Dieback of Mature Fan Tex Ash

Q. I was cleaning up the leaves from my Fan-Tex Ash tree and noticed that there was sap leaking from 4 different limbs of the tree.  Attached are some pictures.  The tree is about 18 years old.  Although the first picture shows a small number of leaves remaining, the tree has always has had a nice canopy of leaves including this past year.   The tree is in rock much, but it receives nutrients (24-8-16) from an in-line liquid fertilization system.

Readers Fan Tex ash tree

I did some on-line research and the sap could be caused by stress (not enough water) or some type of borer.  The tree receives about 30 gallons of water each time it is watered.  In the winter it is watered once a week, spring and fall twice a week, and in the summer 3 times a week.  Is it common for this tree to have borers or is this problem likely caused by insufficient water?

A. The amount of water it is receiving sounds about right or possibly a little bit on the light side. It is definitely not being over watered. Your frequency of application also sounds about right seasonally. If this tree is surrounded by rock mulch then the amount of water applied may not be enough.

Look at New Growth

Look at how much new growth occurs every year. At eighteen years of age the tree is in youthful maturity. The tree should be growing at least 8 to 12 inches minimum every year of new growth. If new growth is less than 8 inches every year then there is a problem.

You are right in several things. It could be damage from borers. It could also be from stress such as a lack of water.

Ash Decline Disease

Fan Tex ash is an Arizona ash. Arizona ash has a problem with ash decline disease. For this reason, I no longer recommend planting any of the Arizona ash trees including Fan Tex. The tops of the trees could have developed ash decline even though this look is not typical of ash decline. 

Ash decline usually hits one or two branches at a time and causes dieback and slow growth and leaves scorching. It is also possible it has sooty canker disease. Borers are usually associated with sunburn of limbs lower in the canopy. If this tree were topped with a chainsaw it is possible that any of these three possibilities could be a problem.

Dieback of ash due to Ash Decline

A severe case of ash decline on Modesto ash

If this is ash decline disease, the tree is a goner and it will continue to slowly decline in coming years. I would recommend that it would be removed. If this is borers or sooty canker disease then some pruning might help it recover. If you decide to keep this tree, I would have a qualified arborist selectively remove the damaged parts of this tree. Certified arborists know how to prune trees and improve their ornamental value.

Fertilizer Injector

It is nice to know that these trees are getting part of what they need through an injection system that deliverables mineral fertilizers.

Rock Mulch

This is only a partial solution to successfully growing ornamental trees in desert soils. If these soils are covered in rock mulch then the soil is probably low in organic content. The organic content can be very important to ornamental trees growing in desert soils. Rock mulch causes desert soils to slowly become less and less organic over the years. Mineral fertilizers will not solve this problem. Either covering the soil with woodchip mulch that decomposes or continually adding compost to the soil will work. As this soil becomes more “mineralized” over time the tree may continually decline.

If the soil is covered in rock mulch, add compost to the top of the soil and water it in. You would do this once a year for the next three or four years but it is a slow soil improvement process. This is all hinged on whether you have rock mulch or not. The faster option is to make vertical holes with post hole diggers throughout the root area of the tree and backfill these vertical holes with compost. This gets the compost mixed into the soil much faster and produces faster results.

If this turns out to be borers than applications of systemic insecticides may be her only solution to the problem. In any case, someone needs to make a decision about what the problem is which determines the course of action.

Some Compost Can Be Used as a Fertilizer

Q. If I make my own compost, can I use it instead of commercial fertilizers for grass, plants, trees, shrubs?

Some composts, if they are rich enough in nutrients, can be used like a fertilizer.

A. Yes you can. But please be aware that homemade compost is not consistent in fertilizer content and quality. This is because of variability of different nutrients in ingredients used to make the compost. However, compost is universally good, whether it’s commercial or homemade, when added to soils as a soil amendment.

This is the fertilizer content of a compost supplied by a company I consult with. This particular compost contains a large amount of fertilizer for each cubic yard of compost. This compost would make an excellent fertilizer for plants. Other composts may not contain as much fertilizer as this one.

            When using compost as a substitute for fertilizer, it is important to know its carbon to nitrogen ratio, in other words how much nitrogen fertilizer it contains. The nitrogen content of a compost is critical. High nitrogen content (low carbon to nitrogen ratio) makes compost “hot” and less of it should be used. If compost has a high carbon to nitrogen ratio (low nitrogen content), then more of it should be applied when substituting it for fertilizer

When applying compost as a fertilizer for plants, it is important to keep the fertilizer away from the trunk of trees and the stems of soft, succulent plants. This type of application is okay for woody plants but vegetables and annual flowers should have the compost mixed with the soil before planting because of the high salt content from the fertilizer salts.

            Commercial composts aim for a carbon to nitrogen ratio close to 20:1 or twenty times more carbon than nitrogen. As this ratio increases to 40:1, the nitrogen fertilizer content decreases. At a ratio more than 40:1, the compost is still valuable but it’s value is greater as a soil amendment rather than fertilizer.

            The carbon to nitrogen ratio in homemade compost is managed through what is added to the compost mix before composting. “Woody” additions to compost like wood chips, sawdust and shredded newspaper (sometimes referred to as the “brown” component) increase the carbon to nitrogen ratio.

            Additions of grass clippings, leaves of trees and shrubs, and vegetable scraps (referred to as the “green” component) lowers the carbon to nitrogen ratio and make it more valuable as a fertilizer.

            Animal manure (think of it as a concentrated “green” component) is high in nitrogen and added to get the carbon to nitrogen ratio low and improve fertilizer content. If lots of different components are mixed together in the right proportions, green components are balanced with brown components, homemade compost has all the nutrients needed by plants.

            The short answer is “yes”. But substituting a homemade compost for a fertilizer application varies from batch to batch depending on what was used to make the compost.

Organic Soil Amendments at Planting vs No Organic Amendments

Q.  I’m planting new fruit trees and landscape trees this year. I noticed there is a consensus out there that fruit trees, trees and shrubs should be backfilled with native soil without using any amendments. However, is there an exception in Las Vegas with the soil is exceptionally poor?

Typical "native" or "natural" desert soil in Las Vegas. Would you plant directly in this? I hope not.

Here is the SAME soil (25 feet away) ten years later after wood chips were spread on the soil surface and water was applied for fruit trees. Now which soil would plants be "happier" growing in?

A. You are right and my advice is bucking conventional advice from most places. For instance, using native soil for backfill in North Carolina will be fine in most cases. But it also depends on what is planted. Many urban landscapes have "fill" that was brought in by the developer or general contractor. Most fill...No, I take that back...ALL fill... used in urban desert settings is junk. Using soil amendments depends on the soil and also the plants. Let me explain why.

Desert Soils Vary in Organic Content

            Some desert soils are okay to plant into directly and you will have few problems. Others are not. Much of it depends on the organic matter content of the soil and the type of plants. If your soil contains at least 5% organic matter at the time of planting, the addition of organics to the soil as a soil amendment probably won't do much. If the plants going into the soil prefer growing in highly organic soils, you are probably going to see a problem if the organic content is only 5%.For instance, a soil with low organic content but suitable for lawn grasses or some trees and shrubs will not be suitable for annual flowers or vegetables.

 Soils are a Mixture of Sand, Silt, Clay AND Organics

            Soils are a mixture of minerals and organic content that results from dead plants and animals that decompose into the soil. Desert soils with very low rainfall like ours.

This is a jar test. I have students do this to their soils at home. First of all, the soil is darker in color which means it has organics in it unless it is a soil like a Latersol in the tropics. This is NOT a desert soil. I can tell from the color. The organic component has mixed in with the soil particles and colored it darker but the larger stuff either floats on the surface or is the very top layer on top of the clay layer.

            When planting without soil amendments such as compost, soil organic matter content should be at least 5% if you don't want the plants to be "unhealthy". If it is lower than this, add organic content to the soil such as a good quality compost. Mix it with the soil taken from the planting hole.

            Another option is to use a soil mix for filling the planting hole around the tree roots or container roots. Soil mixes are like Hamburger Helper; they contain organics and it is convenient and easier to use than mixing the soil yourself.

Soil color can tell you alot about a soil. This cark soil color tells me there is a good amount of organics in it and will not need to be amended for lawns and some trees and shrubs.

            Be careful of adding too much organic content to the soil. This can work against the establishment of the plant in the surrounding soil. This is the situation with research done in Oklahoma, Arizona and other states. These practices of “not adding organic matter” to the soil at planting is from their research with soils already high enough in organic matter to make little difference after platning.

This is the same desert soil you saw above. Organics are added to this desert soil AND the soil is covered in wood chips to add organics to the soil over time as long as there is rain or irrigation.

Many soils of the Mojave Desert with very low rainfall are extremely low in organics. Soils in the desert that are relatively high in rainfall or were previously farm land (under irrigation). These are usually already high enough in organics and adding more does little, if any, good. Using the deserts of the Southwest as an example (Sonoran, Mojave, Chihuhuan, Great Basin) they range in historical rainfall from 4 inches to over 10 inches of rainfall each year. This is a 250% difference depending on locale!!! Of course we will see different types of plants and a difference in plant density and canopy size when we compare desert environments with a difference in rainfall of 250%!!! This is reflected in soil differences there as well. We see differences in organic content, salts, pH, etc.

Map of the US showing organic content of soils and how it varies with rainfall. Desert soils are always lower in soil organics than soils in wetter climates unless they are amended.

How Do You Know the Organic Content of a Soil?

We can send it to a soil testing laboratory and spend maybe $75 to $100 and wait for three weeks for a reply or use our noggin and get a rough approximation. The soil testing lab will give you a precise amount in the sample sent to them. If the sample sent to them is representative of the soil that interests us, then it may be fairly accurate. But, garbage in, garbage out. If the sample is NOT a good representation of the soil that interests us then it is garbage.

Look at the soil

Soil color is a pretty good indicator of soil organic content. Rich soils, full of organics are brown to black. The lighter the color, the less organics in it. If the soil is moist and dark brown, you probably don’t have to add anything. If it is light tan or very light colored, even when moist, it probably needs organics added despite the recommendations from Oklahoma or Arizona.

Dig in the soil

If you need a pick to dig or a shovel barely scrapes the surface, AND it is light colored….ADD ORGANICS!!!! Add organics in a ratio of about 1:1 by volume or container. Add a five gallon bucket of compost to this cement-like soil. Adding organics/compost in a 1:1 ratio (v/v) will NOT result in 50% organic matter content but probably in about 3 to 5% content after watering, settling, and growing for one season. 

Next year add 25% by volume (v/v) if it is a garden soil or apply about one inch of compost to the soil surface around a plant and lightly scratch it into the soil surface, and water it in. Keep compost at least (approximately) 6 to 12 inches from the “trunk” or stem of the plant. Beginning the third year, add compost around the tree/plant at the beginning of its growth cycle primarily for nutrients and improved biological activity.

Las Vegas soils, most of them, are extremely low in organics. ADD compost to these soils at the time of planting. You have one time to do it and after that it is very hard to do if not done at planting.

Would You Like to Learn More?

Sign up for my half day class on the Basics of Desert Soils and Growing Horticultural Crops offered in early March 2018. Read all you want in books and the internet but this class focuses on growing plants in desert soils of the Mojave. Class size is limited. Enroll now using the link below.

https://www.eventbrite.com/e/desert-soils-and-successfully-growing-plants-in-the-desert-tickets-42010937846

Are Organic Fertilizers Really Organic?

The organic movement has a foothold in the turfgrass and ornamental industry. The same industry brewing for decades in home vegetable gardens, and then with small-scale producers, has emerged as a significant market percentage for commercial landscapers. Homeowners are asking for “organic” landscape plants, organic methods of controlling pests and applications of “organic” fertilizer to their landscapes.

Migration of Organics to the Landscape Industry

            Alternative methods for producing and maintaining ornamentals and turfgrass have been around for a long, long time. In the past, very few residential clients were willing to pay for the additional costa associated with the product. That may be changing thanks to local food movements and organic agriculture¹. The word “organic” has become synonymous with “wholesome” and “safe”.

Organic fertilizers for vegetable gardens

            Organic has a different meaning in landscape horticulture industry. Organic can mean sources that are not synthetic or conventional. Organic amendments, such as municipal and animal sources of biosolids, can be applied to improve soil physical and chemical properties which in turn can improve turfgrass establishment rates, growth, and quality. We know, for instance, that in poor or marginal soils the incorporation of compost improves soil properties, increases soil nutrients and consequently improves plant growth. In soils with a naturally higher percentage of organic matter these improvements are less noticeable.

Nitroform urea used in the landscape industry could be classified as an "organic" fertilizer even though it is manufactured

 Composted Dairy Manure Reduced Turfgrass Disease in Colorado

            Research at Colorado State University evaluated the effects of applying composted dairy manure as topdressing to Kentucky bluegrass. Researchers applied compost at the rates of 13.3, 26.6 and 40 cubic yards to the acre. Applying composted manure as topdressing to established bluegrass in 2003 through 2004 improved the soil’s physical properties and nutrient content.

EZ Green Is a composted chicken manure product for the landscape industry that is OMRI listed product for the organic program by USDA

            Although nothing new, the application rates are important. The two higher rates improved turfgrass overall quality and allowed the grass to retain color in the fall, early winter and green up faster in the spring. Not bad for a product that is not considered a fertilizer.

            During the hot summer months the two higher application rates produced about 50% more clippings. The researchers concluded that compost improves turf quality and shoot growth via its action as a slow-release fertilizer.

Lawn clippings remove from the grass and left on the curbside for dumping in landfills. These clippings are filled with valuable nutrients that could be returned to the lawn resulting in one less fertilizer application each year.

            More turfgrass clippings sound like a potential landscaper’s nightmare but there is a positive side to this “problem”.  Increased amounts of clippings in summer months helps suppress the incidence of hot weather diseases. Infected leaf blades are removed through regular mowing and mulched back into the turfgrass sward or removed from the property.

            Disease suppression by composts, composted biosolids and compost teas in vegetable crops has been documented fairly well. But research has been conducted on the suppressive effects of composts, such as biosolids, on turfgrass diseases as well, dating back 20 years or more.

Compost tea applicator used for soil applications

            This research shows promise to “organic” gardeners by reducing the application of fungicides, synthetic fertilizers and other chemicals to home lawns. Composts show promise in controlling turf diseases such as Pythium, summer patch, brown spot, dollar spot, red thread, necrotic ring spot and others.  Reductions in the applications of pesticides such as fungicides, directly supports the “organic” movement whether it is truly organic or not.

Lawn clippings from commercial properties represent a huge amount of fertilizer that is removed from the lawn grasses and buried in landfills.

Composted Biosolids Benefits To Landscapes Shown by Texas Researchers

            Researchers at Texas A and M University, from 2005 through 2008, demonstrated the benefits from composts used for soil improvement and nutrient enrichment can be transferred from the sod farm to newly established landscapes. Previous studies with sod that recycled manure-based soil amendments as topdressing indicates that 77% of the phosphorus and 47% of the nitrogen might be removed and transported in a single sod harvest.

            About one quarter of the cubic yard of composted biosolids was incorporated to rootzone depth in a cubic yard of native soil when establishing Tifway bermudagrass sod. Researchers measured that five times more nitrogen and seven times more phosphorus was available to turfgrass grown in biosolids compared to grass grown without biosolids.

Fertilizer content of composted biosolid product by a local Las Vegas supplier

            After two sod harvests, all of the nitrogen and phosphorus applied from the biosolids was removed with the sod. These nutrients were transferred, with the sod, to the landscape.

            Although not demonstrated, researchers claimed that this could result in faster establishment times and better turfgrass cover in a shorter period of time. This, of course, would reduce the amount of fertilizers needed during sod establishment. Another coup for the organic movement.

            They also found that sod established with biosolids was lighter in weight than sod grown without biosolids. Biosolids-grown sod contained more water but less native soil than sod without biosolids. This helped preserve the native soil. Less fuel is needed for transporting the sod. Organics, are you listening?

Composts Release Fertilizer Nutrients Slowly

            Composts, when used as a fertilizer, releases nutrients slowly, acting like a slow-release fertilizer. When establishing turfgrass in sod farm operations, rapid turfgrass establishment is important so a rapid release of nutrients, particularly nitrogen, is needed.

            This was not going to happen with compost-amended soils. So the researchers applied either 50 or 100 pounds of nitrogen per acre at the time of sprigging (establishment) to supplement the slowly-released nutrients contained in the compost.

            Because of the application of supplemental nitrogen, the time between harvests in biosolids-amended soil plus fertilizer was reduced 60% compared to the time needed for sod grown with biosolids only.

            Similarly, other researchers reported better turf coverage and density when a two to three inch depth of compost was incorporated to a 6 inch soil depth compared to soil without compost. They attributed these responses to improvements in the soil’s physical properties such as better pore spaces, greater rooting depth and improved drainage.

Applying Too Much Compost Two Landscapes Can Be a Bad Thing

            Composts can be over-applied to landscapes. This can become a serious environmental concern to surface waters such as irrigation ponds and waterways. When composts high in nutrients such as nitrogen are applied to turfgrass as topdressing, researchers have found a significant amount of nitrogen can be transported to these waterways.

            Incorporation of composts to a greater depth should reduce the amount of nutrients removed compared with topdressing. Incorporation of composts to greater depths should allow for less frequent applications as well which would save money. In addition, soil incorporation of biosolids should reduce the potential for runoff of nutrients after establishing in urban landscapes.

¹USDA “trademarked” the term “organic” into its National Organic Program in The Organic Foods Production Act of 1990. This federal act required USDA to develop national standards for organic products and was codified in 2000 (Code of Federal Regulations at 7 C.F.R. 205). So far, it has only been applied to food crops. http://www.ams.usda.gov/AMSv1.0/nop

Lemon Not Meyers, Remove Fruit?

Q. My lemon is not a Meyers lemon but the tree is starting to flower. I didn’t want to pick them this early because they are still getting sweeter. Does the "remove lemons before the tree flowers" rule apply to this variety as well? 

Ponderosa lemon ready to pick on the left and immature on the right. On the tree at the same time.

Rough lemon grown in Las Vegas

A. Yes it does. It applies to all fruit trees. Try thinking like a lemon tree. The reason the tree produces fruit is to reproduce. When the fruit drops to the ground, the fruit rots and releases nutrients that feed developing seedlings.

            The tree “knows” if there is fruit attached to its branches or not. It can’t see anything but there are other types of communication that trees have perfected. When the fruit has been picked, the tree “knows” the fruit is no longer there.

            The reason for picking fruit before the tree begins flowering is to send “signals” back to the tree that it no longer has fruit attached to its branches. When fruit is missing, the reproductive or flowering cycle of the tree is encouraged.

            The beginning of flowering is the beginning of the reproductive cycle. The normal flowering cycle of trees is at certain times of the year. If this time for the normal flowering cycle to begin has passed or is delayed, the tree may not flower at all or flower very lightly.

Lemon turning yellow but hasn't quite got there yet. The color change can happen faster in the presence of ethylene gas. Ripening bananas give off lots of ethylene gas and can be used to improve coloration of citrus.

            You are right. Most citrus are considered non-climacteric, or, in other words the fruit doesn’t increase in sweetness after it is picked. It is best to wait when picking lemons to improve its sweetness, but you don’t want to leave it on the tree long enough to interfere with flowering.

            Other fruit which don’t ripen or ripen little after picking include figs, grapes, pomegranates, cherries and apples. As a consumer this means the sweetness of non-climacteric fruit does not increase much, if at all, after picking.

           If citrus is left too long on the tree fruit quality is reduced because it becomes “pithy”; it starts drying out. Remove all fruit from trees before they begin their next flowering cycle.

Italian Cypress and Twisted Juniper Struggling in the Desert

Q. So, I live in the high desert of Southeastern Utah, about 4500 feet. Minimal precip. Temps up to 110 in summer and down to 20s at night in the winter. Fast draining soil, actually just sand, but I do amend some when planting to "slow the flow" and try to make it more like soil.

I have 2 Italian Cypress about 4-5 years old and 3 Hollywood Juniper about 3 years old. They were doing well up till  beginning of last year. Now something seems to be killing them from the ground up. Initially I thought maybe rabbits were eating them but I no longer think that. I have tried more water, less water, more amendments, iron, etc. Spray with Liqui-Cop after leaf fall on my fruit trees and include the conifers. The Cypress seem to be doing a bit better than the Juniper, at least there is some green growth there. The Juniper look like they are totally dried out and peeling away.

Can you tell me if it is a disease? Insects? Critters? And what I can do about it, if anything, before they die completely! Guess my question is whether you think I can save the cypress or should I just give up?

A. You live in some beautiful country.
 

Why are the lower branches of the Italian cypress missing? Was this due to rabbits? I have seen rabbits devour newly planted, small pine trees during the winter but this is the first time I have seen it on Italian cypress.

I think you have a problem with these lower branches removed from the Italian cypress. Those lower branches are needed for several reasons. First, that foliage produces energy for the tree and improves growth by providing energy for its growth. Without that foliage, new growth is going to be minimal and weak.

Secondly, the growth along the trunk is needed for proper trunk development. Branches are needed for the trunk to develop proper caliper, i.e., taper along the trunk. Without this growth, the trunk never gets strong enough to remain upright or erect. The plant will never get strong enough to remain upright.

When they are planted make sure they get a good soil amendment such as compost and not just planting amendment. If you use planting amendment, make sure you put some 16-20-0 or some type of starter fertilizer at planting time. They should be fertilized at least once a year in early spring. If in sandy soil, twice a year.

If this was rabbit damage, next time plant them with a cylinder of 1 inch hexagonal chicken wire around them to keep the rabbits from eating them. I would use 3 to 4 ft tall cylinders. Jackrabbits can reach up to nearly 3 feet when they are on their back legs. Eating foliage that high should not be a problem but lower foliage missing will be a problem.

I think you may have some sun damage to the lower trunk on the cypress from missing branches along the trunk. Check for borer damage in them as well.

Hollywood junipers are notorious for borer damage. Look close at the trunks and I am willing to bet you have them. Use Bayer Insect Control as a liquid drench around these to protect them from borer damage. Better yet, don’t plant them here. Plant something else.

 

Borers in Hollywood Twisted Juniper from 25 years ago

I think it will be okay. I would just protect it with some chicken wire if rabbits are the cause. You need to push new growth. That will be done with fertilizer and timely watering. Fertilize twice during the year, February and again in about June. Throw one or two handfuls of fertilizer about a foot from the base of the tree and sprinkled on the soil. Water it in. If you have basins, put it in the basins and water it in. Keep fertilizer away from direct contact with the trunk.

You have the self watering containers around the base. I am wondering why you are not using the drip irrigation that is there in the pictures. Italian cypress like wet winters and dry summers. Water as you would any tree during the summer. Probably twice a week during high temperatures and I would give them about 5-10 gallons when they are small each time you watered. Winter time maybe once  a week or ten days. Keep the amount of water you apply the same each time. Apply this amount of water more often as it gets warmer.