What do hurricanes mean for your plants? Too much water
Saturday, September 22, 2018
As hurricane Florence made its landfall last week, it left the Greenville area relatively spared, thankfully. But what did this hurricane mean for our garden or landscape plants? Landscape and garden plants can suffer from “wet feet” due to all the water we received, even if you are not in a flood-prone area. “Wet feet” is simply a term to describe plant roots that are suffering in waterlogged soils.
Why do plants show signs of stress or even die in waterlogged soils? First of all, plants need carbon dioxide from the air in order to make their food through photosynthesis. However, plant cells, including roots, need oxygen in order to respire to use food obtained from photosynthesis for energy. In short, plant root cells need oxygen to live. Typically, roots can easily get needed oxygen in the air-filled pore spaces between soil particles. But when soils are waterlogged, those soil pore spaces are filled by water, causing plants to drown and roots to die.
Some trees such as sycamore, cypress and swamp white oak can tolerate and even thrive in waterlogged soils. Other common plants, including boxwood, hydrangea and juniper, will suffer and die off if they are given an excess of water. Plants suffering from “wet feet” may die outright or experience twig dieback later depending on the specific plant, water and soil situation. Twig dieback usually occurs later in the season because as soils dry out, the damaged root system can’t keep up with the water needs of the plant.
There is nothing that can actively be done when plants are in standing water, which is why it is important to be proactive and ensure the right plant is in the right site. However, if plants were in standing water for a period of time that has now receded, provide the plants with proper growing conditions such as such as proper watering, fertilizing, pruning and sunlight.
Within the next few days, if plants appear to have died from wet feet (leaves fall off, wilting), do not be too quick to remove them. Wilted leaves may recover in a few weeks if the plants can tolerate the saturated soils or if the soils drain quickly. Plants that drop their leaves can mean a variety of things when it comes to the plant’s health. The obvious thought is that the plant may have died and not recovered. Another possibility is that the abscission (dropping) of the leaves will cause the plant to go into dormancy, but if there is enough stored energy in the plant, it will releaf in the spring. A third possibility is that a plant may drop its leaves but attempt to push out a new flush of growth this year. This is more typical when a plant is damaged by a late frost and has time in the spring and summer to leaf out a second time, but it is a possibility for plants flooded by this hurricane.
If plants show obvious stem rot at the soil line or doesn’t leaf out in the spring, the plant is dead and will not come back, so it’s time for a replacement. We cannot always predict let alone plan for flooding, but we can always learn from experience. Keep note of which plants tolerated these excessively saturated soils and which died off. This helps to ensure success of replanting by replacing plants that can tolerate the growing conditions of the site.
If you have any questions regarding the health of your plants after the hurricane or need any gardening information, the Pitt County Master Gardeners would be happy to help. They can be reached from 10 a.m.-2 p.m. Mondays, Tuesdays and Thursdays at the Pitt County Arboretum, on the phone at 902-1705 or email firstname.lastname@example.org. Thanks for reading!
Eric Derstine is the horticulture agent with the North Carolina Cooperative Extension Service-Pitt County. Contact him at email@example.com.