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Tuesday, July 10, 2012

When Are Different Fruits Ready to Harvest in Southern Nevada?

Q. Do you have a rough timeline of peach production for different varieties.  I would like to go out to the orchard to try some of the different types you have out there so I can decide what I want to plant next spring.  Do they keep track of what they pick and have to sell at the stand so I can know?  When are pluots generally ready for harvest?  Is there a source or another newsletter for the orchard of what is producing and ready for purchase?  Also, will you or someone be organizing a bare root order again this fall?
A. There is a great timeline for most fruit tree varieties which can be found on Dave Wilson Nursery website at http://www.davewilson.com/homegrown/promotion/chart.html
Dave Wilson bare root fruit trees arriving
at the Orchard in North Las Vegas
            We have matched our production dates at the Orchard in North Las Vegas with those on this chart and they are usually within two to three weeks of these production dates. You will find on this chart many varieties of peaches, apricots, plums and many other fruit tree varieties and when they produce their fruit. Download it, it is a pdf file and you can enlarge it to see it better.
There is no flier or newsletter notifying you when fruit is ready at the orchard.

            As far as whether the orchard will be carrying bare root fruit trees it is best to contact the Master Gardener helpline, 702-257-5555, and find out. If they are putting in an order for fruit trees it will be in September so don’t wait until December to order. It will be too late.

The Proper Way to Prune and Hedge Oleanders

Formal oleander hedge, no flowers
Q. Would you please comment on the proper method and timing to prune and hedge oleanders.  This is two questions.

A. There are two types of hedges; formal and informal. You have to make up your mind which kind you want. Formal hedges are pruned with a hedge shears while informal hedges are pruned with a loppers or even a pruning saw.

Formal hedges are supposed to be pruned so that the bottom is wider than the top but they are maintained in a tight boxy shape. To maintain them properly, formal hedges need to be pruned two to three times during the growing season to keep the new growth restrained and maintain that boxy shape.
Oleanders flower on current season or summer wood
            Informal hedges can be pruned every two to three years, most of the pruning is done at or near the soil level and is done during the winter months. Formal hedges are best done on nonflowering plants that have small leaves. Informal hedges are best served by other types of plants, particularly those that flower during the summer.

You can prune any plant used for hedging in any manner you want but there are some big advantages in picking the right type of hedge for the right plant.

            Oleanders flower on new wood. In other woods after the winter rest its new growth supports the flower throughout the summer. Formal hedges, since they are pruned to maintain that boxy look, are pruned during the time of year when it is growing. If it wasn’t pruned then, in a few short months it would no longer be in that boxy shape. The problem you can see right away is that in picking a formal hedge for oleander you will prune off most of the wood that supports flowering so it will be pretty much a green hedge.
Shubs in this streetscape are "hedged" for no apparent
reason other than creating more income
            If you want to enjoy the flowers then convert it to an informal hedge. The problem is that 95% of the maintenance companies DON’T KNOW HOW TO PRUNE FOR AN INFORMAL HEDGE.  And it is very simple, there is far less mess, the cleanup time is very short but you ONLY HAVE TO DO THIS EVERY TWO TO THREE YEARS.  Now if I were a maintenance company, which type of hedging would I like to charge for. Hmmmm…. Once every two to three years or two or three times a year….

            Now if I really want to do a lot of work then why not make ALL the plants in a landscape boxes! That way I would have to prune them several times a year rather than once every two to three years! If I can’t make money mowing a lawn any more then lets charge for making all the plants in a yard into boxes… or gumdrops.

            Pruning for an informal hedge is quite simple. During the winter, once every two to three years, remove one third of the plant at or near the soil level. Pick 1/3 or ¼ of the largest stems and cut them off. This will only work on shrubs that have lots of stems coming from the ground. On plants which have a single stem or only two or three coming from the ground then you have to move this technique higher in the plant and inside the canopy.

Loquat Turning Brown in Rock Mulch

Andy's loquat

Q. I planted a five gallon loquat in my front yard three months ago in April .  It seemed to be taking just fine at first.   A few weeks ago I noticed that the older leaves were beginning to turn brown and  the newer leaves seem to be shriveling up.  When I purchased it I was told it was OK to plant in full sun.    
During this heat I drip water it every two days.  I estimate it receives about six gallons per watering.   I check the soil regularly to make sure the soil is not drying out.  Any thoughts.

Attached are some photographs. 

Closeup of Andy's loquat

A. Andy,
As you found out Loquat will not like it in rock mulch in full sun. It will do all right in full sun in a mixed planting with lots of other greenery around but it will actually do better in a more protected location.
If you can put it in an area with protection from late afternoon sun and surround by other plants it will perform better. Loquat does tend to get borers easily if heat stressed.

Some Cacti Can Be Grown for Fruit

Nopal fruit or tunas
Q. I would love to put op-a-la-ah (not sure of spelling) cactus. the kind that looks like mickey mouse ears and grow red cactus pears aka prickly pears. several of my neighbors have them. the problem is the tiny stickers on the fruit. I have heard that there is a variety that does not have stickers. please advise me what they are called and where to get them.

A. I am sorry but I could not figure out what cactus you mean. However, I have grown cactus for their fruit. The fruits that we see commercially typically come from Opuntia cactus. These fruits, called tunas in Mexico, are harvested ripe from the pads. Typically we can see both red and yellow or green fruits. If you have the right type of cactus or selection they can get pretty high sugar content.

Dragonfruit orchard in Vietnam
            I don’t know of any totally spineless ones that have good fruit but there are some which are nearly spineless but you still have to prepare them with caution. Wear gloves or use newspaper to protect your hands and use a sharp knife. If you look at the harvested fruit it resembles a barrel in shape.
            The ends of the barrel are cut off and the sharp knife then cuts down the fruit lengthways (barrel end to barrel end) just below the skin of the fruit. The skin is then peeled back exposing the inner pulp. The pulp is full of hard seeds but the pulp is sweet.
            Other cacti can be grown for their fruit as well such as the vine cacti like the pitayas and dragonfruit, some columnar cacti like the cereus.

Using Herbicides Can Reduce Landlord's Weed Problems

Q. Please tell me if this is not the correct way to send you a question, your blog is great.  We are still trying to move out from New York, the house we own out there has a good size back yard, and with tenants in the house until we can move, the weeds are not usually pulled, so although I hate to use pesticides I think we need to.
            When should we use pre-emergent and post emergent pesticides for the greatest effect?  We want to keep the weeds down, but don't want to poison the trees or shrubs (or the ground) any more than absolutely necessary.  thanks very much.

A. Yes, you can reach me at Extremehort@aol.com or through my blog or newsletter.
Herbicide damage to a lawn. Herbicides were applied to the
shrub area and water moved the weed killer into the grass
where it was not supposed to go.
Pre emergent herbicides are applied to the surface of the soil and watered in lightly. They kill germinating weed seeds by putting down a barrier poisonous to many different weeds that germinate from seeds.
            The timing of this is usually in the spring, with applications scheduled about the first of February for many weeds. The barrier must be in place and active when the seeds germinate. The soil is cleaned up of any existing weeds and the pre emergent weed killer is applied. Once the barrier is put down the soil should not be disturbed or you will disturb this barrier.
            There are several weed killers to pick from in the nursery or garden store. Read the label to find out how to use it best and any potential dangers.
Wood mulch applied to fruit trees to reduce the weed problem
            Post emergent herbicides are applied to weeds when they are present. These are chemicals like Roundup that are nonselective and so will kill many different types of weeds but not all weeds. Round up will kill or damage anything that is green and sprayed. Direct it on to the weeds, not plants you value.
            Timing is critical and these weed killers work best when weeds are actively growing and not during times of stress like from heat or drought.

            One very effective method of weed control are mulches. This is a thick layer of wood mulch or rock mulch that covers the soil surface and helps prevent weed seeds from germinating. Post emergent weed killers are then used to kill weeds that emerge from the mulches.

Shoestring Acacia Losing Lots of Leaves

Freeze damage to shoestring acacia
Q. I had three shoestring acacia trees planted 5 years ago and right now they are losing a tremendous amount of leaves. They are on high flow emitters that are adjustable and putting out a large amount of water. They get watered every other day for 15 minutes. The trees are approximately 20 feet tall.
            Is there any reason why they would lose so many leaves?  My understanding with these trees is they produce very little litter but that is not the case. I would appreciate any help you could give me on this. Also there are 4 emitters for each tree about eight to ten feet from the trunk.

A. Shoestring Acacias (Acacia stenophylla) has a long record of success in desert regions of the west.  This good history of success is often the result its adaptability and letting the soil dry between waterings. 
Flowers of shoestring acacia
            Your comment that the 'leaves' are falling (Oddity fact: The long thin 'leaves' are in fact phyllodes and not true leaves but do the photosynthesis) leads me to think the very frequent watering has set up conditions not conducive for a maturing tree.

            After 5 years in the ground I would think your watering cycle could be as much an issue as anything.  Unless you live on some of the very sandy, stable dune soils of Palm Springs or in southern California/southwestern Arizona (Yuma mesa area) trees in the ground for 5 years would be better watered much less frequently with a larger volume at each watering.  This would also include having the source of the water being moved out away from the trunk targeting the water out closer to the drip line of the tree. 

            Whether there might be a disease involved and complicating the situation is nearly secondary.  The watering regime you described could easily have set up the conditions for the fungus to get started and any treatment would include a change in watering schedule to allow drying between waterings.
            Please feel free to respond if you have any questions or other things that might have 'hit' the tree. Things like: root damage from digging, severe wind that may have damaged the trunk, certain herbicide (weed killer) usage, pool back flushing, inadvertent chemicals spilled in the area, compaction from parking vehicles in the tree's shade, etc. 

            I would be interested if you live in a marginal cold area.  This tree begins to suffer if the temperatures drop to the high 'teens.
Terry Mikel

Leaves of Shrubs Dry, Burnt and Falling Off Could Be Several Reasons

Leaf scorch on Cherry Laurel
Q. I now water once a week but my shrubs are looking like they might in the hottest part of the summer. Leaves look dry, burnt and falling off. My average shrub is about 3'x3' and receives 3-4 gallons per week week based on my emitters and time on. Did I cut back too much ? What should I do to try to revive them ?

A. Your watering sounds very appropriate and probably what I would have scheduled as well. You have to make sure, however, that the water which is scheduled to be delivered to your plants is actually getting there. Make sure you check for plugged emitters when the system is on. You should have a filter on your drip system even if you are on city water.
Leaf scorch on mockorange due to chlorosis and inadequate
plant nutrition
             It could be several possibilities. I have to walk through them with you because I don't know much about their previous history. For me, it looks like possibly watering, possibly collar rot at the base of the trunk where the rock mulch sits against the stem, it could be very low temperature damage as possibilities. If there were some very low temperatures just prior to that than this could be just that. If there were no low temperatures than most likely it is not. Then we have to look at watering issues including the rock against the trunk.

First determine whether the plant is dead or not. Bend some branches and see if they snap. If they are still supple and just have damaged leaves then it is a temporary setback and they will regrow and set new leaves in the spring. If they snap when you bend them, it may be dead. You will have to pull it anyway so start bending the branches and see how much of the plant is dead. If the amount is sizable, remove it. When you remove it look at the trunk where the rock mulch was resting against it.
Planting so shallow that the container mix from the nursery
is exposed to the open air and wicks water from the
Use a knife or your thumbnail and scrape the bark away from the trunk starting about an inch above where the rock mulch sat and down along the stem to the roots. Look to see if there appears to be a dark area or rotten area in the trunk or bark around the rock mulch line. If there is, then it is collar rot. Make sure on any new shrubs that rock mulch does not lay against the trunk or, in some cases, the plant was not planted too deeply. It should have been planted the same depth as it was growing in the nursery container.

Nurseries don't have many plants this time of year because they are trying to reduce their inventories. You can look for a replacement plant but chances are you may not find one that you like until next spring when it gets warm.

I hope this helps.

Flies A Big Problem in Parts of the Las Vegas Valley

Q. My husband and I spend four months away from the Valley during the summer. When we returned in late September we could not believe the number of flies in our yard.....and because we are used to leaving our doors open....in our house. We have always bragged to those less fortunate than we are and live elsewhere in the country, mainly in the East, how we have virtually no flying insects in Las Vegas. I've had to eat my words this fall....along with some flies. I have not been able to even sit outside and read without being bombarded in the face with these nasty insects. We live in Sun City Anthem....the far southern end of the valley. Is there something blooming/growing in my yard that flies really like? Has anyone else noticed this proliferation?

A. Yours is the first report I have seen about an increase in flies this year. I do not know the products that are used for flight control, which is not an area of expertise for me. I would suggest however that somewhere, someone may be using a source of compost or manure products that are attracting flies.
The best advice I can give in the safest is to find out what is attracting them and where and address the problem there. If you do not do it this way and simply spray to control flies or use some sort of sticky trap you will not solve the problem but just work on the symptoms of a problem. I hope this helps.

PS. Since this was printed in the newspaper several people wrote to me and said they had the same problem. I lived in the valley at the time and I didn't really notice it. Anyone else have any suggestions?

White Fluffy Stuff on Cactus Can Be Removed Easily

Cochineal scale on Opuntia or beavertail cactus
Q. My wife and I read your interesting article regarding white spots on cactus. Yes, we have them and didn't know what to do about it. Now we do. I zapped the beavertail with a solid water stream and within seconds the spots were gone and the beavertail looked as good as ever. Many thanks for the simple solution to an otherwise difficult problem.

Using a hose and sweep nozzle to wash off cochineal scale
A.This is cochineal scale. A very similar cousin to this one was used for making a beautiful red dye. Remember that this does not get rid of them permanently.

They will come back relatively soon and you will have to repeat spraying with your hose. If this becomes bothersome then you will have to rely on a pesticide such as Sevin after you hose them off.

Make sure you read the pesticide label before applying it.

Blue Point Juniper Unique to the Las Vegas Area and Probably Has Mites

Q. My 9-foot tall cone-shaped blue point juniper has a huge area that is turning brown. What can I do to restore the burnt-like brown to a normal green? I looked at the brown area closely and found whitish cobwebs with little white dots on the area.  What mites are inhibiting the juniper and what is the best way to get rid of them?

Click here to see a Blue Point Juniper

A. Junipers are notorious for two things and uprights possibly a third; spider mites which are frequently associated with webbing, root rot when they are planted in heavy soil or if they are watered too frequently or both and possibly borer damage. Damage from overwatering usually appears at first as single branch dieback.
            Blue Point Juniper is a small to medium sized upright very small tree or shrub that is cone shaped with a bluish green color. This is a very pretty plant in the right landscape. I have not seen very many of them growing here in our landscapes.
Webbing from spider mites
            Spider mite damage can cause browning but normally the surrounding foliage of the juniper appears to be dusty looking. Most of this dustiness appears, to me, to be dead mites. Spider mites are extremely small, about the size of the period at the end of this sentence.

            The webbing may not mean anything. Just because there is webbing does not mean it has a problem with spider mites. Spider mites can be of a type that creates webbing or it may be of a type which does not. Secondly, there are good mites and bad mites. The good mites help to control the bad mites so spraying a chemical aimed at controlling mites may just backfire.
            The best way to determine if spider mites are an issue is the paper test. Take a white sheet of paper and a branch of the juniper and slap the branch or foliage against the white paper. Hold the white paper still and look at the dust or debris on the paper. If spider mites are present you will see a number of tiny dots the size of a period moving on the paper.

            Usually spider mite problems begin developing during the heat of the summer, not when it is cool. Soap and water sprays once a month during the summer is a common way to try and keep spider mites from becoming a problem. If the problem is severe than that may require a miticide or insecticide for controlling mites.
Scanning electromicrograph of spider mite the size of a
pencil dot.
            Since you have had this juniper for quite a while it is probably not root rot due to overwatering unless you have recently changed the irrigation pattern or if there has been a release of water near the plant in the past few months. This might be from a leaky irrigation valve or broken pipe.

            Borers in major limbs or branches are a problem on some upright junipers such as the Hollywood twisted juniper. It might be on this plant as well. Boring insects that tunnel into these branches cause these limbs to die while the surrounding area stays green. Pull the canopy of this juniper apart and look at the limbs inside of it to see if there is sap coming from a limb or limbs. The damaged limb is pruned out just below the sappy area.

            Once a branch is damaged and it has turned brown it is difficult to get it to come back to green again. If the damage is not severe it might come back over time if the problem that caused the browning is corrected. If the damage is severe it may be permanent like the toothless gap of a smile and never repair itself.

            The nurseries to carry a green paint that can be used to help the plant cosmetically. This is a problem with plants that grow beautiful, perfect cones of canopy.

Thank your very much for your detailed response.  My two blue point junipers are doing quite well now after I sprayed them with insecticide.  I live in Sun City Anthem and you are right--nobody else has these trees.  Mine are now six years old, eight feet tall and trimmed to a conical shape.