I've saved a large number of documents I've written about common maladies faced by hobby growers. I hope the info helps you sort things out.

Dishsoap/ detergent’s effect on plants varies with the mode of exposure. Dawn, Palmolive, Joy, ...... dishsoap, as an example, are each and all a mishmash of chemicals, at least eleven of which are phytotoxic. If the top of the plant is sprayed thoroughly with even mild detergent solutions such that all surfaces including leaves are covered, the detergent can easily dissolve the protective coating of cuticular wax on the leaves of the plant, causing abnormally high rates of water loss and possible necrosis of all or part of the leaf. Cuticular waxes prevent leaves from drying out, and help stop pathogens from attacking the leaf. Strong solutions will even dissolve cell membranes, causing death of the cells.

If a detergent solution is used as a soil drench or makes its way into the soil as a consequence of over-spray or run-off, the effect on roots is immediate. Because one of the main function of roots is to absorb water and nutrients dissolved in water, they lack the waxy protective coating that leaves employ. Detergent solution in contact with root cells can quickly dissolve the lipid membrane surrounding cells, killing the cells and inhibiting water/ nutrient uptake. Hair cells growing as appendages off larger roots do the lion’s share of assimilating water and nutrients, and these very delicate cells would be the first casualty of any detergent in the root zone.

There are widely available insecticidal soaps, designed to be used topically and made mixing potassium with only long chain fatty acids, carefully selected and specifically formulated to be safe for mammals & birds, death on most insects they contact, and most important, safe for plants. If you need something "soapy", it would be much better if you selected a product intended for use on plants than one intended for other purposes.

Most growers unfamiliar with how water behaves in container media are prone to repeating the title mantra. But let's look at some facts. A saturated or partially saturated medium is limiting in a number of ways.

Roots need an ample supply of oxygen in order that roots can function normally. Saturated soil surrounding roots limits oxygen required to drive root function, thereby impairing root efficiency and possibly setting the stage for any of a number of fungal pathogens that thrive in anaerobic (airless) conditions.

Soil saturation limits gas exchange, so waste gases like methane and CO2 in the root zone are less able to leave the soil, also limiting root function

Soil saturation kills the fine roots that do the lion's share of work involving water uptake and nutrient distribution. When this occurs, chemical messengers tell plant central injury to the root system has occurred. Top growth stops immediately, because root growth always precedes top growth – the top will not grow if the roots cannot support the growth with water/nutrients. The plant is then forced to regenerate dead roots, using energy which otherwise would have been devoted to additional top growth, keeping the plant's systems orderly, keeping the plant wearing a 'healthy glow', and improving the plant's ability to defend itself. In short, the wasted energy would have kept the plant looking/ growing better, and healthier.

If a pot is 10” deep, the top 2” can feel completely dry to the touch, even while the bottom 6” is 100 saturated. That means 60% of the medium would be fighting you tooth and nail for control over the plant's vitality …… and this is the point at which you should water again? Does that sound reasonable? We don't care even a whit if the top 2" of the soil are dry. Roots there are largely plumbing and anchorage, with essentially none of the fine almost microscopic roots that do the lion's share of the plant's heavy lifting.

Ficus species are all good at retaining water in their roots in case of drought. That doesn't mean you should test them to see what they'll tolerate, but it does mean you can and should let the soil dry down so you can only detect moisture (by using a 'tell') in the bottom inch or two of soil. Imagine how much 100% saturated medium lies at the bottom of that pot.

Too, the shape of the pot will make it impossible to pot up or repot w/o destroying the pot because you won't be able to remove the plant. Woody plants REQUIRE regular repottings which include removing all soil, pruning roots, and reestablishing the plant in another or the same pot in fresh grow medium.

Using a 'tell'

Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant.

Watering in small sips leads to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor.

In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water.

Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'.

One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue.

This Overview of Good Growing Practices should be helpful.

Al

Very informative. Thank you for thoroughly explaining the proper watering technique and the cause and effect that over as well as under watering have on these particular plants.

..... and thank you for the kind words!

Al