Why is my lavender spindly and woody? Lavender can last 10-15 years but they will become progressively more woody as the plant matures. If you don’t prune your lavender every year, the rate at which the Lavenders becomes woody will increase. Pruning in the right way at the right time will slow down the rate at which lavender becomes woody, will improve blooms and extends its life. If it’s time to replace your lavender there are a couple of things to consider, checking that the new plant is isn’t