Thursday, 20 October 2011
Flood Response in the Home Garden
On Saturday, 17 September I received a heartfelt cry for help from a former student.
Karen wrote, "Hi Judy,
"I've taken several of your classes at Rutgers. I was wondering if you might have any advice for vegetable gardens after the flood from Hurricane Irene. I have contacted the Union County Extension Office, and they did not have any suggestions. My neighbors are all trashing their fruit and vegetable gardens, including peaches and berries.
"My property was under water for one day. Down the street a sewage pump was destroyed and spewed its contents into the flood water. A block away a home-heating oil tank ruptured, and its contents went into the water as well. My house is finally under control, and I am ready to start cleaning up the garden. The soil does not seem to be water-logged any longer, but the garden smells bad where there is still mulch. Miraculously, all the plants look very happy, except for the cucumbers, which died completely.
"My primary concern is for the state of my soil. I think the sewage in the water may not be a problem, since I always add manure to my gardens anyway (my garden is organic). However, I am worried about the heating oil, as I know it is toxic. I intend to rip out all my vegetables and annual herbs, cut back the perennials so I know what is new growth. I will see if my town's Department of Public Works will take the mulch (salt hay and cedar) off my hands, as I don't think it would be safe to compost it. I think it might dissipate with time, but I do not know if it will be wise to plant again soon. I have decided against a fall crop, but do you think the soil will be safe for vegetables next spring? Is there anything I can do to make sure my soil is safe for vegetables? My compost pile was under water too. Should I keep the contents?
"I would be very grateful for your thoughts. I know this subject is not within the usual literature, and I understand that what I am asking for is an unofficial opinion based on your experience and common sense."
Karen gardens in a city neighborhood of modest properties. Her techniques exemplify cottage gardening.
She mingles perennials with vegetables, herbs, and fruits in lush profusion and attractive display.
Her attention to creating healthy soil conditions allows the intensive cultivation of her property.
Yikes! What a problem. I decided to offer suggestions for these issues one at a time.
Issue: My property was under water for one day. Down the street a sewage pump was destroyed and spewed its contents into the flood water. A block away a home-heating oil tank ruptured, and its contents went into the water as well.
Response: Were you (so to speak) upstream from the sewerage or did it come onto your property? Ditto the oil - is there a petrochemical smell to the soil when you dig in it?
Issue: My primary concern is for the state of my soil. I think the sewage in the water may not be a problem, since I always add manure to my gardens anyway (my garden is organic).
Response: Sewerage is a different, more toxic substance than manure. It can contain household cleansers, laundry detergents, and other materials even less welcome as contaminants in the garden.
Issue: However, I am worried about the heating oil, as I know it is toxic.I will see if my town’s DPW will take the mulch (salt hay and cedar) off my hands, as I don't think it would be safe to compost it.
Update: On further inquiry Karen later found out that the exposure to heating oil was probably minimal, since the oil tank was in somebody's basement. The heating oil, therefore, was contained within the house to a great extent.
Response: Make a separate compost heap. These materials are all "browns" / carbonaceous material. Add "greens" / nitrogenous material such as dried blood. Stir all together, not separate layers. You want the heap to run hot. Use the compost for non-food crops. If - eventually - you find earthworms in it I would use it but again, for non-food crops.
Issue: I think it might dissipate with time, but I do not know if it will be wise to plant again soon. I have decided against a fall crop, but do you think the soil will be safe for vegetables next spring? Is there anything I can do to make sure my soil is safe for vegetables?
Response: You might find someone more knowledgeable about this situation if you call someone in the soil sciences department at Rutgers University. Meanwhile here are my suggestions. Plant winter rye as soon as possible. Till under in the Spring and plant another cover crop, such as buckwheat or alsike clover. Till in. You want to add organic matter to get the microorganisms really working in the soil. Plant a late season vegetable garden in 2012 but avoid root crops until 2013. This is probably a somewhat extreme reaction but better safe than sorry.
Issue: My compost pile was under water too. Should I keep the contents?
Response: If your compost heap was just under water but was not contaminated with sewerage and heating oil I don't see why not keep it. If you want to play it extra safe, use the compost for non-food crops. Autumn is coming, so you'll soon have lots of leaves to start a new heap. Chopped small (run over with lawn mower, for example) and add some dried blood or cottonseed meal or other nitrogen source and the leaves will quickly decompose.
And this is pretty much what Karen did.
Karen wrote when she sent me this picture, "Turning organic matter into the soil
(untreated grass clippings and salt hay that was half broken down)"
Next, she raked the soil to level it and then broadcast winter rye seeds.
I found myself continuing to think about this situation. On 26 September I sent Karen some additional information.
"I'm glad to hear that you're moving ahead with the restoration of your garden. Even if you won't be harvesting vegetables this fall I know how energizing it must feel to be doing something!
"I was thinking - even though it won't be the same as your mixed, cottage garden style what if you plant some containers. Many nurseries have a "pot dump" where people can dispose of plastic pots and nursery containers. They also often let people scrounge. I'm sure that if you explain the situation they'd be willing to allow you to get a few of the large shrub / tree containers, the ones with 2 handles, about half whiskey barrel size.
"You'd have to purchase soil / compost. This close to the Delaware River I have friends who have a truckload of leaf mold and / or mushroom compost delivered each Spring. There must be a source from whom you can purchase. The containers are certainly deep enough for beets and carrots. It may be somewhat late for this fall but it would certainly be possible to set up now for early planting next Spring."
Karen did dig her perennial herbs and wonderful strawberry plants. Cut back the herbs
and cleaned most of the soil from their roots before repotting.
Perennial herbs and strawberries were potted in clean soil, with pots
buried for the winter. Mulch to be added when it gets cold.
Update: Karen sent me an update on Tuesday 20 October.
Dear Judy,
I just received this response from a soil scientist at North Carolina State University. I thought you might like to know that he followed your line of thinking exactly. He added a really helpful suggestion to monitor the cover crops for potential troubles and to use this a gauge for future planting, which I intend to do next fall.
At this point the winter rye is very lush and beautiful, and I feel like I am living in a prairie. It will be a lovely scene to look out on during the winter months.
Thanks again for your generosity and kind support,
Karen
Subject: Re: Flood Response In the Home Garden
"I've been thinking about your questions quite a bit. Whenever soil flooding occurs, I think it's important to have an idea of what potential sources of contamination you are near that may enter the water and be moved to your soil. For example, is the land near a waste treatment facility or pesticide storage area that was flooded and may move contaminants to you. If those types of sources are not in close proximity, contamination levels will likely not be too high.
"I think potential contaminants, like pesticides, if they have moved into the soil, will not last long. Natural breakdown and the low concentration of them in the floodwater is not likely to make them a long term problem. You will know after your cover crop season. If you see problems with seedling establishment, you may consider a spring cover next season and wait until fall to plant. If you are very worried about contamination, I believe the local extension office may be able to connect you with a laboratory that could sample for specific contaminants, but I know that these tests can be very expensive and may not give you much information about how to correct the contamination.
"My recommendation is to monitor the cover crop and see if there is any unusual growth there. If that goes well, you should be fine for next spring."
.
Some closing thoughts from Karen: "Although the water raged down my street, it only flowed gently through people's back yards and filled my yard for less than a day. The high-water marks on my buildings indicated that the garden was under a foot of water, but it is also possible that even the tops of the plants could have blown down in the wind to come in contact with the water at some point. So I am trying to be as cautious as possible. Now, with all the cleaning finished and the winter rye in place, I am at peace with the hurricane."
This lush garden with eggplant and strawberries, Swiss chard and kale exists, now, only as a memory.
The vegetables would have gone to the compost heap in any event. Winter is a time for envisioning
the garden that will sprout, renewed, in Spring. All will be well, I am sure, with garden and gardener.
Update: 28 October 2011
Something positive is coming from the anxiety and distress with which Karen had to deal,
the flooding of her home and garden. She just gave me the following encouraging update.
"The winter rye is lush and green, although the first patch is developing some yellow spots. I expect to be planting more cover crops next year. Now that the house and garden are both taken care of, we have joined a citizens group and are spending a lot of time working toward goals for township response to flooding. All the towns along the Rahway River are joining forces so I am hopeful that there will be progress this time. It is complicated and not fun at all."
Complicated, for sure. Not fun, definitely. But at the same time it is a positive response,
the coming together of people seriously affected by Hurricane Irene with the laudable goal
of reducing future problems. Storms cannot be eliminated but the damage can be alleviated.