Q: I am interested in growing strawberry guava in southwest Las Vegas and want to know if these are good choices. Can you tell me what fruit and evergreen tree varieties have the best chance to survive in our desert?
A: Our desert is a great place to grow strawberry guava except for our cold winters and occasional snowfall. The fruit grows on new growth from a small tree, 10 to 20 feet tall. If they are kept warm or from freezing, then strawberry guava will work here.
My suggestion — if you plan to grow them here — is to pick a non-windy place (windy locations make temperatures colder in my opinion) in your landscape. This protected location should get at least six hours of direct sunlight.
Protect them from the wind with a constructed wind barrier or other plants. Not a solid wall. Solid walls create dust devils. Pick a location that is either on the east side or north side of a building or wall, not hotter locations found on the west or south sides. Plant them at least 5 feet from a wall or building.
Make sure the planting hole is about 3 to 4 feet wide and dug as deep as the roots. Amend the soil with compost or use composted soil when planting. Make sure the soil is wet, not dry. Plant in a hurry.
Cover the soil with a 3- to 4-inch layer of wood chips when finished. Stake the tree after planting. Protect it from rabbits or other vermin if they are seen. Applied water should wet the soil to 18 inches deep to at least half the area under the tree canopy as it gets bigger.
Avoid planting seeded types but instead pick pink or red varieties such as Homestead, Barbie Pink, Hong Kong Pink, Blitch and varieties recommended by the University of Florida that have proved successful there. Green varieties are picked before they are ripe, and red or pink varieties are picked after they ripen. Guava is a climacteric fruit, so it will ripen further after it is picked near ripe.
Q: I am hoping you can tell me what is wrong with my star jasmine. These plants are approximately 20 years old. The wall they are growing on is north facing. I have pulled the rock mulch away from the base. I mix in compost to each plant every spring when I fertilize. Could it be the irrigation is too close to the trunk?
A: Without looking at the pictures I was expecting them to be yellow. That’s usually what happens to star jasmine in rock landscapes. Your addition of compost to the soil is keeping them green and healthy.
Bare stems on older growth can be a natural occurrence. I don’t think it is in your case. It is possible if the water applied is too close to the stems and it is being applied too often, then you can end up with bare stems. It is best if the water is applied 12 to 18 inches from the trunk (stems, base) of the vine.
Water, when it hits the soil, spreads out. In soils that are very sandy this distance might be 12 inches from where it is applied. If the soil has a small amount of clay in it, then the spread is about 18 inches from where it is applied. In soil with lots of clay — most of the soils in Las Vegas do not have that much clay — water can spread out from where it was applied from 4 to 6 feet. A happy medium is 12 to 18 inches from the stems or trunk.
Be careful of applying water too often. It can keep the soil wet too long. That can result in leaf drop followed by bare stems.
It is always best for plants that have deeper roots (like your jasmine vine) to apply water less often. Vines like star jasmine are deeper-rooted, like medium-sized shrubs. Water should wet the soil 12 to 18 inches deep each time is applied. Water your vines like they are medium-sized shrubs.
What can you do with bare stems? Cut them back no closer than 3 or 4 inches, and they will send out suckers that will fill in open spaces if the vine is alive.
Q: I planted a peach tree late last winter, but before I could protect it, the rabbits began chewing on it a bit, not all the way around just a few spots. I’m not sure if borers have gotten to it. Do you think it can be saved or is it time to pull it out?
A: Most trees, including fruit trees, can lose about half of their bark by chewing and still survive. If it were me I would tally up all of the damage and if this damage is less than 50 percent then it should be fine. You might lose some branches that are severely damaged but the majority should survive.
Protect the rest of the tree from vermin damage and don’t worry about it too much. The damage will heal on its own. If you want the tree to recover from damage faster, make sure it is getting enough water and fertilize it at least once each spring.
Q: I’m starting to think about springtime approaching and the need for fertilizing. Do you have an iron fertilizer you recommend? We added the compost you suggested, but I want to make sure we are on top of the iron needs of our plants.
A: The iron chelate I like to use is a bit more expensive. The reason I recommend it is because of its stability in both highly alkaline and highly acidic soils. It works regardless of the soil or its alkalinity.
The chelate I like to use is EDDHA iron chelate. It comes under several names, but as long as the iron is bound to the EDDHA chelate, then it is what I recommend. Other types of chelates and iron fertilizers stop working in highly alkaline soils.
If you are adding compost to compost-amended soil, then any chelate or iron fertilizer will probably work whether it is iron sulfate, brake filings or iron chelates such as EDTA or DTPA This is because soils that have compost added to them usually are not strongly alkaline. The compost additions, with water, usually lower the alkalinity of the soil.
Any iron fertilizer or chelate must be applied and mixed with the soil in the early spring: sometime soon after Feb. 1 in our Las Vegas climate. Soil applications get less effective as the growth begins to stop.
By mid- to late summer you must switch to iron fertilizers applied as a liquid to the leaves for acceptable results. Iron fertilizers applied wet to the leaves (foliar applications of iron) are not as effective and may need to be applied to the leaves of trees and shrubs several times to work.
Q: I have a very hot location I want to plant. It’s facing west. I had a Pink Lady apple tree in that spot, but I think it was just too hot for it. It died in a couple of years. What do you suggest?
A: Hot locations are tough. From the look at the picture you sent there does not seem to be much air movement. Just a lot of reflected heat from high walls. In my opinion, that area will get super cold in the winter too. I would put a waterproof recording thermometer in that area to track temperatures both during the heat of the summer and cold of the winter.
Not having much air movement can have both good things about it and bad things. The main advantage of that hot location is wind blockage.
In spots like that, I would recommend first to cut back on reflected heat. Cover this area with about 50 percent shade cloth until the tree gets grows enough to cast its own shade on the walls and soil. While shade cloth is provided, grow a deciduous vine that likes the heat, such as catclaw vine, so that it covers the wall.
Covering the wall during the heat of summer reduces the reflected heat in that area. Provide shade for that spot for about four to six years if the tree grows quickly. The fruit tree should start producing in the second to fourth year depending on what is grown.
Let the temperatures recorded there dictate what to plant in the future. Personally, I think apples, pears and other related fruit trees may be a poor choice for that spot because of excessive heat. Most citrus, except Meyer lemon, grapefruit, kumquat and tangerine may work if the winter temperatures are warm enough. Apricot or pomegranate are better choices.
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.