What is the process to planting Feijoa trees? I have just purchased two Feijoa trees.
The following link has a lot of information: http://www.hort.purdue.edu/newcrop/morton/feijoa.html
I have three shrubs that I purchased at different times, all planted with southern foundation exposure. I have banana trees thriving within three feet of these shrubs. And yet, over ten years, no blooms on any of the three plants, ever. Not one. The plants grow annually, but fail to flower at all. I have twice emailed the seller, One Green World, which is a highly reputable nursery, and have not gotten any sort of answer. Suspect they are stumped as well. I live in Everett, WA which hovers pretty close to a zone 8 for climate, and have an extensive variety of plants which are successful long term. Not a beginner :-)
Since you have never had blossoms or fruit, it would seem the plants are not quite happy in the environment.
Feijoa will grow in full sun or some shade locations. They can be grown in several soil conditions but do need a slightly acidic soil.
They do not require much pruning and typically will do well with just rainfall irrigation.
Do you know the varieties that you have planted? A self fruiting variety that has done well for home gardeners is 'Coolidge'.
The plants actually do need a brief period of cooler temperatures in the winter to set fruit.
I would suggest a soil test to help you determine what may or may not be needed.
Here is a link to refresh you on the care requirements.
https://www.gardeningknowhow.com/edible/fruits/pineapple-guava/feijoa-pineapple-guava-info.htm
What is some good methods for protecting feijoa trees from frost? As the fruit gets destroyed by frost each year
Be sure to use cloth and not plastic to cover the plants during the frosty nights. Remove during the day. Plastic will not allow the moisture that collects under the plastic to evaporate and will cause the plant to freeze to the plant. Cloth allows for evaporation through the material. If you have a lot of pots you could consider buying a smudge pot to keep the air walmer around the plants.
https://www.gardeningknowhow.com/edible/fruits/pineapple-guava/feijoa-pineapple-guava-info.htm
The article below is about winterizing Fig Tree's but the technique would apply in your case.
https://www.gardeningknowhow.com/edible/fruits/figs/fig-cold-protection.htm
My Feijoa tree’s leaves have black edge at the back. What is the issue? How can I treat this to make the tree come back to be healthy. Thanks a lot.
This looks bacterial! This will indicate that the area remains too wet for too long. It may take some heavier, copper based fungicides to do any good here. This, along with keeping heavily infected growth cut and disposed of away from the area, can help in recovery. Here are some articles that will help:
https://www.gardeningknowhow.com/garden-how-to/info/using-fungicides-in-garden.htm
https://www.gardeningknowhow.com/garden-how-to/info/what-is-copper-fungicide.htm
https://www.gardeningknowhow.com/edible/fruits/pineapple-guava/feijoa-pineapple-guava-info.htm