This lobelia cardinalis can't get enough of the recent wet weather
To most gardeners the name lobelia conjures up the pretty and delicate plant bought at the garden centre for your hanging basket or for edging a flower border. These annuals are easy to grow and can be raised from seed. There are perennial varieties that can be grown beside water or in a mixed herbaceous border. There are aquatic species for a pond. Lobelias like a fertile, moist soil in full sun or partial shade.
To improve the flowering performance of annuals give them a liquid fertiliser every two weeks in spring and early summer. Grow aquatics in baskets of acid soil at the margin of the pool.
Lobelia cardinalis is a short-lived moisture-loving plant with green leaves and a display of bright-red flowers from July to August. Many other colourful forms have been bred from this plant. Lobelia cardinalis ‘Queen Victoria’ with its dark, almost black, foliage and red flowers, is one of the true stars.
Lobelia tupa is a giant of a plant, very tropical in appearance, growing in height up to six feet tall and with a spread of four feet. This lovely plant has pale green leaves and scarlet red flowers. The flowers are produced on spires up to 18 inches long from mid-summer to mid- autumn.
The plant is a native of Chile and will not tolerate temperatures below -10˚C. It likes a moist soil enriched with well-rotted manure or compost. The plant can be propagated from seeds sown from February to March; do not cover the seeds, they need light to germinate. Lobelias are best planted in spring.
Flowering bulb of the week
Dierama (Angle’s Fishing Rod or Wand flower) is a plant to admire at this time of the year. The common name Angle’s fishing rod comes from the plants slender, graceful curving pendulous stems. The plant is evergreen producing clumps of long narrow grass like leaves up to three feet tall. At this time of the year it produces elegant arching wiry stems up to six feet tall, bearing funnel shaped pinkish purple flowers. The tall stems move like a fishing rod in the wind. The plant is hardy in all but the coldest districts, looking super when grown in gaps in the paving around a garden pool, in a situation where their elegant is reflected in the water. Dierama should be planted among low growing plants to accentuate the plants arching stature.
Plant the bulbs 3-4 inches deep in the autumn or spring in a humus rich well drained soil, in a sheltered position in full sun. Dierama does not like being disturbed, divisions and young plants are slow to establish and may take 3-4 years before they flower, but once established they are trouble free and well worth the patience needed to see them flower. Propagate by division in spring or by seed, sown in a cold frame as soon as it is ripe. If grown in a gravel area they will self seed themselves. Most of the dieramas come from South Africa and produce flowers that are red, pink or purple.
Onions are coming to the end of their growing season. When the leaves bend over, growth is finished. Lift the onions about two weeks later and dry them off in a sunny place. Hang the bulbs in a dry, cool place to store them over winter. ‘Red Baron’ produces red-skinned onions that are attractive in salads.
Jobs for the week
Buy spring-flowering bulbs, the quality and variety of bulbs will be much better at this time of the year than later, when the best bulbs will be gone.
Keep up the battle with weeds by pulling them before they go to seed.
In the glasshouse continue to water plants growing in pots or grow-bags regularly. Remove side shoots on tomatoes and cucumbers. Water and feed hippeastrum bulbs regularly.
Plant out savoy cabbage and other winter varieties including cauliflower.
Remove flowers from herbs to encourage new growth.