for producing fruit in our climate are the so-called kumquats. This is because they are very cold hardy and flower all through the year.

Not Old Enough

Pomegranate loss of fruit is a different story. Pomegranate flowers through most of the year because the flowers are produced on “current season wood”; new growth and not last year’s growth. Some pomegranate varieties are more precocious than others and you will see fruit the first year they are planted. Other varieties produce fruit in the second or third year after they are in the ground. Just be patient and they will produce fruit. Plants frequently produce flowers but no fruit when they are young. It is an indicator that next year they may start fruiting.

Check Flowers of Fruit Trees for Freeze Losses

Myer lemon (not a true lemon) fruit ready for harvest. Its orange color and round shape shows off its orange fruit heritage.

Why doesn’t my ‘Meyer’ lemon tree produce any fruit? 

I was reminded of this question when I estimated the fruit production this year in a Las Vegas Orchard. I use a particular variety of pluot called ‘Flavor Supreme’ as an “indicator tree” for predicting the probable fruit load that year. I saw no fruit developing and I saw no remnants of flowers on these trees. I knew there was a late freeze that came through that orchard during the spring, probably two or three weeks ago.

Tearing open a flower soon after suspected freeze damage will tell you if the fruit will fall off dead or it is alive. In this case the ovary inside is green so it shows the flower will most likely produce a fruit.

           How did I know all that and how do I relate it back to ‘Meyer’ lemon? First of all, recognize it only takes a 1 or 2°F difference in temperature between having a tree loaded with fruit versus having a tree with few fruit. If this temperature difference comes along two or three times during the spring when it’s trying to flower, then voilà, there is no fruit produced that year.

All Flowers are Sensitive to Freezing

           The most tender parts to freezing temperatures of any fruit tree is its flowers. When flowers are open is the time when it is most sensitive to freezing temperatures. The tree itself is usually fine but not the flowers. If a very light freeze occurs in the spring only once when the tree is flowering, then fruit production is reduced. If a light freeze happens two or three times, maybe a week apart during the spring, then the fruit is probably eliminated for that year. However, if there is a single “hard” freeze (4 or 5 degrees below freezing or more) as flower buds are “awake” then, most likely, all fruit will be eliminated for that year.

           Flowers are killed by freezing temperatures depending on their stage of development. Flower buds during the dead of winter are very tolerant to freezing temperatures. But in the spring, when the plant begins to “wake up” from its winter sleep, they become more and more sensitive to freezing temperatures as they approach opening.

Open flowers are the most sensitive to freezing temperatures; 1°F below freezing for a very short time kills the single chance it has for fruit. Once a flower dies, it cannot produce fruit. If the flowering time of a fruit tree lasts three weeks, then it has a better chance to produce fruit as more flowers continue to open. If only 5% of the flowers are needed to produce a full load of fruit and all the flowers are dead, there is no fruit for that year.

Pollen Alert and Hay Fever

If bermudagrass flowers like this one are left to release pollen in the air, they will cause "hay fever". That's why common bermudagrass is not permitted for planting in Clark County, Nevada.

Pollen Alert

That’s what we see on our advisories in the early spring regarding pollen from mulberry, ash and junipers. The pollen alert continues through the “pollen season” as we go from mulberry to pine to olive. Pollen season might last until May. Right now we’re in “mulberry season”. Some pollen like mulberry is light enough and can be pushed by the wind and carried by pollinators like honeybees. This type of pollen causes “hay fever” while others are considered “sticky” or “heavy”, too large to travel long distances in the air and not considered allergenic.

Male flowers from the 'Bonita' ash tree. Because this ash tree is male, it produces only male flowers. Great for producing no seed but not if you dont want pollen.

Hay Fever

            “Hay fever” was a misnomer from the start. It was an old historic association with the cutting of hay in the spring and not paired with flowering of plants that cause the release of pollen. Back then pollination by plants was not studied much. Tree and shrub pollen was not considered responsible for “hayfever”. Most allergenic pollen comes from uncontrolled, wild grasses growing where rain was available. These allergies were caused by pollen floating in the air but the idea of “pollen fever” never caught on. Until recently people with severe symptoms were told to move to the desert Southwest where “pollen fever” was never considered much of a problem. Maybe that was the case back then, but they are wrong now!

Common bermudagrass flowering and it will seed next spreading pollen and seed everywhere. When bermudagrass escapes mowing, it creates pollen, allergies and seed.

Desert and Hay Fever

            As people moved to the desert Southwest and started planting more and more “desert trees” like Acacia, Mesquite and Palo Verde, “pollen fever” (aka, hayfever) developed into more of a problem. Typically, trees and shrubs with large showy flowers like oleander do not contribute much to the “hayfever problem”. This pollen is heavy or sticky and did not travel in the air far from the flower and the plants released pollen too large to cause “allergy problems”. Most of the “problem pollen” comes from “non-showy” flowers commonly found on olive, mulberry, pines, ash trees, mesquite and the like.

Oleander flowers are quite "showy". Showy flowers are not typically allergenic because the pollen is large and/or sticky.

Planting Restrictions

            Now we have planting restrictions in population dense Clark County that prohibit the planting of male mulberry trees or olive trees that produce lots of fruit. So, is it “illegal” to plant mulberry trees in Clark County? Yes and no. It is “illegal” to plant male mulberry trees but not the female trees.

Mulberry flowers are called "catkins". Flowers in mulberry are like ash trees; they are either male or female depending on the sex of the tree.

How about olive trees? Yes and no, but for a different reason. Olive trees always have both male and female parts in the same flower so we focus on the so-called “fruitless mulberries” and hope that these trees reduce “hayfever” in large communities. Mulberries, similar to ash trees, are bought as either male trees or female trees. As I have always said, plant sex is much more interesting than animal sex because of its diversity.

Olive trees are both male and female so their flowers, unlike mulberry and ash, contain both male and female parts. 

Making Pineapple Guava Set Fruit

Q. Does pineapple guava need a pollinator plant to produce fruit? The edible flowers bloom in May and have the wonderful taste of cotton candy! Should I get my pineapple guava tree a boyfriend?

Flowers of Pineapple Guava

A. First, let’s talk terms. A pollinator is an insect that helps plants produce more fruit by transferring pollen from one plant to another. Examples of pollinators are honeybees. A pollenizer is the plant that supplies this pollen to another plant to help it produce more fruit. So, I think you are asking for a pollenizer plant for pineapple guava.

A pollinator, honeybee, visiting a peach flower and it will encourage fruit set.

Now let’s talk pineapple guava. If the flowers are pollinated properly by a pineapple guava that is not exactly the same as the mother plant (pollenizer), the flowers will produce fruit. Some plants may be even self-fruitful to a degree. The amount of fruit produced depends on the number of flowers it produces and closeness to a pollenizer plant.

To make sure to get fruit from the flowers, give the plant a “boyfriend” (or girlfriend). The reason for this are because of its genetics. In technical terms, the flowers can be non-receptive to pollination by the same or similar plant (variety or cultivar) depending upon genetics. So to make sure you get fruit, plant two different varieties of a pineapple guava in close proximity, otherwise it might be a trickle of fruit at best. The flowers of pineapple guava are edible and the taste is not affected by a pollenizer.

Pineapple Guava and the Desert

Pineapple guava performs well in desert landscapes. They can handle our heat and they can handle our cold. They can even handle a lot of the rock mulch used in many landscapes. But they are “normal” water users (mesic) and not xeric like many of our native desert plants.

Flowers of pineapple guava with the same genetics are "self infertile"... in other words as much as the honeybee visits these flowers they will not set fruit. Even if the honeybee visits other pineapple guava, if they are too similar genetically then they will not create fruit. But the flowers are still yummy!

Pineapple guava is a good choice for our desert climate in landscapes, but they are not true “desert plants” so they grow better with a little bit of organics like compost mixed in the soil at planting time.

What is "Flowering Wood"?

Q. I have a star jasmine that is very woody growing behind some front greenery. I heard you mention once not to prune “flowering wood”. What does that mean?

Peach flower buds opening on peach "flowering wood". Sometimes, as in the case of peaches, the flower buds are formed the previous year they bloom. Other times flower buds (as in the case of oleander and Texas sage) they are formed on the newest spring growth. This creates a slight delay in flowering after pruning in the spring and summer months.

Texas sage (ranger) produces flowers on "current seasons wood" so if they are pruned when growing there is a pause in flowering until new growth has time to put on growth with flowers on it.

A. It means pay attention to the time of season you’re pruning and its relationship to when the plant produces flowers. 

Warning: we are talking about plants valued for their flowers, not fruit trees! Fruit trees are pruned at a different time because we value their fruit. The flowers are not as important to us in fruit trees. 

If you remember one thing, remember this; the best time to prune any plant valued for its showy flowers, is as soon as possible after it finishes flowering. Enjoy the flowers, and then prune!

Shrubs like oleander that need to put on some new growth to flower will not flower after severely cut back until it reaches close to its mature size, which in some cases can be quite large.

If it’s in the spring, prune it for flowering after it finishes in late spring. If it flowers all during the growing season, then wait until fall or winter when it stops flowering. Avoid all dramatic or “heavy” pruning of nearly all plants during the summer heat.

            Plants need time to produce flowers. Some plants also need the right time of year. If plants produce flowers all season long when growing, then wait to prune them until they finished their show by mid fall or early winter.

Probably one of the best known examples of flowering at certain times (photoperiodic flowering) is poinsettia which must only get a certain number of hours to create "flowers". Light for longer periods than this or shorter only produces green leaves.

Star jasmine typically produces flowers after a flush of spring growth; not right away in the spring. The time of flowering for this plant is more similar to oleander or Texas sage. As long as they are old enough, they start flowering as soon as there is some growth. This tells you they need a little bit of growth to produce flowers. Plants that grow like this we say f”lowers on current season wood”.

Can you see why oleander, Texas sage or star jasmine shouldn’t be pruned during the summer? Instead, they are best pruned during the winter when spring and summer growth provides the new “stem growth” needed for producing flowers. If these plants are pruned just before or after they start their new growth in the spring, it causes their flowering to “pause” until there is some new growth.

Imidacloprid, Insecticides and Safety

Q. I don't like what I'm reading about Imidacloprid (frequently found in borer control insecticides) and wanted to know if there is a better insecticide that won't harm bees.

Bayers Tree and Shrub Insect Control insecticide is one of many insecticides approved by the USEPA for killing some borers, like Emerald Ash Borer (not currently found in Nevada). 

A. You are talking about an ingredient (tiny letters on the label under active ingredients) found in several different products rather than an actual product name (big letters) found on the label. The actual or product name might be “Merit” for commercial applicators and “Bayer Tree and Shrub Spray” for homeowners but also many others

Some Countries Banned It

As a "class" of insecticides, the neonicotinoids are the most used group of manufactured insecticides in the world. Insecticides containing imidcloprid have been banned for use in some countries due to accumulated evidence. That particular ingredient is still approved for use in the United States but has faced a lot of environmental problems and may be eliminated in the future. It has been implicated in the death of some pollinators like honeybees when visiting the pollen contained in open flowers.

How to Apply it Safely

The label information for these types of products gives you a clue about how to apply it properly. If you must use this product, apply it to plants after they have finished flowering. This helps prevent the transmission of this ingredient to pollinators.

Alternatives

At this particular time I don’t know of any insecticide available or permitted for use that has the same potential for controlling borers as imidacloprid. Its major advantage is also, potentially, its disadvantage; it is a long-lived systemic insecticide that can potentially be harbored in flowers, fruit produced and plant parts for up to 12 months. The only other option I know that can work is the digging of these problem insects from infested trees as they are seen.

 

Borers can be removed from an infested limb with a sharp, sanitized knife.

Drawback to Woodchips: They do attract vermin

Q. My backyard has several planting beds containing roses, rosemary, mock orange, euonymus, pyracantha, lantana, sago palms, and other plants. I added rock to the soil surface eight years ago and these plants started to decline in about five years. I decided to remove the rock and put woodchips down instead but afraid of roaches entering the house from the woodchips.

Irrigation valve box amongst plants receiving water. When you combine woodchips, water and a valve box it is normal for cockroaches and spiders to live and enter there. Spray the inside of these boxes with an insecticide once a year to help reduce these numbers. But this will not stop them from helping to decompose the woodhips.

A. Insects such as cockroaches like water and something to eat. They live in the woodchips exposed to water because they help break down debris from the wood chips. Cockroaches, unpleasant as they are, are decomposers. Their favorite place to congregate in the landscape is in irrigation boxes where it stays wet. They are attracted to these wet areas and warmth of your home when it gets cold so they may come inside as their populations get larger.

Keep landscape areas close to the home dry. Apply water to landscape plants no closer than 3 feet from your house exterior walls. There isn’t a good reason to apply water closer than this. In a desert climate where there is limited rainfall, plant roots follow irrigation water. Irrigating foundation plants on the side away from the home causes their roots to grow in that direction. Keeping the soil dry surrounding your home also reduces water damage to the cement as well as reducing insect problems inside the home.

After removing the rock and before you apply woodchips, sprinkle the wet areas around plants with a rich compost to help feed the plants, enrich the soil, and start the decomposition process.