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Friday, July 29, 2016

Apricot Disease Seldom Occurs in the Desert

Q. My apricots were doing very well as they have for the last several years.  After thinning a large crop this year, they were growing very well and appeared to be getting ready to pick when I opened the cots, I found the insides to be rotting.  I've tried to do a little research without success. 

A. This may be ripe fruit rot, sometimes called Brown fruit rot. It can happen if there is rain near the time of harvest. We get other diseases on fruit as well if there are rainy periods at different stages of fruit development.
            There is not much you can do except hope that rain does not occur at that time. Here is some information from the University of California. See if this description matches your problem.

They recommend fungicide applications earlier in the season to present it but we get such a little chance of rain here to me it doesn't make any sense to make these applications. Just figure this year you had some losses that come along very infrequently.

Citrus Help For the Land of Ice and Snow

Q. I live in Michigan, so our experience with citrus is non-existent, and there are no experts in our area, but you come recommended as someone who might be able to give me some advice. 
I have a small potted orange tree with a few leaves that have turned light colored along the edges.  They aren’t yellow or brittle as one might expect in the case of iron deficiency, but are shiny and flexible like the rest of the leaves.

I bought the tree on a lark, never expecting it to survive, but it thrives except for these few leaves.

The plant is outside, on the east side of the house when the temperatures will stay about 40ºF.  The rest of the time (about 7 months a year) it is inside, on an east facing but brightly lit porch.  It has never been frosted.

The tree has been potted for 2 ½ years.  I have not re-potted it.  It is about 14” tall.  It was originally potted in soil that was 50% commercially prepared potting soil and 50% composted leaves.

Our water is very alkaline, so during the winter I water with black tea, made with distilled water and fertilize at about half strength with Miracle Grow.  During the summer I water with rainwater and fertilize with the rest of my plants, again using Miracle Grow, this time at recommended strength.

Have you any suggestions for me?  Any advice would be appreciated.

A. It will be fun for you to grow a citrus in Michigan. I am originally from Wisconsin so I can understand your interest in having a citrus growing in Michigan. First of all make sure the container is large enough for your tree. It will need to be fairly large.

Secondly the tree should be removed from the container every 2 to 3 years and wash some of the soil away from the roots. Cut off some of the roots near the outer edges and repot the citrus in the container using new potting soil. In two or three years the organic matter content of the soil in a container will be gone. The soil would become more compact and the roots of the tree will begin to suffocate. Water will not flow through the container as easily as before. The air spaces around the roots collapse. Root rot begins to set in and this usually causes leaves to start scorching on the edges, yellowing and falling from the tree. Repotting the tree every 2 to 3 years and trimming off some of the excess roots helps to keep the tree young and vigorous. Using new soil increases the air spaces around the roots and helps keep them healthy. When you take the tree out of the container, look at the roots. Healthy roots are creamy white. Roots that are beginning to die turn brown.

When you repot the citrus also reduce the size of the canopy or top of the tree. Look at stems that are too close together or on top of each other and remove them totally. Avoid giving the tree a "Butch haircut". You will generally thin out the branches and open the canopy. If some of the limbs are too long, cut them back so they are shorter and reshape the tree.

Leave the citrus out in the container outside as many months as you possibly can during the spring, summer and fall. They can take reduced sunlight for maybe two or three months but no longer than this. It sounds like to me you are keeping them inside too long. If you have a warm spell during the winter when it's not freezing, put it outside and let it get lots of sunlight. The tree will store this energy inside of its trunk and limbs and live off of it for a time when light level is low and inside the home. If you can put a florescent light close to it, a few inches away, leave it on for 12 to 14 hours or longer each day when it's inside. This will help a lot.

A common problem on citrus are scale insects, usually brown scale. Look for these brown bumps on leaves and stems. If you find them, use a horticultural oil and spray the leaves and stems with it about once a month and you will start to see the populations of this insect decrease. Brown scale and root rot because of watering too often or poor drainage and a lack of sunlight are the worst problems.

Insects on Fruit Easy to Control Without Pesticides. Just Clean Up!

Q. Could you tell me what these little buggars are and how to eliminate them?

A.  This is not a common pest of fruit. It is an insect that just happened to be in the area and found something it could eat, had more of its own and decided you had a place it could set up residence. 

I am not an entomologist but know enough that I could identify it if it was a common pest. It is not. At first I thought it was a sap beetle but it is not. 

Regardless, the control is the same. Pick up and dispose of all damaged fruit on fruit trees and the ground. Compost them or get rid of them. Once you get rid of their food supply (damaged fruit) they will begin to disappear. 

From the look of them they do not have the ability to damage fruit themselves (their mouths cannot chew things) they look for already damaged fruit so they can feed and multiply.

Some Bees are Stingless to Humans

Q. I noticed numerous several small bees swarming around one of my brick planters.  The bees were not aggressive and small … about ½ to ¾ inches long.  There wasn’t a hive of any type, but I did notice a small hole (about ¼ in diameter) in the dirt where the bees would enter and exit.   I did some quick internet research and these appear to be type of Solitary Bee.  Attached are two pics of one that I caught with my pool net…sorry the pictures aren’t very good, but I was hoping that you could confirm that these are Solitary Bees.  They have a black/gray body and the underside is yellow.
If they are Solitary Bees, the research I did indicates that they aren’t aggressive, rarely sting, and are great pollinators.  However, they are a nuisance where they are located.  Do you have any suggestions on how I can get them to move ground nest to another location without killing them?
One of the solitary bees we frequently see signs of in the garden include the leaf cutter bee.
You can build bee boxes or homes for these bees to use for egg laying by drilling one 2:45 eighths inch holes deeply in large blocks of wood.
A. Joe yes these are solitary bees. I am no be expert but my understanding is that solitary bees do
not make be colonies, they do not make sizable amounts of honey, they are not aggressive and they cannot sting. However, I think they get a late start in the season and so early crops such as tree fruits may not be the best for them to pollinate. They are better for pollinating plants that bloom later in the season like summer vegetables and flowers. 

An example of a solitary bee are the leaf cutter bees. You can attract more bees by putting out clean water. They need water to keep cool, honeybees in particular to cool their hives. Honeybees are constantly carrying water back to the hive during hot weather. But the water has to be changed regularly. 

As far as moving them, I don't know any way to move them. I think many of them lay their eggs in these holes and the young bees emerge from them later. That is the way with leaf cutter bees so I'm guessing these guys are similar.

White Flufffy Insects Common Problem on Many Cacti

Q. I appear to have a massive infestation of Cottony Cochineal Scale on my prickly pear cactus. I can usually get most of it off by hosing, but much is hard to reach. Beyond hosing, what insecticide or other kind of solutions do you recommend? Permanent, if possible!

A. Yes, scale is quite common on cacti in general and prickly pear in particular. This one in particular is most likely cochineal scale rather than cottony cushion scale. This cochineal scale is a close relative of the cochineal scale that was used by the Spaniards in Mexico centuries ago and die making. This scale leaves a purple color on your finger when you rub it.They can be hosed off the pads with a strong stream of water as you are doing but they reinfest the pads very quickly and in full force again in a week or two.
            When I am growing prickly pear as a food I am more concerned with insecticides and getting them into the food we eat but if they are grown just as an ornamental plant and not used for food then I feel better about using something stronger than water, soap and water sprays.
            The problem with a strong stream of water is that the force from this water is not enough to knock the insect off of the pad, only the white, fluffy coating surrounding the insect. So it is a short time before it regrows this protective cover and the unsightly mass of cotton is back again.
            Knocking the fluffy covering off first with a strong stream of water will make these insects more susceptible to an insecticide spray. Most of the common insecticides will work after that; malathion, pyrethrins, Sevin, just about any common insecticide will work after the fluffy covering has been removed. This does not mean they won’t be back. They will. But it will take longer for them to get established on the plant again.