Repeat application of the oil (make a new batch each time) in a week, and continue each week until pests are gone. If it rains, you may have to treat more frequently–hort.uconn.edu advises rain will degrade neem oil; so, after a rainfall, when the foliage has dried, you will need to treat plants again.
【How-to】How to use neem oil on tomato plants
|
