The onion-like smell of the stems and leaves indicates that they are onion weed.

In order to get rid of onion weed, it is necessary to prevent the bulb from storing food.

In lawns and park the presence of onion weed is usually a sign that the grass needs to be growing more vigorously. Healthy lawn grass will out-compete onion weed in a reasonably short time. Mowing the lawn will remove the leaves, which will cause the bulblets under the ground to eventually starve. However, it is important to remove the flowers before they form seeds as these will only produce new plants.

Onion weed in garden beds is more difficult to eradicate. Removal of the flower head as soon as they appear will offer some control. However, because onion weed is a perennial weed, it stores nutrients and carbohydrates in its bulbs to generate growth the next season, in the same way as spring bulbs such as daffodils.

If attempts are made to pull the plant out the parent bulbs release tiny bulbs (bulbils) from the base of the main bulb, resulting in the growth of more plants. Digging out the plants will have similar results, unless care is taken to remove the bulbs and the surrounding soil that may contain smaller bulbs.

Cutting off the foliage, including flower stems, at ground level will prevent the plants from making carbohydrates in their leaves, as well as reducing the amount of seeds that are produced. Covering the cut stems with mulch will reduce the amount of sunlight that can get to the plant. It may be necessary to repeat the process several times, but the plant will become weaker and, over time, control of the weed will be achieved.

The leaves of plants may also be coated with a glysophate-based product. However, because of the thin nature of the stems and leaves, this can be quite difficult and time-consuming. Great care must be taken to apply the poison only to the leaves of the weed, as any other leaves receive it will also die.

Salvias belong to a group of plants that is most versatile and beneficial in different ways in the home garden setting.

Many gardeners will be familiar with one of the more well-known members of the Salvia family, although they might not recognise it because of its name.

Sage, a favourite herb for use in stuffings and sauces, stews and soups, is actually a variety of salvia. Salvias belong to the mint family of plants and many have strongly aromatic foliage, a feature that makes them useful in the home garden. In fact, sage is just one of more than 900 members of the salvia genus of plants that range from annuals through to herbaceous and shrubby perennials.

New varieties become available each year, so the salvia enthusiast is always able to add to their collection of attractive and interesting plants.

Apart from their aromatic foliage, which is often also most attractive and can vary from soft furry leaves through to shiny leaves that might be grey, silver of one of many shades of green, one of the main features of many varieties of salvias is the colour of their flowers. These can range from white through most shades of blue and deep, intense purple to hot pinks, cerise, reds and even yellows.

The actual colourful petals often have an outer layer of a papery bract that is also attractively coloured, sometimes in a contrasting shade. The bracts can remain on plants long after the actual flowers have faded.

Different species of salvia bloom in different seasons, with some flowering over several seasons. This feature means that the gardener can choose varieties that will provide year-round colour in the garden.

Salvias have many differing growing requirements, depending on the variety. They are available in a variety of growth styles and habits, ranging in height from annuals and some perennials that reach to about 30cm, through to large shrub varieties that can reach between two and three metres.

Most salvias prefer a temperate climate, although some are tolerant of more humid conditions.

Because of the nature of their growth, salvias benefit from regular trimming. This will maintain a compact shape while encouraging vigorous, new growth. Cutting back to just below the old flowering stems is a good guide. A regular display of flowers will result, according to the variety being grown.

Plants should be cut back hard towards the base of the plant when a more vigorous pruning is necessary, preventing the plant from becoming old and woody. Cuts should be made just above any new shoots that are visible in the lower part of the plant. In areas where frosts are prevalent it is preferable to defer hard pruning until after the frosts have finished.

Many camellia japonica plants will be getting close to flowering, with some of the earlier varieties already displaying their blooms. If the buds have been produced in large groups, removing one or two of the buds will allow the remaining buds to develop result in better flowering.