A commonly held view amongst many home gardeners is that perennial flowering plants in general and herbal plants in particular, require relatively low maintenance, certainly as compared to annual bedding plants. This view is quite mistaken. Herbs such Rosemary or Lavender, Sage and Thyme actually need frequent and regular attention, as do many if not most herbaceous perennials. The principle task involved is pruning. To prevent such plants degenerating into an untidy sprawling mess, regular clipping is required. This is no truer than in the spring, when failure to prune on time often results in the plant not succeeding as a worthwhile garden specimen.

Pruning is important in order to neutralize the repressive properties exercised by leading buds on a branch or a stem, over those buds that are lower down on the stem. This phenomenon, known as apical dominance, allows a stem to push forward or upward. It is how a tree grows to a great extent. The result as far as sub-shrubs, herbs and perennials are concerned, is very often a top-heavy growth habit, meaning that the lower parts of the plant become bald, bare and unattractive over time. Therefore, pruning encourages lateral growth and as a consequence, the plant looks more compact and dense, as opposed to increasingly lank and leggy.

Why though is timing so important? What's wrong with the plant getting a bit long and thin, if it can be rejuvenated at some point by being cut down? The trouble is that many plants, especially herb species belonging to the Lamiaceae botanical family, (to which the majority belong) do not sprout new growth from old wood. That is why plants like Lavender, Artemisia, Melissa or Oregano look so great when young, and so disappointing within a year or so.

The solution then is to prune the plants back at the onset of spring, which is the principle growing season for most of these species. It is important to remember not to cut into woody parts of the plant, but rather only at herbaceous, growing points. It is best not to hold on to plants that have got "passed it". They should be removed and replaced. There are some exceptions though. Rosemary, which cannot be cut back successfully, develops an interestingly, gnarled, twisted bark in age. Old plants can be therefore be limbed up into mini trees about a meter high, (3 feet) making for an unusual vertical accent at such a height.

With regard to spring-flowering perennials, there is always the temptation to wait until the last flower has withered before pruning back the plants. This is often a
mistake as for many species, flowering constitutes the last spurt of growth before the relative dormancy of the summer. The consequence is exactly what ought to be avoided - namely the plant comes long, leggy and unbecoming. The best example of this is the ice plant (Lampranthus) from South Africa. The solution is to trim the plants after about 75% of the blooms have withered, thereby "giving-up" on the remaining 25%. This encourages lateral, vegetative growth that allows the plant to fill-out during the month or so before the onset of summer.