Basic Tips for Growing Herbs in Sub-Tropical South East Queensland
Position: Most herbs are hardy and will grow well throughout the garden, or in a separate garden of their own. Grow herbs amongst your vegetables, they make great companions and they can improve growth and flavour of vegetables and help repel pests.
Choose a spot close to the house for easy access, if you are planting herbs throughout the garden place the ones you will use the most, close to the house. The first step is to decide which herbs you would like to grow and how much room you will need. Make some notes on how they grow, how tall, how wide, do they like lots of sun or do they prefer shade.
Sun: Generally, herbs need full sun, but some will survive on as little as 2 hours of good sun (after 9am) a day. The herbs flavour and scent is stronger when they have adequate sun. Herbs with grey leaves like lavender and rosemary require more sun, whilst parsley, mints and lemon balm will take less.
Soil: Most herbs need good drainage and grow best in a light crumbly soil. Clay soils will need compost and manure dug through, building up the garden to ensure good drainage. Sandy soils also need compost and manure added to give nutrients and help retain moisture. Most herbs like a slightly alkaline soil you can add dolomite to increase pH.
Fertilise: Fertilise with a complete fertiliser or organic liquid fertiliser. You can also use mushroom compost, worm castings and homemade compost containing chook or cow poo.
Planting: When planting out your herbs, soak the roots/tube for a minute in a solution of seaweed, this will help to prevent transplant shock. Trim off any yellow or damaged leaves.
Water: When herbs are first planted water them in well. Water regularly for the first week or so. Once plants have settled in, rather than giving frequent light sprinkling, water deeply less often, this will encourage plant roots to grow deeper into the soil.
Mulch: Mulch (hay, straw, cane mulch) insulates the ground and reduces evaporation, reducing the amount of watering. Mulch also stops weeds from growing.
Pots & Baskets: Herbs grown in pots and baskets need a little more care than when planted in the ground. Make sure the container you use has enough drainage holes to prevent roots rotting. Use a good quality free draining potting mix. Organic liquid fertiliser can be applied every couple of weeks or you can use a slow release fertiliser. How much you need to water your pots of herbs will depend on many factors including how much sun, wind and the type of pot or container you use, some will dry out quicker than others (unglazed terracotta pots dry out very quickly.) Use your finger to check if the herbs need watering, stick your finger 5cm into the soil, if the soil is damp do not water, if the soil is dry give the herb a really good soaking, then let it dry before watering again. It is better to water really well every few days than to give a light sprinkle every day.
In short: Whilst most herbs grow well in full sun, it is advisable to keep the newly potted plants out of direct sunlight to settle in for a couple of days, before putting them in a sunny position. If planting into the ground, make sure it is a well-drained spot with adequate sunlight. Once planted, water in well.