WATERWISE GARDENING FOR A BRISBANE SUMMER
Whether they be in pots or a garden bed, water and heat stress leads to sick and non-productive plants prone to disease and pest attack and – at worst – plants dying. Horticulturalist Claire Bickle comes to the rescue with tips to save you water, time and money.
ORGANIC MATTER MEANS WATER SAVINGS AND HEALTHIER PLANTS
Garden beds that have good quantities of organic matter will hold moisture more effectively and not dry out anywhere near as quickly as soils that are lacking.
When preparing a new garden or tending established ones, add organic matter such as regular compost, animal manures, worm castings, composted leaf litter or mushroom compost. Dig it in with the existing soil, or even apply it as a thick layer on top which should then be covered with some mulch on top.
THE BENEFITS OF MULCHING
Mulching just 6cm thick can reduce moisture evaporation from the soil by up to 60-70%. Mulching has many other benefits such as:
- protecting soils from severe temperature fluctuations
- preventing erosion from wind and rain
- stopping excessive weed growth
- creating a micro ecosystem for beneficial fungi and insects to dwell in
- improving soil structure and release nutrients as they decompose (lucerne and sugarcane mulches)
- allowing plant roots to more effectively use the top few centimetres of the soil where there can be abundant nutrients.
Keep in mind you can mulch the tops of pots, too. Choose anything from finely chopped sugarcane to fancy glass pebbles.
RE-WETTING AGENTS AND WATER CRYSTALS
The use of a soil re-wetting agent can reduce your watering by up to 50%, making it very valuable throughout the dry and hot months of the year.
When soil, lawn, potting mix and garden beds dry out, the surface tension causes a waxy film to form on and around the particles. The area becoming hydrophobic (i.e. water repelling) and no matter how much you water, it keeps running straight off.
Using re-wetting agents will break down that waxy film and help prevent it from reoccurring for a time.
Water crystals are different; they basically improve the soil or potting mixes ability to hold water beneath. They are generally mixed through the soil at the time of planting or added to potting mix. Once the water crystals become wet they will absorb the water and swell up to form a clear water holding jelly like substance which will water plants over a period of time.
The use of liquid seaweed in gardens and pots is good news all round. It will help plants to be more drought tolerant, more tolerant of temperature fluctuations, strengthen plant cell walls and improve the water and nutrient uptake capacity of your plants.
POTTING MIX BUYING TIPS
Always spend that little bit extra for a good quality potting mix that has the Australian Standards ticks on the packaging. These potting mixes have much better water holding capacity than cheap no-name mixes.
Good quality potting mixes will also have a set amount of slow release fertiliser in them, re-wetting agents and water crystals.
WATERING ON HOLIDAY
For indoor plants, sit them in a bath tub with a few inches of water, or use plastic tidy tubs if you don’t have a bath.
If no one can water your outdoor plants while you are away, water the garden thoroughly and apply some wetting agent and liquid seaweed, then mulch thickly. This should hopefully see your garden through. For tender plants, maybe even erect some shade cloth to provide more protection.
Finally, choose wisely when selecting plants. Think about or research what type of plants are going to fit in with your level of care and time available.
Brisbane City Council provides a helpful guide to native plant species, many of them hardy and drought-tolerant.