Flood Affected Plants

With at least 1/3rd of Australia’s population (northern Australia) experiencing severe weather including heavy rain and flooding over the last few weeks, it equates to many gardens that have been flood-affected.

As long as the water recedes within a couple of days most plants and trees will bounce back with little or no damage. If, however, the flooding lasts longer than a week, then survival will depend on the variety of plant. Most vegetable and herbaceous (non-woody stem) plants will not survive, whereas for larger trees and shrubs, it will depend on the variety and the damage done.

Follow our tips to help your plants and garden survive the effect of too much water.

Immediate help to the garden

Minimising damage is a priority once water levels recede. Digging a trench around valuable plants will help to encourage excess water to drain away, giving them a chance to breathe. Removal of mud and silt from foliage will also give plants the best chance to recover. Most of the mud and silt will fall off by itself, so hose off whatever is left.

Too much water can cause roots to suffocate and die due to a lack of oxygen. Toxins can also build up within the soil and kill plants. Plants may suffer as they are unable to photosynthesis and fungal disease may take hold.

Now is the time to keep a close eye on your garden and lawn and check for any damage. Plants will react differently and you may notice different changes with different plants.

What to look for during plant recovery

Damage from floodwaters may only be evident in a few months’ time. Symptoms from waterlogging include – yellowing of leaves and burnt foliage, dieback of branches and defoliation.

How plants cope with waterlogging will depend upon the length of time spent underwater. As favourable weather conditions return for plant growth, it may look a little different.

As plants start to shoot often there is reduced leaf size and premature leaf drop. Gradual decline is common and secondary infections can cause the ultimate death of plants.

Plant leaves could fall and dieback may happen, but don’t prune back any foliage or branches except for those that are physically damaged or dead.

Tips to help your plants recover

If roots have been exposed replace soil as soon as possible to reduce the amount of time exposed to the air. Seasol Garden Soil Mix is treated with Seasol GOLD, to aid the plant’s root systems to recover and regrow. This will help to support healthy strong growth above the ground. Use it by topping up to previous soil levels or incorporate into existing good soil, taking care not to damage existing root systems that may be struggling.

Apply Seasol as a foliar application every fortnight to strengthen cell walls and build up the plant’s resistance to diseases. Applications of 20mL concentrate per 9Lt of water (standard watering can) or use a spray system.

Once soils have dried out, apply Seasol to the soil via a watering can (30mL of concentrate per 9 litres of water) or hose-on spray as it will be beneficial for many plant varieties, including natives. It will help to rejuvenate plants by promoting strong root development and healthy growth. It will also aid soil recovery by stimulating beneficial soil micro-organisms.

Soil nutrients within the soil could also have been washed away by excessive water, so applying a light fertiliser such as Seasol Advanced will help replace leached nutrients and encourage new growth. It will also aid to revitalise soil health by applying liquid compost to it. Seasol Advanced hose-on is quick and easy to use, just attach it to your hose and off you go. It also has the additional benefits of Seasol.

Additional garden tips

How plants recover from too much water will depend on the variety and size of plant. Some plants will not survive, so remove these plants from the soil. Other plants will take time to heal and recover, they may go backwards before you see signs of improvement. Give your plants the time to do this. Once they show signs of improving, they will require the nutrients for regrowth. Apply a liquid fertiliser such as PowerFeed All Purpose including Natives as this will help to feed both the plants and the soil. Being a liquid it goes to work immediately to promote strong healthy growth. It also helps to improve the soil structure, improving nutrient uptake by plants.

Monitor your garden for pests and diseases that may be attached to weakened plants. If fungal diseases such as powdery mildew or rust appear on plant foliage, apply EarthCare Rose Black Spot & insect spray. It is an all in one treatment, by combining a systemic fungicide and insecticide. It is suitable for use on all flowering and ornamental plants.

As plant growth continues, they will take a lot of nutrients out of the soil. To give your soil an extra boost, applying applications of Seasol Biochar with Zeolite will help to bring it back to life. It combines a dynamic mix of bio charcoal, zeolite and paramagnetic rock to promote microbial activity, increasing soil fertility and nutrient uptake. It also helps to prevent soil nutrient leaching and assists with drainage.

If areas of the garden are vacant because plants have not survived, remove the urge to replace them with new plants straight away. Soil needs time to recover, including toxins to be removed, so give your soil at least a season to recover before planting. Apply homemade compost and organic manure and/or Seasol Super Compost during this time as it contains everything you need to take the guesswork out of revitalising soils and boosting plant growth. Safe for all plants in the garden including, annuals, bulbs, herbs, and vegies.

Pot plant tips

Remove pot plants to higher ground as soon as water starts to rise. If pots are too large and can’t be moved, then check plants as soon as water recedes again. Remove any barriers that may be stopping water from getting away and lift any potted plants that are sitting in a sauce of water and have been out in the weather off the ground, as the potting mix needs to dry out.

If plants have not survived then remove them and the potting mix as well. Clean the pot before using it again, remove any toxins left from the waterlogged potting mix. If plants have survived it is recommended to remove any potting mix soil and repot with fresh premium potting mix such as Seasol Advanced Potting Mix. It has everything in the bag to help your plants to recover and flourish including Seasol GOLD to aid plant establishment and recovery, promoting strong root development. As plants take off an additional application of Seasol and a liquid fertiliser such as PowerFeed All Purpose including Natives will continue to help plants to thrive.