Garden Recovery after Storms and Flooding
Learn how to help your garden recover from flooding, storms and salt damage.
Superstorm Sandy was only one of many devastating storms that affect the United States each year. The end result of these storms for a gardener is what to do when the storm passes? How does one recover from the damage of high winds, flooding and saltwater intrusion into the gardens we tend so closely each year? In reality, it is fairly simple; a gardener should break it into three categories:
- Wash down and rinse off
- Prune and remove the damage
- Clear away debris and recycle
First things first, tend to the damage to humans and pets before you start looking at your garden. Lost plants can be replaced and as you are probably well aware, gardeners tend to be very generous with sharing plants and elbow grease. Once you know everyone is safe, start helping your garden recover.
Wash down and rinse off:
The first thing to do after a storm, literally within a day or two of the storm - don’t wait, is rinse off any mud or salt spray covered foliage and remove any build of storm mud from the base of your plants. This rinsing process removes the likelihood of disease spreading through wounds on the leaves and stems of your garden plants. Remember to 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.
You may be hesitant to add more moisture to already soaked soil since saturated soils are detrimental to root and plant health. This is a valid concern, however, the good from removing the mud and other comtaminants out-weighs the potential damage of further saturating the soil. In addition, this process dilutes the concentration of contaminants, making them less harmful to plants and speeds the plant’s natural recovery from extreme weather.
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.
When dealing with salt water intrusion or flooding, it is even more essential to get things rinsed off quickly. The longer the area has been flooded or inundated, the more severe the long term consequences. 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 and you should check with your local cooperative extension service to get an expert opinion before using this method.
Prune and Remove the Damage:
Once you have cleaned the mud and salt off of your plants where possible, it becomes easier to see what is truly broken and what can be saved. Also, giving plants a day or two (or more) to recover will aid you in seeing where new growth is already emerging. The presence of new growth will help you decide where to prune.
The largest trees and shrubs usually need to be dealt with first, concentrate on items such as downed trees and anything which directly affects your personal safety. Where personal safety is at risk, consider bringing in professionals to remove the large damaged woody material.
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.
Clear away any build-up of mud or debris that is clinging to the trunk or bases of plants, this will help reduce the risk of secondary infections from high mud levels and dead plant materials. All of this storm residue can make good compost if you collect it and recycle it. However, if residue is left on or leaning against plants, it will usually begin to rot and in doing so will cause the plants to rot as well.
Clean away debris and recycle:
Storm water is NOT drinkable. In many cases it carries industrial or sewage waste. You should always be careful not only to avoid drinking storm water, but also avoid breathing the dust that arises from it and be very careful of any scratches or wounds you get while working in flood devastation. Check with your doctor to determine if you tetanus vaccination is up-to-date and whether you should get a booster. The bacterial levels are usually very high after a flood, so keep some antibiotic lotions or creams around to treat any minor cuts or scrapes. While the bacteria can be very high initially, this is part of what makes the soil and plant materials after flooding such great compost. Storm debris breaks down quickly and can be applied to the yard once the composting process is complete.
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 low growing 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.
Container Garden Recovery
In most cases, the same three steps apply to containers as they do to your landscape - rinse off mud and toxins, trim back broken or damaged stems and foliage and compost debris. However, containers have an advantage over landscapes, they are contained and thus easier to deal with.
If container gardens 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 prized plant in a container 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. DO NOT APPLY FERTILIZER right after salt water flooding, as fertilizer is also composed of salts and can actually increase damage. Wait until plants begin growing strongly, before applying fertilizer. When you do apply fertilizer, follow package directions. You may be tempted to apply a stronger than recommended dose. Resist that temptation. Fertilizer applied at a high rate can damage delicate root systems.
If your container was flooded with non-salt water, you may still want to replace the soil and start over. 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. Allow the soil to dry as you normally would. When you water use a water soluble fertilizer, following the package instructions. You may be tempted to use a higher than recommended rate - resist this temptation. The roots of your plants are likely to be a bit delicate and too much fertilizer could be detrimental. Have patience and fertilize as recommended. We recommend a water soluble fertilizer rather than a controlled release fertilizer in these cases, because water soluble fertilizer can be more quickly utilized by the plants. After using water-soluble fertilizer several times base fertilizer levels in your soil will be fine and you can feel free to switch over to a controlled release fertilizer, if you wish. Do rinse mud off of foliage and remove broken and damaged foliage and stems, unless this means removing all of the foliage. If damaged foliage is still green, you may want leave it to gather energy until new foliage emerges.
Additional information on flood and storm recovery:
Flood Damage to Landscape Trees. http://gardening.about.com/od/treesshrubs/a/FloodTrees.htm
Storm Wise Florida Landscapes. http://www.sfwmd.gov/portal/page/portal/xrepository/sfwmd_repository_pdf/bts_stormwise_landscapes.pdf