Today is the first day of spring and this is the first planting guide of the season. The following is a list of vegetables you can plant in September in Sydney, a temperate zone. Just click on the link for the growing guide for each vegetable or herb:
- Beans – climbing and bush
- Cape Gooseberry
- Jerusalem Artichoke
- Mustard Greens
- Rockmelon in seed trays
- Snow Peas
- Sweet corn
Plant of the Month – The spectacular Azalea
Azaleas are slow growing, flowering shrubs in the Ericaceae (heath) family and in the genus rhododendron.
Azaleas fall into two types: deciduous Pentanthera and evergreen or Tsutsuji. Most evergreen varieties are native to Japan, with a few species each from China, Korea, and Taiwan. The deciduous species are native to eastern Asia, eastern Europe, and North America.
Flower shapes vary and some are perfumed so there is so many colours and sizes to choose from for the home garden.
They bloom in mass profusion and for many weeks in spring and also summer in the southern hemisphere. Few plants give such spectacular floral displays and their wide range of vivid colors, abundance of flowers, their ability to be grown in a wide range of soils types and climates makes the azalea one of the most popular flowering shrubs.
The evergreen varieties grown in home gardens are usually hybrids developed for disease resistance, flowering time, and cold or heat tolerance. This process of selection over hundreds of years has produced over 10,000 cultivars.
The Azalea will grow to a height of 60-180 cm and a spread of 30- 150 cm depending on the variety. They vary in form from compact dwarf to taller varieties and will take up to 3 years to grow to maturity.
The large variety of forms and colours make them useful for planting in beds, borders, containers and even hedges.
They are loved by pollinators and are attractive to bees and butterflies.
Azalea Flower Forms:
Azaleas can be distinguished by the shape and form of their flowers. Evergreen azaleas have six flower forms.
Consist of five or more petals with five to ten stamens and a single pistil. This is the most common form of the flower
Are like single flowers that have had some stamens transformed into petals.
Have have all their stamens transformed into petals
Azalea ‘hose-in-hose’ types of flowers
These can be single, semi double or double flowers. They consist of two flower forms that appear to be inserted into one another; the top flower can be made up of the petals and stamens and a lower flower consists of colored sepals that are fused at the base.
Single hose-in-hose flower:
Semi double hose-in-hose flower:
Appears to have 10 petals. They look like the single azalea but have one flower inside another made from coloured sepals that are fused at the base.
The centre is a modification of the stamens into petals with a single pistil.
Finally there are the
Double hose-in-hose flowers:
These combine the features of the double and the hose-in-hose forms. This flower takes on the aspect of a rose.
Hose-in-hose and double flower forms tend to hold their blossoms after flowering.
Site and Aspect:
To ensure best quality flowers and a long flowering period, choose a semi-shaded position, with morning sun. This is especially important if you live in an area that experiences extreme summer temperatures like Sydney. In Melbourne where the summers are milder, azaleas can tolerate being in full sun. The final choice will depend on the climatic conditions of your site.
Dappled sunlight is a safe option, with a position that receives morning light with afternoon shade and about six hours of sun spread across the day. If the location will have hot afternoon sun you will need to keep the moisture up to the plant. Extreme heat will burn the leaves and flowers.
Also consider the radiant heat that may affect the plants from walls that are north or west facing that can cause stress to your azalea and avoid planting close to them.
Avoid planting the azalea directly under trees where they will be forced to compete for available nutrients and moisture.
Additionally, it is essential that the site will allow water to drain away as azaleas will not tolerate wet feet. Do not plant in an area where water will pool in winter. Plant in raised beds if your soil is too heavy or to improve the drainage.
Azaleas require a light, free draining, acidic soil with a pH of around 5.5 that is rich in organic matter. Test your soil and amend as needed.
To amend an alkaline soil add compost, well rotted manures and leaf litter and dig through well. This process will need to be done about 6 weeks before planting.
The ideal time to plant your azalea is in the autumn or spring depending on the climate of your area. This will give the plant time to set its roots before the heat of summer.
Whatever the soil type, generously mix aged compost, ground pine bark or shredded decayed leaves with the existing soil, adding it at a ratio of one part organic matter to one part soil.
If planting more than one azalea, take into account the width of the variety you have chosen to allow enough space between plants. This could be anywhere from 60-180 cm depending on the variety.
Dig the area only to the depth of the root ball and make the hole 2 to 3 times wider than the root ball.
Firm the bottom of the planting hole with your hands to prevent the root ball from settling after planting.
As azaleas are shallow-rooted plants the planting depth is important. For sandy soils, the root ball should be placed into the hole so the top is about 2 cm above the surrounding soil surface.
For clay soils and poorly drained soils, place the top of the root ball 5 – 10 cm above the soil surface.
In effect, you will need to created a mound around the root ball, gradually sloping the soil to meet the original surface. This will aid settling and make sure that the roots will be in the top layer of soil where they can easily obtain oxygen, water and nutrients.
Then mulch with pine bark to a depth of 7-10 cm, keeping it away from the stem of the plant and reducing the chance of rotting of the bark. This layer will provide nutrients as it decomposes and will stop evaporation and conserve moisture. It also will protect the roots from summer heat.
Finally water thoroughly immediately after planting, watering in slowly so that the soil will absorb it without running off.
Do not fertilize at this time.
Azaleas can be grown in pots using a quality Azalea potting mix. Growing them in pots allows them to be moved when the climate changes to give them the conditions they prefer.
With azaleas over watering is a common cause of plant loss so taking care to allow the plant to dry between watering and take note of natural rainfall when assessing their needs.
Once week push back the mulch and carefully check the soil around the plant to a depth of 10 cm for dryness. In summer, regular watering will be required, particularly on hot days.
However, during the cool months of the year, a good soaking once a week should be enough.
Always water at the level of the soil and not over the canopy of the plant and its flowers or leaves as this promotes disease.
Water early in the day. Azaleas need 1 inch of water per week so if you do not get rainfall you will need to supplement with watering to keep your plant vigorously growing and flowering.
Using drip irrigation to water the plant to a depth of 30 cm can be a useful way of delivering water to the plant.
Always observe the leaves and flowers to give a you a cue as to the plants needs.
Potted azaleas will need more care during the hot months to ensure they do not dry out.
It is important to know that azaleas contain Grayanotoxin are toxic to dogs and cats and care should be taken with small children to ensure they do not eat any part of the plant.