Top Ten Tips to Recovering Your Garden After Flooding

Above: spiders in the trees in Sindh, Pakistan, after the catastrophic violent floods in 2010.

Both the UK and parts of the US (and several other parts of our planet) have been experiencing stormy weather in the last few weeks. How on earth do you recover your garden after a flood? Usually people, pets and houses come first. But for a gardener, the loss of plants can also be devastating. Follow our top ten tips to recover your garden after flooding if you’re in this situation and we hope we can help you restore your garden to its former glory over time. Weird and wonderful things can happen to your landscape after a flood.

Tropical Storm Debby created havoc in Florida, June 2012. Besides wind and flooding, many sink holes appeared. These examples are extreme, and usually lost plants can be replaced and gardening communities tend to be very generous with sharing plants and lending a hand.  Once you know everyone is safe, start helping your garden recover, and it may even become more vibrant post flood.

1. Don’t wait! Especially if your garden has been flooded with salt water. You need to wash down and rinse plants off immediately and water well within 48-72 hours. Rinse off any mud or salt spray covered foliage and remove any build-up of storm mud and detritus from the base of your plants. This rinsing process removes the likelihood of disease spreading through cuts and wounds on the leaves and stems of your garden plants.

 Remove Salt Spray from under leaves

Make sure you wash off both the tops and bottoms of the leaves as dirt or salt water on the undersides of the leaves is just as damaging as on the top surface of the leaf. Salt water especially needs to be removed immediately, since the longer it remains on the plants the greater the damage it will do. Once the plants have been rinsed they can begin the process of revival

2. Melons, eggplant, winter squash and other vegetables with hard rinds may be contaminated on the outside, and that contamination can be transferred to the edible flesh when cutting them open, so clean them thoroughly.

3. Water plants. Whilst it seems odd (and it may feel wrong to add more moisture to already soaked soil since saturated soils are detrimental to root and plant health) - You do need to remove mud and other pollutants.  The good from removing the mud and other pollutants out-weighs the potential damage of further saturating the soil.  Also, this process dilutes the concentration of pollutants, making them less harmful to plants and speeds the plant’s natural recovery from extreme weather.

4. Make a storm compost pile. When having to remove large amount of mud and debris, consider making a storm compost pile in an out of the way part of your garden.  Layer leaves, stems and debris with the mud brought in by storm waters, this material will eventually become compost, which can be used to add organic matter to your soil.  At least in this way something good comes from the damage.

Shugborough Hall, with flooded gardens frozen, Staffordshire, England.

5. In severe salt water damage, it is possible to use gypsum to help limit the damage. The idea is that gypsum interacts to replace sodium (salt as in seawater) with calcium. Initially this causes a rise in the overall salt content of your soil. Try to get an expert opinion before using this method.

6. Once you have cleaned the mud and salt off of your plants (as much as you can), you can see what’s actually broken. Also, giving plants a day or two (or more) to recover will help you in seeing where and if new growth is already emerging. If there is new growth appearing this should guide you to decide where to prune.

7. NOT APPLY FERTILIZER right after salt water flooding, as fertilizer is also composed of salts and can actually increase damage. You need to sit it out until plants begin to show strong growth, before applying fertilizer.  When you do apply fertilizer, as aways – make sure you read the directions.  You may be tempted to apply a stronger than recommended dose.  Don’t.  Fertilizer applied at a high rate can damage delicate root systems.

8. Deal with your largest trees and shrubs first, focus on downed trees and of course anything affecting personal safety. Where there is risk, consider bringing in professionals to remove the large damaged woody material.

9. After dealing with the major damage, move on to removing snapped branches, bent or damaged growth and broken leaves.  Stems can be pruned back to the next potential new shoot.  Look for new growth that might be emerging or buds.  Remember that a hard pruning after a storm can be an additional stress to plants already under pressure. So, when in doubt remove the bare minimum. Then come back in a week or two and see what else needs to be dealt with.

10. If your pots have been saturated with salt water, simply replace the soil entirely. If you left the soil, residual salts in the soil would really limit plant growth and health. The old soil can be composted. It will shed most of the salt in the composting process. If you have a special plant in a tub and replacing the soil isn't possible, flush lots of water through the soil to rinse out salt buildup.  Because containers drain out excess water, super saturation of soil is less of a problem than it can be in the landscape. Allow the soil to dry as you normally would before watering.

If your container was flooded with non-salt water, you may still want to replace the soil and start again.  However, you could also give your plants time to recover. Since salt buildup isn't an issue, you shouldn't need to flush water through the soil and you DO want to fertilize.

While storm damage is never pleasant it can often surface new areas in the garden, allowing for change as well as providing fertile compost for a renewal of beauty as the garden recovers. Try to look for the silver lining as you clean up, maybe a new view, richer soil, or a chance to take your garden in a new and exciting direction!

Storm induced flooding can also act to enrich a garden by bringing in new soil with high levels of organic matter. Similar to a river delta this can be extremely fertile soil, so as long as it is not so thick that it smothers the plants, most gardens will recover quickly after being flooded. For turf grass and ground cover plants, removing the majority of the soil that was washed in and relocating it is the first step. Once the tips of the plants are showing through, try to rinse the remainder of the soil below the leaf tops and let nature take over.