Early blooms on pluot trees may not produce fruit

A: Anything in flower is subject to fruit loss in Las Vegas all through January, February and the first two weeks of March. Ninety percent of the time March 15 is officially the “last” freeze day in Las Vegas.

If you have a plant that has open flowers in January or February, then you are gambling it will produce fruit. That is why I am constantly talking about a maximum/minimum thermometer for your backyard. All local backyards vary in their freezing temperatures during the months of January and February.

Honeybees fly anytime the temperatures are above 55 degrees and not too windy. A lot of their presence depends on whether a hive is nearby as well as plants that flower in the winter or not such as rosemary and roses.

Flavor Supreme pluot has irregular production each year. It does not flower in January but later in about mid-February. Nothing flowers in January except the semi-tropical citrus. If there are no pollenizers (honeybees) present, then there is no pollination.

The earliest flowering varieties of temperate fruit trees (peach, plum, apricot, apple, pear) are the earliest peach varieties such as Earlitreat and the University of Florida releases called FlordaPrince and FlordaKing. There are some very early apricots, following the earliest peaches, but no fruit trees (temperate) flower as early as the earliest peaches.

However, Flavor Supreme pluot produces fruit successfully in about two or three years out of five years in my experience, depending on freezing temperatures. The same is true of Earlitreat peach. It is even worse for January flowering citrus.

Q: We had our 45-year-old olive tree trimmed in November 2022 by professionals. It did not flower this year. Can you tell me anything about the loss of fruit? Of course, we are wondering if it is well and what we can do at this point.

A: Olive produces flowers on last year’s growth, so any time you have it pruned thoroughly, the tree will produce very few flowers or no flowers the following year. Don’t prune it this year, and it will return to flowering. If it was pruned heavily, it may take two years to regrow and start flowering again.

I helped direct the pruning for a professional tree company on olive trees in the past. The same thing happened. The owner had a very old olive tree and wanted it to start producing fruit. The tree was pruned every year, and it produced very little fruit every year.

In this case, I told the pruning crew to just prune problem areas but leave most limbs unpruned. It produced fruit in those areas that were not pruned.

There is a shoot-to-root ratio as well. This has to do with how much was removed. If a lot was removed (pruned), then the pruned top is not in balance with the roots if the tree had healthy roots.

Let it grow. Some trees that are pruned a lot will skip a year or two until they start fruiting again. If the tree is “happy,” the top of the tree needs a chance to catch up to the roots before it starts flowering and fruiting again.

Q: I have a Katy Apricot tree that was planted about two months ago. Some of the leaves (especially the new ones) are curling/cupping, and there are some small rust-like spots on some of the leaves. The older, larger leaves are not curling/cupping.

The tree is on the east side of our house and is shaded by our house from the hot afternoons. I looked for aphids but didn’t see any. Any idea as to what might be causing the leaves to curl/cup? Should I do a light spray of Spinosad just in case aphids are the problem?

A: My first thought, like you, were aphids, but you are inspecting the leaves, so I don’t think that is the problem. That is the most common issue this time of year that causes deformed and sticky leaves. You should be using a dormant oil (horticultural oil) every year when you spray in the winter (or just after planting), and that will take care of any overwintering aphids if there are any. It reduces an aphid problem, which in turn reduces an ant problem.

I think it was overnight freezing damage. New leaves are a bit more tender than older leaves, so they are subject to damage. Typical damage seen with a light freeze is the edges of leaves damaged from freezing temperatures. The freezing problem is gone, and your tree looks very healthy. I would not worry about it.

I noticed you did not have a 2- to 3-inch layer of wood chip mulch on the top of the soil to the canopy edges. This layer will decompose as it adds nutrients to the soil, control annual weeds, save water and keep the soil cooler. It will not control bermuda grass.

You do not need Spinosad or any spray at this time. Horticultural oil just before new growth begins is a better choice.

Q: I just bought a Kadota fig and want to make sure I put it in the best spot before I plant. I was thinking about putting it on the west side of the house in a strip that is about 7 feet wide between the house and retaining wall. The neighbor’s single-story house beyond the retaining wall is elevated about 5 feet above ours. Is it going to be too hot there? Will it do better in-ground or in an oak half-barrel?

A: The best thing to remember about figs of any type is their water requirements. That includes Kadota fig.

Think of figs as oasis plants; they are not a desert plant like a Joshua tree. They can get big (30+ feet), so they are not suitable for containers such as oak barrels.

Container plants are smaller than figs, usually 12 to 15 feet tall. No, you can’t prune them to make them smaller regardless of what you are told. Fig tops will take quite a bit of pruning, but their roots are harder to prune. It is easier to keep fig trees smaller by managing their water and pruning the top.

They will trick you because their need for water to produce stems and leaves is less than to produce fruit. They start producing a crop of figs after the leaves and stems start growing. To produce fruit, they need as much water, watered the same way, and soil improvement, as any other fruit tree.

Another thing that might trick you is their second crop of figs — their so-called main crop. This crop starts coming on when it gets hot, so they need to be watered three times a week, 18 to 24 inches deep, to give them enough water.

Figs like the heat so the west side is not a problem for figs if given enough room for growth. Leave the lower limbs to shade the trunk and make it easier to harvest the fruit.

Q: I was thinking about getting a Lettuce Grow hydroponic tower to grow some veggies and herbs. I think it’s too hot shortly for anything but maybe some herbs.

Which side of the house do you think would be best suited? I was thinking about the south/southwest small patio, which has a short overhead slated cover. What do you think?

A: Hydroponic growing of vegetables and herbs is best done with leafy greens; that’s why it is called a Lettuce Grow hydroponic tower. Hydroponics can be done with fruiting vegetables as well, but it is a bit trickier. I would suggest starting with vegetables and herbs in either a traditional garden or raised bed and learn how to grow them in our climate first before buying a hydroponic tower.

South facing is the traditional side. Leafy green herbs and vegetables do best with about 30 percent shade. The leaves get thinner and more delicate. Herbs and vegetables that produce fruit that you eat, it doesn’t matter as much.

Bob Morris is a horticulture expert and professor emeritus of the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.