Clover-Looking Weed with Yellow Flowers is Very Difficult to Control

Q. I have oxalis clover look-alike as a weed. How can I control it? I am ready to use chemicals at this point having tried to rid it by digging and pulling with no success. Having it in my grass is bad enough but now that it is in my iris beds I want to kill the dang stuff!

Thanks to Hunter for Advanced Irrigation Control at the Orchard

A really big thanks goes out to Hunter Industry and in particular Nate Gould out of Phoenix, Arizona. Nate offered to provide the UNCE orchard in North Las Vegas with a state-of-the-art Hunter ACC Irrigation Clock. This definitely brings the UNCE Orchard into the 21st Century!

Italian Cypress Will Work as a Windbreak on 1 Acre But....

Q. I have used Italian cypress in moderate climates with very good success but now I will be moving to the desert in Pahrump on one acre and want to put in about 30-50 of these for windbreak. Is there anything special I need to consider planting these in a desert climate?

Should a License Be Required to Carry a Hedge Shears?

What was not forseen in the advent of desert landscaping was the dramatic change in pruning techniques brought in by the landscape industry. Hand pruners and loppers were gone. Hedge shears were in.

Still Afraid to Prune Your Lantana?

You may have either the purple lantana or the multi-colored lantana. Most of it died back during the winter. But where to cut? What if I cut it back too far. Will I kill it? Even in February you still have time.

Nevada's First Bottle of Olive Oil All Produced in Nevada

Last year produced the first bottle of Nevada olive oil.

Star Jasmine Problems Mostly Soil, Mulch and Cold Related

Q. What can I do to correct all the issues afflicting the star jasmine this winter?

Things To Do With Fruit Trees Now

While pruning the last couple of days I saw some things  to do that I wanted to bring to your attention.

Not Too Late to Trim and Fertilize Lantana

We generally grow two types of lantana in the landscapes in southern Nevada; the purple one and the one that is multi-colored, usually with some yellow and rose or pink flowers. Both are handled about the same way in watering, pruning and fertilizing.

Please Dont Prune Your Palo Verde LIke This

I was dumbfounded. I saw it from the bus.

Pick Fruit and Check for Circling Roots When Repotting Lemon

Q. I purchased a lovely Meyer Lemon tree in a one gallon pot in middle of the spring. It already had 6 lemons on it. I have the original fruit, have new fruit growing, and still am getting blossoms. Should I transplant it now into a larger pot or wait until after the fruit ripens and is used?

Do Liners at the Bottom of Raised Beds Help or Hinder?

Q. I'm setting up some raised beds for planting this spring and wondered about water evaporation from the soil. Since water retention in the soils here in Vegas is an issue due to the heat would it make sense to put a liner in the beds to help keep the moisture from draining out so quickly?

Remove Suckers Coming From Rootstock on Loquat

Not sure if I should remove growth below the graft from a Loquat tree.

Repairing Lemon Trees From Winter Cold Damage

Q. Our lemon tree shows damage after our recent very cold spell.  Some of the leaves are dry and dropping.  Is there anything we can do to assist the tree?

Ornamental Pear in Bloom Now... A Nice Tree Where it Has Room to Grow

The good and bad about ornamental pear in the desert.

Joshua Pups Can Be Transplanted

Q. I have a Joshua tree that is sending out what I've been told are "pups".  In other words, more trees are coming up around the main tree.  Can I transplant the pups to a new area and how do I do that.  Thanks for your help.

What Makes a Good Compost?

Compost quality can be hard to judge. Part of the quality is what you see and what you feel and smell.

It should smell good. A good quality compost should smell good. It should not have any off odors. No smell of rotten eggs, no smell of ammonia.

Compost should look and smell good.

It should look good. It should be dark brown when moist. It should be ALL brown and not some of it brown and some of it not. It should be consistently brown throughout. You should not be able to discern or see any of the products used to make the compost. Leaves and stems should not be discernable. It should be screened so that larger materials have been filtered out. Some composts are screened with multiple screens to include 1/2 inch and smaller particles (1/2 inch minus). Some are screened even smaller than that... 3/8 inch minus or even 1/4 inch. Screening depends on its use. If it is used on let's say a golf course on greens then large paricles of compost will interfere with the roll of a golf ball when grass is cut at 3/8 or 1/4 inch.

It should be cool. Good quality compost has matured to the point where it no longer produces alot of heat. Compost that is still hot has not finished composting and is immature. Part of the compost process is setting it aside to "cure" after the composting process has completed.

Compost also has qualities that you cannot see.
Pathogens. Generally speaking, commercial composts usually have fewer pathogens that can affect human health than homemade composts. Commercial operations can spend time monitoring and managing a compost pile more effectively than a gardener. Good commercial operations monitor the temperature and moisture contents (and even the oxygen and carbon dioxide levels) so they know when to turn the pile for better aeration, better temperature control and more even processing of the compost. Techniques like in-vessel composting and windrows can generally make a product that has fewer human pathogens in it than static piles that are not monitored carefully.

Chemistry. Even though not considered a fertilizer by law, composts contain plant nutrients. They will add "fertilizer" to a garden. They add lots of other things as well. Trace minerals are present along with organic acids that improve soil chemistry. It is always a good idea to ask for compost test results. All commercial compost operations have them. They should provide a copy if you ask them about it.

There are potentially some things in compost that we need to take a close look at. Salts. All composts will have salt in them. Fertilizers are salts. Some salts are good and some are not as good. Major salts that can be problems for us in our soils are salts of sodium, chloride, sulfates and boron. Salt levels should not be excessive and the salts that concern us should be minimized. I will give more information on these in future postings. Composts that come from large urban centers can contain heavy metals. In commercial composts the level of heavy metals allowed in commercial composts is highly regulated and monitored. They are not in non commercial composts.

Biosolids. Some composts contain biosolids. Biosolids is the preferred name to sludge. This is becoming more and more common as our federal and municipal governments are trying to find an alternative to placing them in landfills. This will become even more common in the future. The use of biosolids is highly regulated in the commercial compost industry with federal limits established by the federal government. I will be discussing this important issue in future postings.

In short, you should and must know what is in your compost before applying it to your gardens. Ask for reports on what is in the compost you are purchasing. Make sure that the facility is submitting samples regularly to compost testing facilities.

Figs Dropping From Tree

Q. We planted a fig tree a couple of years ago. Year before last it produced a couple of figs. Last year there were perhaps a dozen figs which never got larger than a small grape. These did not emerge until November and never grew to full size. The tree was fertilized with 16-16-16 commercial fertilizer, and had plenty of water. Can you tell us why the fruit did not mature and what we might do to have a better result this next season?

A. The usual problem is not watering at the right time and keeping the soil moist during production of fruit. We can get two good crops of figs here. The first one is called the Briba crop and is borne on last year’s wood (2013 growth).

This is the Briba crop. Notice how the figs are developing on older, brown wood from last year. You can see the new growth pushing from the terminal bud, is green and about two inches long.

            The second crop is the Main crop and grows on the current season wood (2014 growth). If the tree is pruned or last years wood is killed by freezing weather, you will only get a main crop.

This picture shows you the larger Briba crop still developing at the bottom on older wood. Above these fruit are smaller fruit still developing on this years growth, the main crop. The Briba crop will be harvested while the main crop is still developing.

            The main crop occurs when it gets hot and if the tree is not getting enough water the figs will get button sized, get hard and drop off. There is a potential third crop in about September and October but the weather does not stay warm enough in the fall for it to mature.

            This third crop will get button sized and will fail to develop due to winter weather coming in. That third crop may form without the summer crop if the tree is not getting enough water. Then in the fall it is getting enough and tries to set fruit but it is too late and fails.

Although this is another readers picture, this is what this reader is probably talking about. Late season figs never get to ripen. However, if you keep the soil moist during the summer months, the first two crops will ripen.

            I would mulch around the tree with about four inches of wood mulch and cover the soil to a distance of about six feet from the trunk. Water in a basin around the trunk about six feet in diameter.

            The basin should be able to hold at least two inches of water but four would be better. Fill the basin with water each time you irrigate. Water once a week now, twice a week in May, three times a week in June, drop it to twice a week in September and once a week mid October.

            Once the leaves fall off in winter you can water about every 10 to 14 days. Fertilize once in February with a fruit tree fertilizer or four fertilizer stakes per tree, one in each quadrant of the irrigation basin.

What To Do to Fruit Trees Now

Q. What should we be doing to our fruit trees right now?

A. You should be finishing your winter pruning now. Bloom on some fruit trees started early this year and if you haven’t finished it you can still go ahead while it is in bloom. Be careful of the bees.

            Hold off on pruning grapes until later in February when the chance of freezing temperatures has passed.

            Fertilize your fruit trees now if you haven’t. Use a balanced fruit tree fertilizer high in phosphorus. If you miss this application you can use three or four liquid applications to the leaves (spray) a week apart in the coming weeks.

            If you suspect you will have yellowing due to an iron deficiency, apply the iron chelate EDDHA to the base of the tree with your irrigation water. Trees susceptible to iron problems include peach, nectarine, plums, apricots, almonds, apples and pears.

            Before or immediately after bloom, but not during bloom, apply dormant oil to limbs and trunk making sure you spray the undersides of the leaves, not just the tops.

            Irrigations should be once a week as soon as you see new growth. Newly planted trees can receive 5 to 10 gallons. Trees that are up to ten years old should receive 20 to 30 gallons each time you irrigate. Irrigations should be applied to at least half of the area under the canopy.

            Prepare for thinning fruit trees of excess fruit in about a month. Summer pruning will occur in about April. Watch for my postings on future activities and when to do them.

Potted Meyer Lemon Flower Drop

Q. You helped me before with my Meyer Lemon, so I hope you have an answer for this one.

My tree is in a huge pot. It is about 4 years old.

            Last Spring, it had massive flowers (yum) and a lot of little green buds followed. Then every single one of those buds turned black and dropped off.  Not one remained.

I want to figure out why and change what I am doing so this never happens again.

            The plant is fertilized with granular fertilizer 2x a year -- early spring and late summer. It gets moisture and hasn't dried out.  However the leaves could look more beautifully green.

Sometimes, some of them curl and are not quite bright green.

            I do not know if the two issues are related, but I sure hope you have a suggestion.

A. Sounds like you had post bloom fruit drop. Fruit drop can also occur during summer months and just before harvest. The usual reasons for post bloom fruit drop is usually some sort of stress.

            Four years is getting up there for being in the same pot without repotting. You might consider repotting and adding some new soil to the mix.

Meyer lemon flowers

            I know you said it had adequate water but if it went through just a few hours of drought during or just after pollination, fruit drop may occur. If we have some freezing weather during or just after flowering, that can cause the fruit to abort too.We had some on January 6 and 8 in parts of the valley.

            When watering, make sure about 20% of the water that you apply runs out the bottom of the container each time you water. This is important for flushing salts from the soil.

            Another possibility in containers is overheating them. If in direct sunlight and the outside of the container gets too hot and transmits this heat to the soil, this can cause stress and cause fruit drop.

            Proper fertilization is important. Over fertilizing fruit trees, excess nitrogen, can cause fruit drop. And finally less commonly some insects such as scale or mealybug infestations can cause fruit drop as well.

            What to do? Make sure your container, the soil volume, is big enough to handle wide swings in temperature and water. Monitor both closely. You might find a houseplant moisture meter to be helpful.

             Keep the outside of a plant container out of the hot sun. Double potting a container is  helpful to keep the soil temperature down. Watch for freezing temperatures at bloom time and cover the plant.

            Water the soil just before the heat of the day. Wet soil heats up more slowly than dry soil. If we have any frost during bloom it will affect fruit production.