Flood Affected Plants
Parts of Queensland amd New South Wales have experienced severe weather conditions, including strong winds, heavy rain, and flooding, due to cyclone conditions. Many gardens have been affected by these floods.
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.
It is important to avoid walking on waterlogged soils and lawns. Give everything time to dry out before doing more than cleaning and clearing.
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.
Floodwaters can contain pollutants so it is important to hose down or pressure wash all plants, lawns, hard surfaces and containers to remove mud and debris. Wear gloves and stout shoes and take care when moving items, watching out for dangerous debris and sharp items such as broken glass that may have washed in with the flood. If you haven’t had a tetanus shot in the past 10 years, consider get one if you are affected!
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.
What to look for during plant recovery
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.
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
Apply Seasol or Seasol GOLD as a foliar application every week 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.
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.
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 a fungal spray that is suitable to use on all plants. Check with your local hardware or garden centre for advice.
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 biocharcoal, 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.
Elevating pots helps with drainage for example raising pots on two bricks will allow water logged potting mix to drain (check that drainage holes are clear). If you are concerned that the flood waters were polluted it is wise to repot all potted plants and discard the old potting mix.
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.
Vegie gardens and fruit trees.
Avoid eating leafy vegetables, herbs, or any produce that may be contaminated. Remove and dispose of any food crops that have come into contact with floodwaters, including root crops that grow underground. New growth should be safe to eat within a month. If conditions have improved, consider removing and replanting the affected plants. If you’re uncertain about the safety of any crops or plants, it’s generally better to replace them.
For potted plants, remove the contaminated potting mix, wash the pot, and replace the soil with a high-quality potting mix, such as Seasol Advanced Potting Mix, before sowing new seeds or seedlings.
For vegies planted in garden soil, assess the condition of the soil, as many nutrients may have been washed away or contaminated. Replace soil where necessary, and mix in compost and organic matter, such as Seasol Super Compost.
Lawn Recovery
Avoid walking or parking on saturated lawns. Don’t allow children or animals to play or run on flood-affected lawns. Remove debris that may have washed into the property, ensuring that you wear gloves and boots. Pressure hose the lawn to remove silt and allow the lawn and soil to breathe.
Once the soil begins to dry out, hose away any residual mud and silt so the grass can start to photosynthesise. Nutrients and micro-organisms will have been leached from the soil so apply Seasol or Seasol Lawn & Turf Starter to help the soil and the lawn recover.
Do not apply any fertilisers, top dress or any additives until the lawn has dried out. If you find the soil and lawn repelling water (pooling on top of the lawn or running off the lawn) apply a soil wetter such as Seasol Super Soil Wetter & Conditioner to ensure water soaks in.
After the rain and while conditions remain warm, grasses will grow vigorously. Apply a Seasol for Lush Green Lawns to feed the growth and revitialise the soil. Resume mowing once growth returns first checking that the lawn mower hasn’t been damaged by flooding.
Treating damaged lawns
If parts of the lawn die, cover bare soil with mulch to protect the soil and prevent weeds while you prepare to re-turf or re-sow damaged areas.
If the soil has become compacted, it may need to be aerated with a metal fork or powered aerator to allow air to get back into the soil. After aerating, top-dress with Seasol Lawn Top Dress Mix to help revitalise the lawn allowing air, moisture and nutrients back in.
Flood waters do bring weeds into gardens and lawns so keep an eye out for germinating weeds. Remove them as quickly as possible by hand weeding or spot treating with a natural weed killer such as EarthCare Organic WeedKiller spray (but don’t allow the herbicide to touch the grass).
As the lawn regrows, mushrooms and odd fungus (such as stinkhorns) may appear in the lawn. These are a sign that life is returning to the soil. They will not be harmful to the lawn.
Future planning
Wildlife
Wildlife including birds may be sheltering in your garden or even trapped in debris and may appreciate fresh clean water and some bird food. or in the case of animals fruit or pellets. If you find an injured animal, call Wires on 1300 094 737 for advice, or if it is safe to do so, take it to the nearest vet.
For additional gardening tips on repairing the garden after storm damage, click here: Garden repairs & TLC after storm damage.
