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Friday, December 21, 2012

Nothing Wrong With Slight Yellowing of Mid Pride Peach Tree

Mid Pride peach with yellowing leaves
Q. Could you tell what is the problem with my mid pride peach tree? I sent you pictures.

A. You have a great selection in a mid-pride peach. Honestly, I don't see a whole lot wrong with it. The leaves are yellowish but this is not due to iron. This is actually some sunburn and discoloration to the leaves.

            The difference between iron and bleaching by intense sunlight is in the coloration of the leaf. When a leaf is discolored due to high light intensities or sunburn they tend to bronze in there yellowing. This bronzing is over the entire leaf.

            Yellowing due to a lack of available iron in the beginning stages of the leaf’s growth causes the yellowing to occur between the veins of the leaf, leaving the veins a darker green color. The term for this is in interveinal (between the veins) chlorosis (yellowing).

Closeup of the leaves on this Mid Pride peach
            As the lack of iron intensifies, the yellowing between the veins becomes more pronounced. As the iron problem worsens more, the leaf begins to scorch around the edges (it is unhealthy and cannot handle stress as well) and the interveinal chlorosis progressively gets worse. At some time, and in some species, the entire leaf may become totally yellow with scorching on the leaf margins and the veins only with a hint of green in them.

          The best type of iron chelate for us is also the most expensive one. But a little bit can go a long way. The only place I have seen this for sale in retail packages in small homeowner quantities (one pound) has been at Plant World Nursery in Las Vegas.

Whats Wrong With My Eastern Redbud Tree?

Q. Could you tell what is the problem with my eastern red bud tree? I sent you pictures.

Leaf damage to Eastern redbud growing in southern Nevada.
Eastern redbud is an understory tree in the eastern US
and does not handle harsh environments well
A. The redbud problem is pretty common with this tree and our soils and climate. Western Redbud is more tolerant than the Eastern Redbud of our conditions and would be a preferred tree for the Western United States.

            Western redbud may not be easy to find in the nurseries but it is worth a look. Another tree that might be even a better selection for you would be the Mexican redbud which looks very similar and would give you a similar impact to the Eastern redbud.

            The problem you are seeing on the leaves, scorching and discoloration, will always be a problem in this climate and soils with that tree. Eastern redbud is an understory tree in the eastern part of the United States which means it does not handle full sun very well even in the cooler parts of this country. Think of the problems it will have in our desert climate, high light intensity and alkaline soils.

            I usually encourage people to try something new but this is a small tree that you would have to babysit for many years to come even if you've found the right spot for it. I would encourage you to look for the Mexican Redbud if this is going into a desert or rock type landscape.

See what a Mexican redbud looks like

Be Careful Pruning Ash Trees

The tree on the right is ash and on the left is mulberry. The
mulberry has the ability to come back after severe pruning
due to some "hidden buds" or what can call
undifferentiated tissue that can regenerate new growth
while the ash does not and will frequently severely die back.
Q. We have two fantex ash trees that are 15 years old. They are spreading out too far. How far can we cut them back without killing them?

A. The problem with ash is that it does not have much ability to come back from cut limbs if you cut back too far and into larger wood. You should begin to structure the tree fairly early and stay on top of it but if you let it go too long and then cut it back you may have some problems.

            You can cut it back to side branches that are growing in a desirable direction but you cannot prune it back by what we call heading cuts (stubbing it back) and hoping these dead end cuts will resprout. You can cut back into second or maybe three year old wood (there are still side buds remaining that can grow) but if you cut into a limb with no buds present, it will probably die back to a major limb.

Thinning  cut, removal of an entire limb, on
a peach tree.
            So cut a branch to a crotch going in the direction you want the limbs coming from that crotch to grow. If a limb is a problem, remove the entire limb back to its source. Do not leave any stubs (dead end cuts).

            I hope this makes sense. I will put on my blog a picture of a thinning cut made removing a larger limb.

Softened Water Can Be A Problem for Landscapes and Houseplants

Salt damage to guava from saline or salty
water in the overhead irrigation (water
applied to the leaves)
Q. I'd like to soften the water in our house, or at least get some of the minerals out of the pipes. Culligan-type water softeners are supposed to release a lot of salt into the ground, which I think is harmful for the plants.  You can separate your softened water from your water for the plants but I've heard that is not cheap.  There are other so-called softeners which use calcium or potassium chloride or something else besides salt in the Culligan-type units but it's more expensive.  What should I do?

A. I am not going to talk about the pros and cons of water softened with sodium chloride versus potassium chloride for personal use. This is not my area of expertise but I can speak the subject of watering plants with softened water and your irrigation system.

            Normally, softened water starts after the water from the street has been tapped for your irrigation system. If this is done, it should not be a problem for you. It most likely would be a problem if you have tapped an irrigation system from a hose bib coming from the walls of your house. Many houses have their water softener conditioning water going to every water outlet in the entire inside of the house.
Salt applied to the ground from saline water applied through
drip emitters
            This will mean that softened water is delivered to both hot and cold faucets as well as the hose bibs you use for hoses outside the house. So if you have a water softener and you have some sort of irrigation system attached to a hose bib, then you are most likely watering outside plants with softened or saline water.

            Whenever you use a hose attached to a faucet coming from the walls of your house, then it will be carrying softened water. If you are watering houseplants from an inside faucet and you have softened water, then you are most likely watering them with softened water.

Salt damage to rose leaves from soil salts, not applied to the
leaves through overhead irrigation but salt in the soil
            Is softened water bad? Yes, it can be. If you are using inexpensive water softening salts then this is most likely sodium chloride or common table salt. Sodium is very toxic to plants and can destroy the structure of soils. Chlorides are essential to plants but in high amounts it can also be toxic.

            What to do? As you mentioned, potassium chloride is an alternative water softening salt to regular water softening salt but it is more expensive. In fact, it can be double the price or more. Potassium is a mineral contained in fertilizers and used by plants in fairly high quantities. So potassium chloride would be a better alternative for plants than common water softening salt.
Pitting of the sidewalk from water runoff
from the lawn of water containing salts

            When I installed my irrigation system, I put hose bibs in the landscape that were fed by the pressurized main line of the irrigation system. This way when I watered with a hose I was not using softened water. I avoided using water from hose bibs coming from the house.

            When I watered houseplants, I use distilled or RO water instead of water from the faucets. I mixed a very small amount of houseplant fertilizer in the water so that it had some good minerals in it. This avoided the use of softened water on houseplants which can be very toxic to most of them.