Q. I have two, 7 foot tall oleander bushes about 8 feet apart. Can I turn them into trees by cutting all the branches to the ground except for the largest, fattest branch in the middle? I know the suckers will be a problem for a while. Also, is it safe to grow a small vegetable or herb garden between them? Is oleander flower and leaf mulch safe around the edible garden?
A. Yes, you have the right idea. Oleanders can make very nice small trees but the suckers at the base will be a problem for several years.
|Oleander pruned to a multi-trunked tree and in bloom.|
They can be made into a single trunk or a multi-trunked tree. Multi-trunk trees are easier to manage. Select 5 to 7 stems, or branches as you call them, coming from the base and going in different directions. Odd numbers of branches are more pleasing to the eye than an even number. Those are the stems you will keep. They should be large and vigorous.
|Oleander suckering from the base when pruned as a multi-trunked tree.|
Remove all other stems as close to the ground as possible. A reciprocating saw with a pruning blade is an easy way to remove them than a saw or loppers. Remove side branches from the stems up to a height that looks good to you. The trunks should be cleaned of side branches. Make sure you cut these side branches as close to the trunk as possible. Clean the trunks anywhere from 2 feet up to about 4 feet.
New stems will sucker from the base throughout the growing season for several years. This is because oleander wants to be a shrub. You are forcing it to be a tree so it will try to revert back to a shrub.
As soon as suckers emerge from the base, remove them by pulling rather than cutting. If you pull them when they are very new they are easy to remove. Removal by pulling causes fewer suckers in the future than cutting them.
Oleanders are poisonous but research from California demonstrated that leaves and stems can be composted and returned to the soil without problems for other plants including vegetables.