I am providing a fire safe area around my home which is in a wooded area. Is heavenly bamboo a firesafe plant?
Maintenance of the landscape is key, as well as choosing firewise plants. According to the University of California, deciduous plants have a higher moisture content and are more firewise as well as those without oily or waxy leaves such as evergreens. Heavenly Bamboo is a broadleaf evergreen and grows quickly so pruning is needed to maintain it. One publication rated it as risky.
Here are some articles that should help:
http://sonomamg.ucanr.edu/Firewise_Landscaping/Firewise_Home_Garden_Design/
https://www.gardeningknowhow.com/garden-how-to/design/lideas/firescaping-your-lawn-and-garden.htm
http://sonomamg.ucanr.edu/Firewise_Landscaping/Fire_Resistant_Plants/
I have sprayed for red spider. I have applied Neem oil.
Unfortunately, your photo did not come through. It sounds like a type of scale insect, which can be tough to remove.
https://www.gardeningknowhow.com/plant-problems/pests/insects/control-plant-scale.htm
I love nursing houseplants. This is a neighbor's cast off. What can I do to bring it back to life?
It looks like a Lucky bamboo that wasn't so lucky. They are usually grown in a ceramic vase with rocks and water, but you can grow them in soil, too. Trim it back a bit to tidy it up, which should encourage more growth. Here is more:
https://www.gardeningknowhow.com/houseplants/lucky-bamboo/pruning-lucky-bamboo-plants.htm
https://www.gardeningknowhow.com/houseplants/lucky-bamboo/growing-lucky-bamboo-indoor.htm
The tops of these 2 plants are dead. I want to use the one on the right to replace the one on the left which doesn't have anyt shoots. Do I have to do anything else when I plant the off cut ?
A cutting that large may not root. Usually you will want to take small cuttings (6-12 inches) for the best results. Eventually, a cutting can root and grow to be established.
This article will help to root cuttings: https://www.gardeningknowhow.com/ornamental/trees/tgen/how-to-root-cuttings-from-various-shrubs-bushes-and-trees.htm
Do I have to do anything to promote roots or can I just stick it in the ground ?
You should be able to cut that tall stem in thirds and have two cuttings to root. The stem left in the pot should send out new shoots.
Here is how to propagate from cuttings:
https://www.gardeningknowhow.com/ornamental/trees/tgen/how-to-root-cuttings-from-various-shrubs-bushes-and-trees.htm
https://www.gardeningknowhow.com/houseplants/dracaena/dragon-tree-plant-care.htm
I tried to follow the watering instructions but I'm afraid that I let it get too dry. It has lost all of its leaves and I wonder if I should cut back to get it to grow? It is in a 4" pot that it came with from the store. The pot does not hold any water so I have to leave it in the sink until the water drains out leaving the soil moist.
You can check to see if it is still alive by scraping off some of the bark. If there is green below it is still alive, if not, it is toast. Let the soil dry out between waterings. Overwatering is most often the reason plants fail.
Follow these care instructions and see if it regrows leaves:
https://www.gardeningknowhow.com/houseplants/dracaena/dracaena-houseplant-care.htm
https://www.gardeningknowhow.com/houseplants/dracaena/dracaena-plant-irrigation.htm
droop. None of the leaves are showing anything out of the ordinary and I don't think I've overwatered it. Is there anything you could suggest to try and bring it back to good health please?
I wonder if you meant to say leaf drop, not droop. According to the article below, some leaf drop is normal. Especially if you don't see signs of insects or envronmental concerns, I would just keep an eye on it. Here's more:
https://www.gardeningknowhow.com/houseplants/dracaena/dracaena-leaf-drop.htm
If you did mean "droop," I wonder if you have repotted in three years? Perhaps the plant is rootbound. If you need to repot, only go up one pot size to prevent overwatering.
https://www.gardeningknowhow.com/houseplants/hpgen/learn-more-about-repotting-houseplants.htm