|I have a year-old row of lavender in my full-sun yard. I have been having trouble keeping them from getting|
|Lavender is a woody perennial and the key to keeping them nice looking is cutting them back on a regular basis - at least twice a year, but more often if you can time it right. When you pinch out the tips of the stems the plant develops more stems and each of these stems has the potential to bloom. The first pruning should be in the spring, when new growth reaches about 3 inches in length. At that time, pinch out the very tip of each stem. After the plant blooms, the spent flowers should be cut off and the foliage should be cut back by an inch or two. When the new growth is about 3 inches long, you can pinch out the growing tips again. The more you pinch, the more new growth will develop and you won't see the bare woody stems in the center of the plant. If you prune a lavender back to bare wood, it usually will not produce new growth. While they are perennials, I usually remove mine after their third year and replace them with supple new plants (which I start from cuttings in mid-summer).
About the only other concern with lavender is that they need exceptionally well draining soil. If yours tends to hold water you might consider raising the bed by adding topsoil and planting each of your lavenders on a little mound of soil. This will ensure the soil drains well.
Hope this information is helpful.