With lots of sugar, ornamental plums make good jam

Q: We have a flowering plum (supposedly ornamental) tree in our front yard. This year, it is covered with small walnut-sized plums. Are these edible? I am envisioning plum jam if they are edible.

A: Yes they are! These plums are sour but have great flavor so use lots of sugar and follow your favorite plum jelly or jam recipe.

By the way, the plums also can be used to make wine or infused into vodka or grappa with sugar and let it stand for three to four months or longer. I was put to shame by one of our local winemakers who brought me some of his ornamental plum jam and another with his infused vodka.

Here's a good recipe to try.

Ornamental Plum Jelly

4 cups plum juice

1 cup water

6½ cups sugar

1 box Sure-Jell

1 teaspoon butter

Because the plums are so small, wash and put them into a pot and add enough water to cover them. Boil them for 20 minutes or until the skins pop. Mash them with a potato masher. Continue to cook for another 10 minutes. Let cool. Strain mashed fruit through cheesecloth or jelly bag to get the juice.

Add Sure-Jell to filtered juice and extra water and bring back to a rolling boil, stirring all the time. Add butter and all the sugar and boil for one minute. Skim and pour into jelly jars.

Q: A friend of mine has recommended that I contact you regarding a problem I've got with a newly planted garden in my backyard. These beetles are devouring my strawberries and I'm even seeing them on my other veggies in the same planting area. I tried the water, soap, baking soda and cayenne pepper spray solution but it's not seeming to make much of an impact, if any. I really don't want to use pesticides.

A: What you have is most likely one of the vine weevils. Because it is on strawberries I would like to think it is the strawberry vine weevil, but there are other vine weevils as well. Regardless of the name the problem and controls are similar - and difficult.

Probably one of the more effective ways is going to sterilize the soil. This can be done without chemicals. This will require you to remove the plants from their home, wash them thoroughly and replant them in soil that has been sterilized through solar sterilization. This is a bad time of year to do this however. You could do this in the fall.

You will sterilize the soil by tilling or digging the soil so that it is loose to a depth of 12 inches. Water the soil. Place clear plastic over the top and seal the edges with soil and rocks so the wind does not blow it open.

Leave it covered so that the soil "cooks" for two hot days. After two hot days you can uncover it, let it cool and plant it again with clean plants. Use clean mulch that is free of critters, as much as possible.

There are baits you can buy but the bait must say it controls pill bugs and sow bugs, not just snails and slugs. The bed will get infested again and you will have to go through the same scenario to clean up the bed.

There are some insecticides you could use but check the label to make sure they can be used on fruit and see how many days you have to wait before you can pick the fruit after you apply it. This is called the "re-entry period" and it is sometimes on the label.

Q: I have four Hawaiian tomato plants in containers, all producing tomatoes. On one plant, the leaves on the lower branches are turning yellow. The plant appears to be healthy, having several flowers and small fruit forming. I fertilized all four plants two weeks ago with Miracle-Gro and was planning to fertilize in two-week intervals as suggested on the product container. What can be done to prevent the yellowing of leaves on the other three plants and resolve the present problem with the one plant in question?

A: There could be several things going on. My first reaction was a lack of nitrogen fertilizer until you told me you were using a fertilizer on a regular basis. When plants don't get enough nitrogen fertilizer the older leaves can turn yellow and die.

You also can look at how much new growth there is since nitrogen also is responsible for stem and leaf growth. If it is not growing and putting on new growth, then this also can be an indicator of a lack of nitrogen.

Watering too often and keeping the soil too moist also can cause yellowing of foliage.

So if you have mulched the soil and are watering frequently, then this might be a potential problem.

Some soil amendments, if they have not broken down completely, can cause yellowing but this is usually compensated by using fertilizer high in nitrogen. Also, poor-grade composts can cause yellowing so try to avoid very inexpensive composts and soil amendments. Good soil amendments are expensive unless you make your own.

If the soil is native desert soil that has been amended with compost or soil amendments, salts can cause yellowing of leaves. There are lots of natural salts in desert soils, frequently at levels too high for most of our landscape and vegetable plants. If your soil is fairly new, it make take a couple of years of compost and growing to get it into good condition.

Salts are removed by leaching or watering the soil with lots of water and letting it drain over and over in repeating cycles. Salts dissolve easily in fresh water and the draining water carries dissolved salts from the soil to a depth below the roots of the plants. If you use composted native desert soils, you should always leach the soil prior to planting.

So look at your soil modifications, how you are watering and whether you have leached the soil or not. If, after this, you think there is still a problem, you might consider replacing the soil.

Bob Morris is a horticulture expert living in Las Vegas; he is on special assignment in the Balkh Province, Afghanistan, for the University of California, Davis. Visit his blog at xtremehorticulture.blogspot.com.