Tomato varieties have pluses, minuses in desert climate

Q: I found a tomato variety that’s doing great in my garden called Heatmaster. I can tell it’s a determinate type because it’s loaded with tomatoes right now, pretty much all at the same time. I’ve read determinate types die after the tomatoes ripen. Is that true? Can I root it from a branch and plant it next month for a second crop even though it’s a determinate type?

A: Yes, Heatmaster is a determinate type regarding how the plant grows and produces tomatoes. But be careful. You can root this tomato from suckers, but creating new plants from suckers is difficult to do in this climate. Try it and see how you do, but it can be done.

Determinate and indeterminate tomatoes have their pluses and minuses. You can usually tell if it’s determinate from where the fruit is produced. Determinate tomatoes produce their fruit at the ends of stems while indeterminate types typically produce along its stems. Most complaints about heat-tolerant tomatoes like Heatmaster is regarding their bland taste.

Determinate types of tomatoes usually do not die after they set fruit. Tomato plants are tropical perennials. Death is typically from disease or problems associated with high temperatures. A determinate-type tomato is good to have in the garden, but indeterminate types work as well. Just handle them differently.

So-called heat-tolerant tomatoes like Heatmaster, Phoenix (also determinate) and others were bred for warm southern climates and not for the hot desert. They might set fruit at temperatures a few degrees warmer than normal but not when the air temperature gets into the 100s.

If you have cool weather during fruit set, then any tomato will set fruit, including heirlooms like Mortgage Lifter and Brandywines. That’s why you may have good luck with hard-to-set tomatoes some years.

Some of it is the “luck of the draw” as far as weather goes, but a favorable garden environment that limits wind and wide temperature swings helps. Be careful about relying on one year of good production to make future buying decisions.

Plant several types of tomatoes rather than focus on one variety. Cherry, grape and pear tomatoes are the easiest to grow and set fruit the easiest. Most of these are indeterminate types.

Probably the next easiest is the plum type tomatoes like San Marzano and Roma. For some reason, disease-prone Early Girl (indeterminate), hybrid Celebrity (bushy but indeterminate) and even Burpee’s 70-year-old Big Boy (indeterminate) are good performers in our finicky desert climate.

Make sure there aren’t other reasons for a lack of fruit set such as low humidity and a lack of pollinators. Plant herbs like rosemary, basil, thyme, mint and fennel to attract pollinators. Put out water in flat trays and clean often. Bees visit many of the flowering herbs and clean water they can haul back to their hives when tomatoes start flowering.

Q: One of my pomegranate trees has very pale leaves on one of its branches and dark healthy green leaves on the others. I put nitrogen fertilizer on both sides of the tree plus we did put a balanced fertilizer on it and some compost.

A: When one branch of a plant is dramatically different in color while the other branches are healthy, it means that whatever is causing this problem is at the bottom of that sick part. Because borers are not common in pomegranate, the cause is most likely man-made or a disease problem.

Look at the main stem just below the yellow leaves. The leaves below this point should be healthy while the leaves above it should be sickly. If the entire stem is sick, then look at the stem just above and below where it enters the ground.

If the entire stem is sick but alive, then I am guessing it is damage below this area from tools, machinery or disease. If the stem is totally dead, then it involves a lot more guesswork.

Mower damage, if planted in a lawn, can cause this type of damage. This type of damage makes the plant worse during hot summer months when everything is more stressed. Line trimmer damage can cause the same type of damage as mowers. Diseases like collar rot that choke the stem, when the plant is kept moist all the time, can cause the same visual damage as mowers and line trimmers.

What to do? If there is mulch surrounding the stems or anything that can act like a sponge and hold water, pull it back and away from the stems 6 to 12 inches and let this area dry out.

Never water daily. Always give the soil a chance to dry out before watering again. The only areas of a landscape that need daily watering are lawns, vegetable gardens and flower beds.

Whatever the cause, this yellowing stem probably should be removed. Sanitize your lopper, pruning shears or saw with alcohol and remove the stem at ground level. It is best to do it in the fall or winter, but you can remove it now on pomegranates with no problems.

Q: Several years back my father and I planted two Raywood ash trees in each of our yards. Now both trees have longitudinal gashes along the stems that kill many of the smaller branches. Last year I found the same problem on one of my rose bushes. Per the recommendation of the nursery, I sprayed a systemic containing imidacloprid and clothianidin on the trees

A: This sounds like egg-laying damage by the Apache cicada, those high-pitched insects you hear buzzing in about July. The insecticide you are spraying will not correct this problem, so stop using it.

Apache cicadas make that buzzing noise so they can mate. Once they have mated, the female lays eggs in a slit she creates on the branches. If these slits cause enough damage, the twig dies.

The eggs then hatch, and the insect drops to the ground where they burrow into the soil and feed on plant roots. Lots of different trees are favorites, your ash trees (sounds like the roses, too) being among them.

Spraying the tree with an insecticide, or drenching the soil with one, is not a good idea. I think your best bet is to give your trees as much chance to heal themselves after the damage is done as possible.

Their best chance of healing from this type of damage is the presence of fertilizer in the soil and adequate water during the heat. Of course, scaring these insects off to other trees during mating time would help.

Make sure these trees are fertilized in the spring and bump up the amount of water applied when you start hearing the buzzing noise. You might even try watering every other day during this period to help the tree recover from cicada egg-laying damage.

Q: A couple of years ago our builder planted a multitrunk Chilean mesquite tree in our side yard which borders a street. The tree is planted 12 feet from the house but is only 5 feet from a block wall. I am concerned this tree will become huge and its root system may disrupt the wall since there are several irrigated shrubs on the other side. I am thinking of removing it while it’s still young and replacing it with a tamer tree.

A: That’s a good call and very forward-thinking on your part. This tree will grow quickly to about 50 feet with an equal spread. If you are going to replace a tree, this fall would be the right time to do it.

Remember, planting smaller sized trees will overtake planting larger trees in one or two seasons of growth. No reason to buy larger trees unless you need immediate impact from them.

If your home is a single-story home, consider two small desert trees to replace a single big Chilean mesquite. Plant them a distance apart equal to their mature height and about half their mature height from the home.

If this tree area is on the south or west side of the home, make them winter deciduous for winter heat gain. All you want are trees large enough to shade the walls and windows during the summer.

Tree roots follow the water. Roots will grow wherever you apply water, or they find wet soil. Keep applied water 3 feet from the foundation of the home and the wall.

It might not be a bad idea to install a root barrier between the trees and the home’s foundation and block wall. But watering lengthwise and parallel to the home will encourage the roots of the newly planted trees to grow in that direction as well. Tree roots do not have to grow in a circle under the tree.

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.