Ask Mr. Smarty Plants

Okay, let's get organized. You have three plants that are not blooming, so we will look at them one by one and see if there is a common denominator.

1. Yellow bells - in our Native Plant Database this is listed as Tecoma stans (Yellow bells)  which is native to Arizona but not to Maricopa County, according to this USDA Plant Profile. It is in the Bignoniaceae or trumpet creeper family, and this is ordinarily able to start blooming fairly early in its life cycle.

"Growing Conditions

Water Use: Low
Light Requirement: Sun , Part Shade
Soil Moisture: Dry
CaCO3 Tolerance: High
Drought Tolerance: High
Cold Tolerant: yes
Heat Tolerant: yes
Soil Description: Well drained, rocky, limestone, sand, and loam soils
Conditions Comments:  Yellow bells is drought tolerant and Southwestern varieties are adapted to monsoon rains with dry spells between. They may flower better if such conditions are emulated in planned landscapes, so allow ground to dry out between waterings."

2. Orange Jubilee - Tecoma alata, article from Arizona State University. This is native to Peru, but apparently does okay in North America. Needs full sun.

3. Bougainvillea - Native to Brazil. Article from Aggie Agriculture on Bougainvillea. "If your bougainvillea is not blooming, it probably is not receiving enough sun or fertilizer. These plants thrive in the tropics in areas of low rainfall and intense sun and heat."

So we have two plants in the same genus (Tecoma), one native and one not, so we don't know what effect the soils have on the blooming of the plant. Bougainvillea is also not native to North America.

About the best we can do is refer you to the links we have given on the three plants, and then give you what are more or less our generic rules on plants that are not blooming. First, you will note that all three need full sun, which we consider to be 6 hours or more of sun a day. Second, Tecoma stans (Yellow bells), at least, does not need all that water you seem to be giving it. If it is not getting very good drainage in the soil, so the soil can dry out between waterings, the roots may be drowning. Cut back on the water. Third, a very frequent reason for non-blooming is that they are getting too much fertilizer, especially the high nitrogen fertilizers meant for lawns. Nitrogen encourages a lot of green leaves, which is what you want on lawn but not on flowering bushes. The last thing is the sun and heat, which all three plants seem to thrive on.

Conclusion: There is something about the culture of the plants themselves, food, water, sun or soil that is probably inhibiting the flowering. Try to figure out what you have changed that might be causing it. Since we recommend only native plants, we feel that the fact that none of the plants are native to where you are growing them could mean there is some incompatibility with the soil.