My oleander is just beginning to bloom. Can I prune for shape without hurting the plant?
The best time to prune Oleanders is right after they are done blooming.
Here is an article that will help you.
https://www.gardeningknowhow.com/ornamental/shrubs/oleander/pruning-oleander-shrubs.htm
Can an Oleander plant be divided and, if so, when is the best time of year? I have an Oleander that could be divided into two parts.
I do not think that oleanders can be easily divided in this manner due to their dense root systems. You can, however, air layer oleander plants to get multiple plants off of one. More information on layering can be found at the following links:
https://www.gardeningknowhow.com/garden-how-to/propagation/layering/air-layering-plants.htm
https://bit.ly/1yet0bS
Oleander in zone 4 at winter outside has all leaves black or silver (was covered with paper and plastic bags). I planted oleander in zone 4, but It was covered on ground, and all over. Tree looks dead, leaves are black and silvered, some white spots from water on a tree by itself. Is there any way to bring it to life, or it is impossible to keep such tree outside (I don't have any space inside) and give it up? I love this tree! But winter is too harsh here in Michigan.
Oleanders are considered hardy USDA plant hardiness zones 8 through 10, but they are sometimes damaged by frost in zone 8. That being said, I think zone 4 might be too big of a stretch for your oleander to survive.
I would recommend reading the following article about cold damaged plants and apply some of the knowledge there. You might be able to revive it, certainly worth a try, but be steeled for the possibility that it won't recover:
I want to grow more oleander trees. Will they grow from tree trimmings?
Here is a link, from the International Oleander Society, that will tell you how to propagate your oleander tree from cuttings
http://oleander.org/culture/
For more information on oleander, please visit the following link:
https://www.gardeningknowhow.com/ornamental/shrubs/oleander/
Is there such a thing as a blue Oleander? I have seen pictures of these plants but getting information is proving quite elusive.
I have not been able to find any 'blue' Oleander cultivator.
It would seem that the 'blue oleander' is mythical.
Our oleanders all grow to the side as if the wind has blown them all like that. They all are that way. Should we tie them up? We live in Houston, Tx not in a windy area. What do we do?
Do you suspect that the plants have shifted in the soil?
Can you pull the shrub to an upright position?
If they shrubs can be pulled into a more normal position, I would stake the plants.
Use protective clothing whenever working around Oleanders, as all parts of plant are poisonous.
Here are some links with more information.
https://www.gardeningknowhow.com/ornamental/trees/tgen/straighten-tree.htm
https://www.gardeningknowhow.com/ornamental/shrubs/oleander/oleander-growing-tips.htm
https://www.gardeningknowhow.com/ornamental/shrubs/oleander/pruning-oleander-shrubs.htm
I bought 2 pink oleander shrubs about 2 years ago and they have never flowered. I have given them fertilizer and kept them watered in the dry weather. What am I doing wrong?
Fertilizer is generally only recommended the first year they are planted to help them become established.
They likely have too much nitrogen to bloom. Excess nitrogen will cause lots of green leaves and no flowers.
You can give the plants some phosphorous to promote flowering.
If you still have no flowering, you will want to do a soil test to correct the soil.
Here are some links with more information.
https://www.gardeningknowhow.com/ornamental/shrubs/oleander/oleander-growing-tips.htm
https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/phosphorus-plant-growth.htm