Fig trees need ample water while producing fruit

Q: I have Brown Turkey figs that are 10 and 12 years old. This year the fruit is large, but as they are lightly purpling up, the skin has wrinkled, and the fruit is very dry within. Some were black, like smut, but mostly dry, and lumpy.

A: Check the amount of water your figs are getting. Most figs should be watered twice a week right now. Fruit trees should not be short on water while they’re producing fruit.

We are quickly approaching temperatures (and wind) that require watering figs three times a week. The higher temperatures demand more water for production to continue.

It’s true that many plant leaves close their stomates (most water loss is from transpiration) during the night. But that is only part of the problem. Evapo-transpiration accounts for evaporation from the soil as well as transpiration mostly from plant leaves. Water management must account for both.

This is why covering the soil with mulch is so important.

The next irrigation occurs when water from the soil reaches about 50 percent, or leaf scorching and branch/twig death might occur. The water in the soil is like the gas tank of a car, but only let the tank get half empty before filling it again with an irrigation.

Figs produce two crops of fruit: an early crop (breba) and a later (main) crop. Early fig production, in my experience, is less affected by a lack of water than the main crop.

Q: Will this heat damage plants?

A: Most likely not. If the plants have been in the ground for a few years, then they are acclimated. The problems come from those that are recently planted or planted during the heat. Flowering plants need six to eight hours of sunlight every day. Nonflowering plants can get by with less.

Your choice, when they are planted, is whether these plants should get morning sun (primarily east or north sides) or afternoon sun (south or west sides). If they are growing successfully in a location you’ve chosen for them, then don’t move them.

Q: My son has a lathe and does a lot of turning of bowls and other similar items. This creates a lot of wood dust. I was wondering if the wood dust can be used to fertilize or mulch the garden? I know you have said to use small chips for mulch. It seems to me that the dust should be good for something rather than throwing this out.

A: It’s better for your soil, physically and chemically, to use wood particles in a variety of sizes rather than adding sawdust alone. As this material decomposes, it adds organics, which can be good. It goes without saying that this is not plywood or particle board sawdust — that would add glues to your soil and is better off in a landfill.

You can use sawdust, but be careful. Adding sawdust to your soil can cause plants to become yellow from a lack of nitrogen as this sawdust decomposes. I would mix it with high nitrogen fertilizer such as a tomato or lawn fertilizer.

Be careful of dumping large amounts of dust of any type on the soil surface in one location. It can alter the soil physically. This dumping can suffocate plant roots and change a soil’s physical property so that air exchange decreases.

Q: We are encouraged not to wash pool filters in our driveway and allow this water to wash down the street. My question is, will chemical residue from the filters hurt plants and shrubs if the filters are washed in the yard?

A: My biggest concerns are the level of chlorine it might contain and the dust particle size. Both of these can affect plants if applied over and over. Doing it only once probably will not have much effect on landscape plants.

Regarding the chlorine levels, if you can remove the pool cover the day before you clean the filters the levels of chlorine will be lower.

All plants need chlorine. It is essential, but not at the levels needed for killing algae. Anything you can do to lower the chlorine levels a day or so before using these filters, the better it will be for landscape plants. Sunlight and evaporation minimize the effects of elevated chlorine levels.

The next issue is the particle size of the filters. Sprinkle it around plants. Avoid putting it in a large glob on top of the soil.

Q: A few days ago, one of my trees turned almost overnight. The one on the right remains healthy, the one on the left not so much. They both get the same watering and feeding regimen for the last six years. Any suggestions?

A: The installer would usually put about four emitters a few inches from the trunks of these trees when planted. The trees will outgrow this number of emitters in several years. Six years is kind of pushing it.

After that, more emitters need to be added because the tree needs more water now than when it was smaller. My guess is that the tree getting enough water is getting it from somewhere. Plants don’t respect boundaries. Look at your neighbor’s yard or if plugged emitters were used around the tree not getting enough water.

What to do? Start with the easiest: Check to make sure all of the emitters are delivering water. Next, water both trees with a hose once a week and see there’s any recovery; it should take two to three weeks. If you see a good response, add more emitters to the trees so they get more water.

Next, inspect the trees. Push on the tree hard and see if the base of the tree wiggles in the soil. Wiggling or movement at the base, causing the soil to move, indicates root damage or failure to root into the surrounding soil. If this is the case, the tree needs to be replaced. This problem can’t be fixed.

Inspect the trunk for damage on the west or south side. Damage indicates sunburn and possible damage from borers. In both of these cases, the weakest tree may need replacement.

Bob Morris is a horticulture expert and professor emeritus of UNLV. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.