A number of vegetables need warmer soil conditions for their seeds to be able to germinate successfully. This means that seeds of these vegetables should be planted out at this time of the year.
Seeds needing these conditions for germination include; carrots, cucumbers, parsnip, silver beet and dwarf beans. Carrots planted now will be available for harvesting between April and May. Carrot seeds are best sown directly in rows at a depth about three times the diameter of the seed. As carrot seeds are rather fine, mixing them with sand will help to obtain a more even distribution in the soil.
While they are a hardy vegetable, carrots grow better when the ground has not been over fertilised as this can cause the roots of the plants to split.
Cucumbers are best raised from seed that has been planted directly into the garden bed. Some varieties of cucumbers like to climb over a framework while other varieties grow as bushes.
Growing plants over a trellis or framework will save space in the vegetable garden. Harvesting should be possible from April. Humid weather can lead to fungal diseases, particularly powdery mildew. This will become apparent as a fine white powdery covering on the leaves. Equal quantities of water and fat-free milk can be mixed together to form a spray, or commercially available products are also available.
Parsnips are more of an old-fashioned vegetable that is valuable for inclusion in winter stews, although they are also most suitable for roasting.
Their seeds are similar to carrots and, as for carrots, mixing the seed with sand will help achieve an even distribution. Seeds should be sown direct into the garden bed. They will be available for harvesting in June.
Silver beet seeds should be sown directly into garden beds. The edible, dark-green, glossy leaves, with wide white or cream stalks are produced over a long period, starting in March. Both leaves and stalks can be eaten. Silver beet is reasonably heat and frost tolerant and grows well in most soils. However, soil that has had compost or well-rotted manure added will result in plants with prolific growth. As with most other vegetables, regular harvesting will prolong the productive life of the plants as well as encouraging new leaves to form.
Dwarf (French) beans are easy to grow. The individual seeds, which are reasonably large, should be sown at a depth approximately three times the diameter of the seeds. Bean seeds are traditionally sown in rows, although, if the garden area allows it, they can be broadcast (spread) over the garden bed. They can then be covered with soil, potting mix or compost. The soil should then be firmed down with the back of a spade.
Once they emerge from the soil, the young plants should be kept watered. Young beans should be picked regularly in order to encourage flowers and continuous cropping. Protect the very young beans from slugs and snails.
Crepe myrtles are also displaying their bright colours, with the plants almost covered in large flower heads of white, purples, pinks and reds. Examples can be seen in many streets and gardens at this time of the year.
In addition to their colourful summer displays, crepe myrtles display good autumn leaf colours and the bark on their trunks have most attractive mottled patterning in winter, when the plants are bare of leaves.
Crepe myrtles, lagerstroemia indica, are native to eastern Asia and are hardy in most in most areas. Older varieties reach between six and eight metres in height, although many are pruned to shrub size. These varieties are often subject to attack by powdery mildew. This fungal disease causes the leaves to be covered in a white coating and become disfigured. It can also affect the blooms.
However, new varieties in the Indian Summer range have been developed to be resistant to this problem. Indian Summer crepe myrtles have a good cold tolerance, particularly if planted in a warm, sheltered position. A wider range of growth patterns to suit different preferences is also available.
Indian Summer crepe myrtles are a cross between lagerstroemia indica and lagerstroemia fauriei. Each cultivar is named after an American Indian tribe.
Varieties of Indian Summer crepe myrtles that grow about three metres include; Acoma (white flowers and a weeping habit), Tonto (rich pink flowers, and Zuni (mauve flowers).
Taller growing varieties are; Sioux (carmine pink flowers), Yuma (mauve flowers), Tuscarora (rose red flowers) and Natchez (white flowers with spectacular marking on the trunk).
Lagerstroemia indica, ‘New Orleans’ is available in shrub-form but can also be grown as a standard. It looks great in a large pot and is perfect for a courtyard garden.