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Thursday, April 30, 2015

Get Rid of Springtails by Mopping Up

Q. I was told by the Nevada Department of Agriculture the tiny insect I found jumping around in my bathroom were springtails. I have read they are very hard to kill which I finding out after I had an exterminator try to get rid of them.

A. Insecticides are not a good choice for controlling springtails. It usually requires several repeat applications of traditional household insecticides and they will return if the source of the problem is not corrected.

What are springtails?

Springtails are tiny jumping insects, about 1/16 inch long, that are found in cooler times of the year where there is standing water. I have seen them here outside in grass that is kept too wet or where there is a water leak.

Because they are such good jumpers they are sometimes confused with leafhoppers outside the home and fleas inside the home. They are neither.

Inside the house they can multiply where the flooring is kept constantly moist. They feed live off of mold and fungi that grow where there is shallow, standing water or very wet soils. If the area is kept dry and cleaned up they will disappear.

Save your money. Don’t apply pesticides. Fix the area so it stays dry and sanitize it.

Prevent Roaches from Mulches Entering the Home

Q. I know you recommend bark mulches around trees to help in water retention. However, there are negatives to consider such as cockroaches, bugs, etc.  I encounter lots of cockroaches in the ground when I have excavated in certain areas of our yard.

Untreated wood chip mulch including pine needles and leaves
A. I encourage the use of wood mulches more than bark mulches. Bark mulches seldom decompose much and add very little value to the soil. They are purely decorative. Wood mulches decompose easily in moist soils and add a lot of value to desert soils.

Benefits of wood chip mulch

You are absolutely right. Insects such as cockroaches are scavengers. Like many insects they like two things; water and a food source. This is why you frequently see tons of them inside irrigation boxes.

They feed on plants and animal life that have died and help in its decomposition. Feeding on dead and animal life helps return organic life back to the soil.

Cockroaches do not discriminate between dead plant or animal life whether it is inside the home or outside the home. They will enter the home if given the opportunity.

Using a foundation spray

Using a foundation spray or pesticide around the perimeter of the home and in valve boxes helps to keep them from entering our home. This is an insecticide spray barrier applied to the outside of the home at soil level and 12 inches above the soil. A good time to make this application is when temperatures begin to cool in the fall.

 It also helps if you keep wood mulches away from the foundation of the home. There is no reason you need to apply wood mulches up to the foundation.

Pruning Fruit Trees in Late Spring

Q. I have added some fruit trees such as Asian pear, peach and apricot to my yard. When is the best time for pruning these trees?

A. The pruning of fruit trees is done for two separate reasons; establishing the architecture or structure of the tree and encourage the production of high quality fruit. There is even a third reason that is not talked about very often and that is helping to keep trees smaller.
Winter pruning establishes the architecture of the tree. The most productive branches are at 45° angles.

Prune at the Time of Planting. When purchasing a tree and its structure needs improvement, you should prune for improved structure immediately after planting and not wait until the end of the growing season.

Prune in Winter Months. With established trees, major improvements to the architecture of an established tree that require a pruning saw or loppers should be done in the winter months. For deciduous fruit trees, it is much easier to see the architecture of the tree when the leaves are gone. Smaller changes in its structure requiring a hand pruners could be done anytime.

Summer Pruning. I encourage summer pruning during the month of April and early May in our climate. Summer pruning focuses on removing aggressive vertical growth that has grown since spring. Sometimes we refer to this growth as “suckers” or “watersprouts”.
Strong vertical growth can be removed very early in the season by pulling downward. This is called summer pruning and helps to reduce interior shading of the tree and improves fruit quality and production. It also helps to dwarf a tree by robbing it of its new growth.
Summer pruning is used to reduce the interior shading of fruit trees which decreases production and helps keep the size of fruit trees smaller. It is also used to take away the future growth potential of a tree. When a tree is pushing new growth it is making an investment in the future. The tree is using stored food reserves for pushing new growth. That tree will recover the food reserves it used and more after its new growth has matured.

Strong vertical growth is seldom fruitful in the short run. Strong vertical growth is used by the tree to gain height. This type of growth should be removed and is easy to do. Pulling downward on immature watersprouts will remove them cleanly and efficiently without using a pruning shears. If you wait too long this growth can no longer be removed by pulling. It must be cut off. This leaves stubs that will sprout in the future.

Raggedy Roses Probably Damage from Thrips

Q. My yellow roses were beautiful the first time they bloomed before Easter. However, the flowers aren’t pretty any more after they open. The flower looks burned on the edges of the petals. I haven't seen bugs on the flowers. Otherwise the plant looks healthy to me.

A. Your roses, from the sound of it, are probably infested with Western flower thrips. These are very small insects that are nearly impossible to see unless you use a magnifying glass and inspect the flowers very closely. They are also difficult to control.

Posting in pictures by Colorado MasterGardeners
Thrips damage on lots of things in Canada

Thrips are poor fliers and so stay close to the plants they feed upon. They have mouthparts that shred tender plant parts such as flower petals and flower buds before or after they open. The flower petals appear damaged and with streaks of brown.

Soap and water sprays are somewhat effective but the best to spray for controlling this insect contains Spinosad.

Dormant sprays of horticultural oil during the winter and applied before the plants start growing will also help. I would alternate sprays between an insecticidal soap such as Safer's and Spinosad sprays until you get some control.

How to Grow Moringa in the Las Vegas Valley

Q. I planted a Moringa tree for its health benefits. I understand it is native to the tropics. Can you tell me how to grow it in this climate?

A. You know that Moringa will be killed back to the ground every time we have a hard freeze. For this reason, we have to manage it similar to bougainvillea. Moringa grows on its own roots so we don’t have to worry about suckers developing from a rootstock like we do with most tender citrus.

Moringa is one of those plants touted for its health benefits. It is native to tropical and subtropical South Asia and has spread to Africa, South East Asia and more recently Latin America where the leaves and pods are used in cooking. Most recently it has been labeled a “superfood” by the media.

Moringa is also called the horseradish tree, drumstick tree or malungay. It will grow here but it has to be managed differently than in the tropics. Establishment of the tree by cuttings or trunk cuttings is quite common in the tropics. Establishment in our desert soils is similar to any fruit tree by using compost to amend the soil during the time of planting. This is a tree I would mulch with wood chips, not rock mulch.

Marine got can be started from seed very easily. Start them the same way you would start tomato seeds or any other tropical seed. They require warmth, above 70° F moisture and good drainage. Start them as early in the season as possible so that you get enough growth on them before you put them out.

Growth rates of this tree are extremely rapid and you can expect 6 or more feet of growth during the first year if it’s given enough water. This is a large tree in the wild and it will want to have one central trunk.

You should discourage this central trunk by cutting it close to the ground after it gets about 2 to 3 feet tall. This pruning cut will encourage suckering from the base of the tree which is what you want. You should probably grow it as a shrub, not a tree in our climate.

Let it get damaged in the first light freeze of the winter. After the freeze has passed, cut the plant to the ground and protect it during very cold weather.

You can do this by throwing a blanket over it and preventing the blanket from blowing away during high winds. Remove the blanket during warm daytime temperatures. Fertilize it with your favorite high nitrogen fertilizer that promotes leaf and stem growth. 

How to Move a Joshua Tree

Q. I am lucky to have a Joshua tree that is about 3ft tall and I am thinking about moving it now that it has been five or six years in the ground. Am I going to be successful in moving it or do you think I will kill it?

Joshua tree that was planted and still small enough
 to move without much difficulty.
A. Joshua trees are difficult to move from the wild but much easier when it has been planted once and watered with drip irrigation. It should move okay.

Your major precautions are to make sure its new home drains water easily and not to overwater it after planting. I would avoid moving it when it is hot but you could move it now during the spring or fall months.

Dig the hole where it will be planted ahead of time. Fill this hole with water and make sure it drains in a few hours. Amend the soil taken from the hole with about 25% compost and use it for backfilling the hole after planting.

Add a handful or two of a high phosphorus fertilizer to this soil mix to encourage rooting. It will be important to stake the tree the first season after planting to keep the roots from moving during establishment.

Take as much of the root system as possible when you move it to its new home. There will be far less shock to the plant and better establishment if the roots are disturbed as little as possible.

Moving a much larger Joshua tree with very little root system.
Most of the roots will be close to the drip emitters or source of water and within about 12 inches of
the soil surface. When you move it, take as much of the soil around the roots as possible and plant it with this “root ball”.

Make a mental note of the north side of the tree. Orient it the same direction as it was previously. Stake it after planting for one growing season.

Do not water too often. You can overwater it by giving it more water in a single watering but do not give it water more than every three weeks.

Late Application of Iron Fails to Cure Yellowing

Kerex iron application made to the soil after growth has already begun will result in yellow leaves on the older leaves while the new leaves coming out after the application will be green.

Q. I have a Burgundy plum tree that is 3 years old. The leaves became yellow in March so I applied Kerex iron to the soil when I first noticed the problem. Now the new leaves do not show any yellow in them but older leaves are still yellow so I do not think it is an iron problem.

A. Iron does not move once inside the plant. It is still an iron issue. You said the NEW leaves do not show any yellow. That means your KeRex application in March worked for the leaves which grew after your application.

Iron does not move around inside the tree once the plant takes it up, it only goes into the new growth after the application is made.We say that iron is immobile once inside the plant. It is not like nitrogen which can move from older leaves to newer leaves. Iron cannot do this. Iron can only be transported into new growth. Growth before the application will still stay yellow.

Correcting the problem. The only way to correct yellow of older leaves is with iron spray applied to the leaves. This is why SOIL applications of iron are so important to make in January before growth occurs.

An example of an iron product that can be used for foliar applications, or sprayed on the leaves. Spraying the leaves with an iron solution is the only way to correct yellowing once it is already started. Make sure you use a wetting agent mixed with the iron spray.
EZ Wet is one example of a high quality wetting agent that does not contain
any personal care products and made entirely from yucca extract.
It is not too hot too late to spray iron on the leaves. It may take four or five sprays a couple of days apart to get all the yellow leaves completely green.

Any iron product, labeled as a spray applied to the foliage of fruit trees will work. However, I would strongly suggest that any water mixed with this iron fertilizer should be distilled water so that the pH is close to neutral (pH of 7).

Alternatively, you can adjust the tap water close to neutral using vinegar or another mild acid as well.

You should add a wetting agent to the spray as well. This helps the iron penetrate the leaf surface and enter the inside the leaf. Otherwise the spray is not as effective. Some people use liquid detergents with good success. I worry a little bit about the other personal care products in liquid detergents so I would encourage you to use a commercial wetting agent.

If you are still unsure how to do this, you can read more about how to do this on my blog or email me at extremehort@aol.com

Fertilizer Injectors Have Advantages and Disadvantages

Q. I know of fertilizer systems which friends have linked to their home yard watering systems. These can be adjusted as to the quantity of fertilizer added to the water. However, it seems this might be quite a bit of fertilizer applied to the plants. Yet, a neighbor is very enthusiastic about the benefits. Can you advise me on this subject?

Simple fertilizer injector using a stock tank of a fertilizer dissolved in water. Here we are preparing the stock solution to be injected into the irrigation line using the Venturi effect. In Kosovo.
A. These fertilizer systems have different methods of injecting fertilizer into the water. They range in different prices based upon how precise they can deliver fertilizer. Collectively we call them fertilizer injectors. They can be adjusted so they deliver a very tiny amount of fertilizer or deliver a lot of fertilizer at one time and then turned off until needed again.

The fertilizer was injected into the irrigation line and was applied with overhead drip irrigation using micro sprays. This is seedling production in a greenhouse in Kosovo. Benches were created using bales of straw.
Background. Fertilizer injectors were designed primarily for agriculture and commercial horticulture use where one type of plant is grown or plants grown with similar water and fertilizer requirements. Their primary purpose was to save the cost in applying fertilizer.

Several types of injectors are available for home landscapes in a range of prices. The primary difference in these injectors is their level of precision. Most inexpensive homeowner fertilizer injectors operate on the "venturi effect". The venturi effect pulls a concentrated fertilizer solution from a bucket or small tank into a stream of water. This stream of water might be in a hose or an irrigation line. The principle of the venturi effect  is used in some automated pool cleaners, wine aerators, recoilless rifles and in the pressure regulator for scuba gear.

You can watch how the Venturi effect works in irrigation lines in this video from Jain Irrigation

The venturi effect causes concentrated fertilizer solution to mix into the stream of irrigation water. You can operate your injector to apply fertilizer continuously or periodically on a fixed schedule; once a month; once every three months, spring and summer, etc. If you put fertilizer in the injector, it will fertilize. If you don't, it won't.

Advantages and Disadvantages. The primary advantage to the homeowner is less labor which saves time. Some may argue it also saves the homeowner money and the landscape looks better. Both are arguable but I don’t think anyone can argue it is not a timesaver. I will go into more detail on my blog.

The primary disadvantage for homeowners is that all plants which receive water at the same time also receive the same kind of fertilizer. When fertilizing plants by hand, you have the option of giving them different types of fertilizers, not all the same kind.

Plants which receive more water also receive more fertilizer and the reverse is true. The application of fertilizer in precise amounts should also require a very efficient irrigation system. These go hand in hand.

In short, make your decision based upon the saving of time and labor. All of the other points are arguable and may or may not apply. 

Operating Your System. Leaving water with fertilizer in it in your irrigation lines for more than a few days can lead to algal, fungal and bacterial growth. It is best to apply fertilizer and allow fresh water to clean the irrigation lines after the fertilizer has been applied. Make sure there is a screen filter downstream of your fertilizer injector to prevent plugging of your drip emitters.

Monday, April 27, 2015

New Product for Lowering Soil Alkalinity (pH)

This was a very interesting product. When a few ounces were mixed with tap water it dropped the pH of the water to 3.1. We do not have that many good options for lowering soil pH. The sulfur we get now is coarse and takes years to break down.This product breaks down quickly with applied water. It gets me wondering about our acid-loving plants like azaleas, rhododendrons, hydraneas, camelias and the like. I also wondered about southern highbush blueberries and their potential here if we could find a suitable product to lower soil pH. It might also help plants that struggle with iron problems like photinia, bottlebrush and mock orange. It might be worth a try!

Viragrow Delivers! : New Product for Lowering Soil Alkalinity (pH): Have you wanted to grow southern highbush blueberries in the Mojave desert but the soil pH was too high? How about azaleas and rhododendron...