Cold-water rinse prolongs life of freshly picked plums

Q: I did what you told me to do to ripen plums from my tree and it worked but they were mostly still very tart. Why did you tell me to put them in cold water after I picked them?

A: When you harvest fruit in the heat of the summer, the fruit will have a lot of excessive warmth or heat. The heat is from the environment and the fruit’s respiration. We call this heat “field heat.”

This heat can be very destructive to fruit harvested in the field and can cause poor keeping quality. Therefore, we want to remove this heat from the fruit as quickly as possible after harvesting.

One way to do this is to plunge the fruit into icy water and get it closer to room temperature. After it cools to room temperature, you can let the fruit continue to ripen on the shelf, not in the refrigerator. They will get sweeter.

Q: As my tomatoes begin to “blush” red, they also get deep, vertical cracks in the skin unless we take them off the plant before the skin starts to crack. What’s happening and what should I do?

A: There are a couple of different kinds of cracks that develop in tomatoes. Cracks that form circles around the stem end are called concentric cracks.

Concentric cracks have more to do with the variety of tomato you’re growing. Many of the older heirloom types that didn’t make it to commercial production develop concentric cracks.

There were breeding programs for tomatoes specifically to eliminate concentric cracks and it was pretty successful. People did not like buying tomatoes with concentric cracks because they look ugly.

Fresh market tomatoes must be deep red and look perfect, even if they have no taste. Stay with some of the older commercial varieties like Early Girl or Jet Star if you want to avoid concentric cracks. A little bit more of the fruit has to be thrown out, but they are safe to eat.

Then there are vertical cracks or splits. These really have more to do with irrigation or rain. If you can maintain a steady supply of water to tomato plants so they do not become water-stressed during fruit development, you’ll have a much better chance of having tomatoes without splits.

Surface mulch helps a lot to regulate soil moisture and prevent splits. We may see splits develop in tomatoes after a rain. The fruit’s skin begins to mature as the fruit matures and then there is a sudden gush of water that the plant can take up in excess.

Just like popping a balloon, water goes into the fruit, the skin is no longer elastic and the skin splits. Again, the fruit is safe to eat, but you should harvest these fruits as soon as possible to prevent them from rotting or getting infested with bugs.

Q: My bottle tree is dropping its leaves and one side of the tree looks as if it is dying. It drops its leaves each year but this year it’s worse. It’s been on the same watering schedule as the bushes around it since we’ve been here. There are two sprinklers to that tree.

A: Leaf drop usually means a watering or soil drainage problem. If caused by watering, leaf drop usually means you’re watering the tree too often. Sometimes leaf drop can mean the tree’s not getting enough water at each irrigation.

The bottle tree, which originates from Australia’s dry desert climates, can tolerate poor arid or desert soils. It would normally do well in Las Vegas’ desert climate and soils if it is planted and watered correctly.

Bottle trees will benefit from having organic matter such as compost mixed in the backfill at the time of planting, but the soil underneath must have good drainage. Bottle trees won’t like getting watered frequently (multiple times during the week) or watered with small amounts.

These trees would prefer to receive water as they do in the desert: a large amount all at once then followed by a long, dry period. If these trees receive frequent irrigations and in small amounts they’ll struggle.

If you can get this tree on a weekly irrigation in the summer with a lot of water applied during that irrigation, it will be happier and perform better. You might want to consider adding more desert-adapted plants that receive water under its canopy. This will add more water.

Make sure the valve supplying the water is also watering other trees and shrubs, not flowers or a lawn. This will let you program your controller to wait longer between irrigations.

Many trees and shrubs that can tolerate watering on short, frequent irrigation cycles (multiple times during the week). But many desert plants, like this one, will not like it.

You might think that watering plants frequently would give them enough water because they are watered so often. But if you are only giving plants a tiny sip of water each time you water, this might also cause leaf drop.

Trees and shrubs need deep watering less often. Desert plants need the same amount of water applied as other trees but the water needs to be applied less often.

Q: We have scorpions in our neighborhood. In the past 17 nights, armed with an ultraviolet light, I have killed 205 scorpions around our house. So far we found only two in the house. Is there a better way to control the scorpions than getting out every night and hunting them down?

A: Scorpions move from the landscape and into homes in the fall to get warm. All of these critters are cold-blooded, so they will tend to migrate into warm locations when temperatures cool in the fall.

It may be little comfort to homeowners threatened by scorpions, but these guys do a lot to control insect populations; they are insect predators.

The good thing is they go after bad guys. The bad thing is they also go after good guys. They don’t discriminate between good insects and bad insects (from a human perspective).

There are different approaches for managing scorpions. One method is total extermination, such as you are trying. It will seldom be totally effective, but it will reduce their numbers considerably.

Another option is putting barriers down to keep the scorpions from entering the home. These also will not be fully effective, but they should greatly reduce the numbers of scorpions entering the home.

I generally recommend applying a barrier spray to the outside of the home, similar to the type of spray used to keep out spiders and cockroaches. Scorpions are easy to kill with insecticides. They are very susceptible to these sprays and often are killed when they eat other insects that have come in contact with spider and roach insecticides.

Any barrier spray application to the home’s foundation will work.

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