Type your question here!

Friday, July 8, 2011

Privet Not Doing Well

Q. I have four bushes like the one shown. They were planted about six years ago and have never done very well. Each year around this time they look as shown. Can you advise suggest anything?
Reader's suspected Japanese privet

A. From the looks it appears to be Japanese privet which must have soil around its roots that does not go dry. It will not do well in rock landscapes. They do well in a turfgrass landscape. This might be a case of the wrong plant in that location. You would have to increase the frequency of the watering and improve the soil in that location.
Leaf tip burn on readers privet
The amount might also have to be increased but since I dont know the amount I would suggest increasing the frequency to about three times a week. The amount depends on the size of the plant but a three foot tall plant might require five gallons or so each watering. A ten foot plant might require perhaps 20-30 gallons at each watering.

African Sumac And Leaf Drop

 Q. I have an African sumac in my backyard that has leaves which turn brown and fall off.  I have one in my front yard that does not do that.  The one in the back is close to grass which gets 5 minutes of water three times a day.  The one in the front is in a rock landscape and gets a lot less water.  Is this a natural for them or is it getting too much water or not enough fertilizer?  The backyard one is on the east side and the one in the front faces west which is very hot.  The one in the back is about 15 years old and about 35 feet tall and wide.  Any help would be great.

A. Sometimes they can get so dense that internal shading of the canopy will cause leaves to die and drop. These are fairly messy trees due to leaf drop and dropping of their berries. If the tree in the drier landscape is more open and the tree in the back is more dense then this can be the reason.

Other reasons might include pest problems such as aphids which can cause the leaves to be sticky or shiny and leaf drop if there are in large numbers.  If the leaves are sticky, try spraying with repeat applications of soap and water or insecticidal soaps.  Aphids should disappear during hot weather but reappear again during cool weather.  You may also see a lot of ant activity that are working off of the aphids sugary honeydew droppings.

You can try to open up the canopy with some branch removal (thinning of the canopy by selective limb removal) and admit more light inside the canopy. This however will probably cause some suckering on the limbs if too many limbs are removed.

Another possibility could be overwatering. If the tree is watered too often it is possible to develop root rots and lead drop will occur and usually branch dieback. 

My Lawn Needs Help Doggone It!

Dog urine damage. You can tell because it is darker
green around the dead spot due to the extra nitrogen
in the urine.
Q. I have some grass in my backyard.  I installed sod when I first moved to this house and 7 years of having two dogs and three kids have done its damage. I have large patches of dead spots and the live spots are not looking so good either. Haha. The problem with reseeding or sodding is that one of my dogs is still 7 months old and would tear it up as it happens. I was thinking of getting some Zoysia grass or something like that.  What brands do you think do well here?   My other option is artificial grass and that is a bit pricey right now.

A. If dogs or a dog is tough on your lawn then there isnt much you can do about keeping a lawn looking good. Even zoysia grass, as tough as it is, will have problems with dogs and kids who play outside alot and roughhouse.
El Toro zoysiagrass
Artificial grass has its drawbacks. Number one are the temperatures it can generate even on a moderately warm 95F day. Surface temperatures of artificial grass can climb to well over 150F on a modestly warm day, midday in full sun. Artificial grasses need to be kept clean since small surface debris does not decompose as it does in a lawn.

If you do elect to use artificial grass make sure it is in the shade. If you elect to use a natural grass you might want to consider Kentucky 31 tall fescue. I normally do not recommend this grass for most lawns because of its coarse texture. It is not a pretty grass to look at but it is tougher than just about any other cool season grass. It can be reseeded easily in spring and fall months. But it is a water hog.

Try rotating your pet into different parts of the lawn at different times so that grass which has been beat up pretty bad has a few weeks to recuperate before fido is let on that patch again. When fido has been rotated off of a patch then fertilize it, aerate it and push some new growth to get it to recover as fast as it can.

Baked Apples on the Tree in July

Apple baked on the readers tree and now rotting
Q. Aloha, Bob. I have this problem. Our Apple and tomato crop has been developing brown areas usually on their bottoms. I am attaching three photos so that you see what I am writing about. Our apples seem okay except for the brown spots but, our tomatoes also develop cracks at times, usually about half way to maturity. Can you help? If it's any help to you, we live in the northwest part of the valley two blocks from the Santa Fe Station Casino.

Apples on the readers tree
A. The apples on the tree looked like Anna.  Is that correct?  This is high temperature damage to the fruit.  They basically cooked on the tree.  I have had this same problem with Anna apples at the Orchard. Cut the apples open and look inside the core to make sure that there were seeds developing and check to see what stage of development they were.  When an apple fruit is mature the seeds will be dark brown with maybe the pointed tip still white.  I just want to make sure that the fruit was mature and that you had pollination for fruit development.  If there are seeds present, then it makes it more conclusive that it is due mostly to high temperatures.

Anna apple with high temperature damage
at the UNCE Orchard
I want to add that you did a great job thinning your apples at the right time to get that size.

Apple fruit at beginning stages
of sunburn
Apple at advanced stages
of sunburn
If this is Anna apple they are pretty good at handling high temp stress.  They mature early and you can often times get them off the tree before the hot weather can do substantial damage.  I typically do not like apple trees which have fruit that matures at the peak of our summer temps.  I usually prefer apple trees that produce fruit late, such as mid September through November. 

I also like apple trees that produce enough leaf cover or canopy to shade the fruit and not have it exposed directly to sunlight.  Exposed fruit can be damaged by sunscald, a different problem but related to high light intensity that produces a lot of surface heat on the fruit and causes the fruit to discolor on the side exposed to the sun. 

I think producing its fruit in November is one reason Pink Lady apple does so well in our climate besides just having a wonderful balance of sugars and acidity and a great flavor profile of sweetness and acidity.

I am thinking, again if this is an Anna, that it might be due to a long cool spring and summer we had followed by the onslaught a very high temps, very quickly when the fruit was maturing.  Again, if this is an Anna, I don’t think you’ll see this again in future years unless we have a repeat of these weather conditions.

Wednesday, July 6, 2011

Mason Bees Probably Not the Best Choice for Desert Pollination

Bee boxes made for leafcutter bees at The Orchard
Q. Do we have mason bees in las vegas? My yard is 50ft x 25ft. do you think it’s a good or bad idea having a mason bee house?

Circular holes cut on the leaf magin of a bottle tree leaf.
Leaf cutter bee house and bee entering hole
A. We don’t really have Mason bees or Orchard bees that I know of. We rely mostly on leafcutter bees as a wild source of bees for pollination. I have sat in the orchard for about one hour a few years ago during full bloom and counted bees visiting flowers on a peach trees. The leafcutters are smaller in size so they are easier to distinguish from Italian honey bees. We have ten hives of Italian honey bees in the orchard. My best estimate was that about 25% of our pollination on that tree was due to leafcutter bees.

I think you would waste your money in bringing some in. I think they might die in this climate. You can make your own leafcutter bee house by drilling holes in a 4x4 or 6x6 (better) or a tree stump with a 3/8 inch bit to a depth as deep as you can. Five inches is best but at least 3 inches. The female bees will lay their eggs in these long tunnels created with your drill bit. The State Entomologist in Nevada claims that the longer tunnels will favor the creation of more female bees since the eggs of males are laid the first three inches or so of the tunnel. The deeper the hole, the more eggs that turn into females will be laid. Shallow holes will still provide for the production of bees but male bees will be favored. As we all know, male bees are not as productive workers as females.

Basil damaged by leafcutter bee
You might keep in mind that leafcutter bees will make some damage to some leaves around your yard or garden but that's okay. They will grow back. Leafcutter bees favor leaves that are smooth and fairly delicate such as bougainvillea, roses, grapes, basil and the like. They take these leaves and use them to stuff the tunnels where they pack their eggs. The leaf stuffings provide protection for the eggs and food for them to eat as they emerge in a month or so.

Monday, July 4, 2011

Twisted and Distorted Tomato Roots May Be Nematodes

Nematode damage to roots
Q. I recently pulled up the remains of my tomato plants and found the roots disfigured but I could not see any of these worms on the roots.  I planted tomatoes that had a VFN designation on the label and thought they were resistant to nematodes.  Are these the remains of nematodes? 

A. Nematodes are microscopic worms so you would not be able to see them with your naked eye. Just because they have the label nematode resistant (N of VFN) doesn’t mean you can’t get them. It just means that the plants can resist infestations but are not immune to them.
            From your picture it does look like a nematode attack. You should remember that it is extremely important that you not grow the vegetables of the same family in the same spot year after year. You rotate the locations of where you plant vegetables each year. This will help in keeping diseases and nematode populations from building in certain locations. However, nematodes are a different problem. Some guidelines for control are available in this publication from Clemson University.
             Regarding reducing nematode problems there are a few things you can do and one is solarizing your soil. I have sent to you a document on soil solarization which can be seen on my blog. This technique will help reduce the population of nematodes but not eliminate them. Continue to use vegetables with an N designation on their label or seed packet.
            You can plant cover crops such as cover crops that have been shown to suppress nematodes include annual ryegrass, wheat, barley, oats, sorghum and sudangrass.
            Another technique is to keep your crops outgrowing the nematode attack by keeping them well fertilized and healthy. So far there is not much else you can do to eliminate them once the soil is infested except fumigating the soil, another topic.

Transplanting Joshua Tree Success - Now Will It Live?

Joshua's old home on Eastern Avenue.
Water was cut off five years prior.
Q. I am sending some pictures of a Joshua tree that I transplanted. It survived in its old location off of Eastern Avenue for five years after the water was shut off. It also survived with its trunk buried with about a foot of soil. I am adding it to my drip system but I need to optimize my watering so the tree has its best chance at survival. I amended the planting hole with sulfur and bone meal. I watered it deeply every three to four weeks by hand. Now I have drippers that are watering for one hour every four days.  In addition I frequently wet the top portion of the plant up to 5 times a week in hot weather to keep it from drying out.

A. These are tough to transplant and this tree was abused and still survived. It shows you how well adapted these plants are to our desert environment if they are not watered too often and carefully relocated.
Joshua lifted with engine hoist
and seatbelts by reader

            The key will be watering with lots of water but not very often or you may rot the trunk and any roots that might grow. I would suggest watering about every two weeks with about ten to twenty gallons in a depression around the trunk.

            After the plant shows signs of new growth then the frequency of your watering will dictate how it looks and grows. If you want a Joshua tree with limbs that are long, kind of spindly and solid green then continue watering every two weeks during the summer. I have a hard time aesthetically liking this in appearance I guess because they do not look this way in nature.

Old soil level just below orange belt.
Roots covered with burlap.
            If you want a Joshua tree with a tuft of green growth at the ends of the branches and the rest of the limb brown (more like you see in nature) then don’t put it on drip irrigation. After signs of new growth, begin watering seasonally by hand with a large volume of water around its base. What I mean by seasonally is water deeply perhaps once or twice in the spring, once during the summer and once during the winter. At some future date you may elect to eliminate the summer watering if you want more brown on the limbs.

Joshua in its new desert landscape.
            Make sure it is staked securely in the soil so the trunk at soil level does not move for one growing season. This plant will respond to a new location if you use soil that has been amended with compost or other soil improvements.

            Wetting any part of the aboveground tree with water like spraying it with a hose or mister is a waste of time, not needed and may prove to be detrimental to the plant.

Maybe Green Manure Crops Might NOT Be the Best Idea in the Desert

Q. I have a 1/2 acre on the east side of the valley ( Las Vegas), the lot is divided in quadrants with the house in one, a barn in another, yard/parking in the third, and the fourth is my chicken run. I was researching the idea of putting an orchard in that area and your work in NLV keeps popping up, but I can't find your list of trees or an article on your high density planting techniques. I know the soil needs improving so I am currently trying green manuring with buckwheat and soybeans. I figure that one way or the other my chickens will like it. Any help you can point me towards I would appreciate.

A. If you will go to my blog Xtremehorticulture of the Desert and in the search engine type "recommended fruit trees" you will see my recommended fruit tree list posted twice; once as a downloadable pdf document and the other posted in its entirety.

This past year the only nursery to carry my recommended fruit trees was Plant World Nursery on Charleston Blvd. Any of their fruit trees with a hanger or tag from Dave Wilson Nursery, a large commercial grower of fruit trees, is from my list. A local producer sold my recommended fruit trees to the public as bareroot trees but will not be doing that this fall. Anyone want to take it on? Contact me.

The idea of high density planting is not mine but adapted from Dave Wilson Nursery out of the Modesto, California area.You can find more information on concept of multiple trees planted in a single hole at davewilsonnursery.com, along with a lot of great information on growing fruit trees.

I produced some YouTube videos on growing fruit trees which can be found by typing "UNCE orchard" at the YouTube video website, another resource. Here is a sample on controlling the size of fruit trees.

Green manure crops are plants that can be started from seed which will either capture low amounts of nitrogen that exist in the soil or capture nitrogen from the air and return it to the soil. They also decompose and add organic matter.

I have mixed feelings about using green manure crops in the desert. Although they are tremendously beneficial to our soils and highly advantageous in most areas of the country, they may or may not make sense when using them in the desert depending on your situation.

The principle reason is water use. A secondary reason is the time that green manure crops take out of production. And thirdly is their cost. Green manure crops take time for the seed to germinate and the plants to grow to a size where they can be beneficial when turned back into the soil. Normally plants are allowed to get to a juvenile or early mature stage before they are turned back into the soil. This takes time, perhaps 5 to 6 weeks or longer which is time taken away from your production.

If you have plenty of space and the cost of water is not a concern then this makes a lot of sense. But if your space is limited and water is costly then this will probably not make a lot of sense for you. It may make more sense to concentrate your space and water into making compost.

Seed can be very expensive so look for inexpensive seed locally that you can use rather than to have it shipped in from some other location in the country. This also helps to lower your carbon expenditures for your small farm or garden.

A very good green manure crop that is inexpensive is annual rye grass. This is the same inexpensive rye that is used for overseeding Bermudagrass in the fall. Grasses, and in particular annual ryegrass, are fast to germinate when temperatures are at least 60° F. You can even speed up its germination by soaking the seed for 24 hours before planting it. The seed must then be carefully dried so that it is dry to the touch but not overly dried or the seed may be ruined.

Legumes harvest nitrogen from the air primarily and are not that terribly good at taking residual nitrogen from the soil. But they are an excellent choice for poor soils if you can get the seed inexpensively.

Annual grasses are wonderful at finding nitrogen in the soil that vegetable crops miss and they take this nitrogen and bioaccumulate it or, in other words, put it into its own plant tissue. The grass is watered and allowed to get about 6 to 10 inches tall and then turned into the soil just before it produces a seedhead. This nitrogen in the plant tissue is then slowly released as the rye plant decomposes in the soil.

However, using a green manure crop in a mixed planting where you are combining an orchard with chickens or other fowl makes a lot of sense provided these animals do not ruin in your production. I could see how you might be able to have a small orchard and, using the existing water required to irrigate your fruit trees, grow some green manure crops for soil improvement and that would also double as food for your fowl.

Keep your costs low by growing winter and summer green manure crops from seed that are inexpensive and that will do well in our climate. Some manure crops for our area might include annual ryegreass, timothy, wheat, oats, alfalfa, peas and Kentucky 31 tall fescue. But if you use tall fescue be sure to turn it into the soil while it is still young.

Just about any inexpensive seed will work if you know the germination temperature of the seed. Don't use bermudagrass. Recommended green manure crops from other climates may or may not work well here and it may be difficult to find inexpensive seed.