Lobelias are compact, generally blue coloured annuals, valued by gardeners for their long lasting, heavenly displays in spring and summer.
Lobelias are named after Matthaeus Lobelius the 16th century botanist known for his system of plant classification and believed to be the first botanist to value the distinction between monocotyledons and dicotyledons.
There are some 400 species of Lobelia belonging to the bell flower family Campanulaceae which contains trailing, upright, mounding, annual, perennial and shrub types.The trailing varieties such as Lobelia 'Sapphire' with stark blue flowers and tiny white eyes in the centre are very appealing for hanging baskets while the upright perennials are the brightest of all and thrive in moist, shady places in the garden.
The stand out amongst the perennials would be the North American native, Lobelia cardinalis, with its dramatic vivid red flower spikes and bronze foliage. In its natural environment it's found growing in marshes and alongside water ways.
There are 20 Lobelia species found in Australia including Lobelia anceps a small perennial herb with a predominately trailing habit and small mauve/blue flowers; Lobelia pratioides a small prostrate form with pale blue or lilac flowers in summer; Lobelia erinus 'Cambridge Blue' a fast growing compact plant with light blue flowers for baskets and pots and Lobelia gracilis with soft blue flowers that look pretty beneath roses.
In the open garden Lobelias like a light, sandy loam and protection from frosts and strong winds and enough space to sprawl out especially when mass planted.
They are easily grown from seed, cuttings or divisions of the old plant, as seedlings generally do not come true to colour. Selected plants are best propagated vegetatively.
After the summer blooms have faded cut plants back by half to two-thirds, keep the water up, and this should regenerate new growth to produce another flush of blooms in autumn. Pinch back plants at any time to maintain bushier growth. An application of a slow release fertilizer should sustain them throughout the growing season.
A lovely ornamental erect or weeping small tree suitable for a damp area in the garden is Viminaria juncea commonly known as the native broom. With bright green needle-like leaves and sprays of yellow pea-shaped flowers with an orange corolla, often with red markings, it blooms from late spring through summer.
Viminaria juncea is a unique species being the only one in the genus Viminaria endemic to Australia and found occurring in all states except the Northern Territory. Swampy depressions in heathlands are its natural habitat. It has an interesting survival mechanism in that it is able to regenerate after a fire from seed stored in the soil.
The botanical name is derived from the Latin vimineus meaning switch and juncus meaning rush-like.
A fast growing, small tree it can reach up to 4m high with a spread of about 2m and can withstand some water-logging as well as periods of drought in summer. Plant in a sheltered, moist to well drained position in sun to part shade.
MORE GARDEN TIPS
February 20: The Westbury Garden Club holds its Summer Flower Show at the Westbury Town Hall, Lyall Street, from 1pm to 4pm. Enrty $2, afternoon tea $5.
Daily: Emu Valley Rhododendron Garden, Burnie from 9am to 4pm. Closed Christmas Day and Good Friday. World acclaimed 11ha woodland garden features 24,000 rhododendrons and companion plants in a magnificent setting. Tea room 9.30am to 4pm.