|I recently moved from PA to AZ. My house has several Oleander bushes trimmed to be treelike near the pool in the backyard. They are apx. 8-10 feet tall. Two weeks ago, two of the plants began to rapidly dry out....A local garden shop told me NOT to give them water which is strange to me. They are totally brittle now, leaves and branches. They and the healthy trees near them also seem to have big knots on the ends of there branches where flowers should be. Any ideas?
|Oleanders are susceptible to a bacterial gall or knot. Knots start out as small protuberances but grow into larger wart-like growths with rough surfaces. They can be about one-half to one inch in size. The bacteria enter through open wounds caused by pruning, frost damage or even natural openings in plant tissue. Splashing water or pruning tools can spread the disease from one plant to another. To treat, prune out all the infected parts and apply a solution of one part bleach to nine parts water to each cut. Wipe pruning tools with the bleach solution between cuts to help limit the spread. You can try trimming out the diseased portions, but new growth is often susceptible to re-infection. If large plants are severely infected, they may have to be completely removed. Note that all parts of oleander are poisonous. Wear protective clothing and do not burn the plant tissue as the poisonous fumes can be inhaled and respiratory difficulties created. Once established, oleanders can be hard to eradicate as they have tenacious root systems.