We gardeners can be a cranky lot when the weather doesn’t sync up with our plans. I interviewed Dr. Steven McNulty, Director of the USDA’s South East Regional Climate Hub (SEARCH), to find out what gardeners can expect in 2016. Dr. McNulty explained how weather off the South American coast is linked to what happens in my garden in Durham. You can read more about this interview in the January / February issue of the Triangle Gardener magazine.
Key Points
- El Nino events are driven by warm water off the South American coast near the equator and they can impact the weather across the southeastern United States.
- Intense rainfall (more than 2” in a 24-hour period) can flow over the land and not be absorbed into the soil. The ideal rainfall occurs weekly and comes in one-inch increments. That is enough to saturate the soil down through the depth of plant roots.
Resources
- South East Regional Climate Hub (SEARCH)
- National Ocean and Atmospheric Administration
- National Weather Service
Transcript
JENKINS
Remember last winter? All that ice? I lost a couple of my fave plants so I wanted to know what we could expect this year. Last fall, I talked with Dr. Steve McNulty to get an ideas of what’s in store for this year’s weather.
McNULTY
I’m Steve McNulty. I’m a USDA Director of the Southeast Regional Climate Hub located here in Raleigh, NC. I’m also a Research Ecologist with the US Forest Service.
There’s all kinds of weather patterns that occur. There’s natural variability that’s always out there. And then there’s other types of variability that’s out there that’s more cyclical. And one of the things that’s coming out now of cyclical nature is something called an El Nino. An El Nino is an event by which you see warming in the Pacific. Its off of South America and as that water warms at the equator it impacts the climate here in the southeast United States. The area of Florida Georgia, Alabama, but even up here in the Carolinas we are going to see some impact.
JENKINS
So what will our weather look next year?
McNULTY
Well it may even start before that. We think its going to start late this fall and once we are into the early part of 2016 we are expecting to see much cooler than normal weather. So we may see more snow for example than we normally see. It definitely will be cooler and much, much wetter. So these El Ninos have a tendency to change the type of circulation flow that we are seeing and in the case of the southeast it makes it cold and wet. So over the course of this winter, we’re likely to see, for example, greater impacts of flooding, intense rains. By “intense” we mean rainfall events that are more than 2” in a 24-hour period. So these are the kinds of rainfall events that can have negative impacts on gardens. So if you have a garden and its not covered, you don’t have a cover crop on it, after you last harvest is done if you were to plant rye or some other type of cover crop that helps protect the soil. If you don’t do that and you have exposed soil when you have that type of rain you have a much greater chance of having some type of erosion of that soil. So that’s one of the things that we are concerned about both from a gardening point and an agricultural point as well.
JENKINS
What happens then for the rest of the year?
McNULTY
The major impact of El Ninos are in the winter months. In the spring what we are likely to see is still a period of wet weather. That will dissipate. Into the summer we’ll see more normal weather. We won’t see particularly hot weather like we did in 2015. The year 2015 from a global standpoint was the warmest its ever been recorded. June, July, August of 2015 is a record. We broke records this year. In North Carolina it was hot, it wasn’t super hot relative to other times, other years. But globally it was extremely hot. Next year, in 2016 we’ll probably see something that is normal for our area —and relative to 2015 almost seeming cooler. But we won’t see a lot of heat in the summer of 2016, at least that’s the forecast now. If anything we may see a little bit of drying. So we may not have severe drought, but we may be a little drier than we normally would be.
JENKINS
Now parts of our state have already been in drought conditions.
McNULTY
They have. In the western part of the state we’ve seen relatively moderate drought. Which is unusual. That’s an area that generally receives pretty good precipitation. That has persisted over much of the summer and early fall of 2015. But one thing I think is important to note is even when we talk about rain events, if for example during the summer months we could expect to have 20” of rain in the Raleigh area of North Carolina, that rain timing is really important. Over the summer period and getting 20” of rain, if that comes in 1” increments that’s perfect. That wets the garden, it wets the lawns, it’s saturating. Not so much as it causes over land flow or flooding. If we get more than that two things can happen. One, is that additional rainfall isn’t used by the soil. It flows either over the top of the soil as over-land flow and causes flooding. It also can cause soil erosion. But more importantly, its sort of wasted because it doesn’t give any additional help to watering the soil. If those type of rain events come in those big chunks, you still may get 20” of rain but you may get fewer rain events. So you can actually have periods of drought in between what would be considered an average rain year.
JENKINS
There’s a lot of discussion out there about climate change and, frankly, I get confused about who to believe. Where can people go for credible information about climate change?
McNULTY
So the USDA has established, seven, what they call Climate Hubs. Secretary Vilsack, the Secretary of Agriculture, is very concerned about the long-term sustainability of America’s garden and productivity of our farms and forests. So establishing these climate hubs they’re designed not to really do new research but take all of the great, existing research that’s already out there and make it more applied and make it more available for common people who don’t have a scientific background to use. So there are numerous websites, we have a website with the Southeastern Regional Climate Hub that I would encourage people to come and visit (http://climatehubs.oce.usda.gov/southeast ). That has everything from links to other information databases and tools that you can use to assess what type of impacts you may see in your garden. There are models out there and other types of data products such as AgroClimate. Which will show you things like how an El Nino will impact productivity in certain areas. Provide alerts if there are going to be frosts, late season frosts, or drought alerts. There’s just a wealth of information out there.
JENKINS
Okay, assimilating all of this information and looking out over the coming year, what recommendations would you make to gardeners?
McNULTY
Gardeners are really fortunate in a lot of ways relative to farmers because its generally a smaller area and we have options as gardeners that we wouldn’t have as a farmer. So there’s certain things we can focus on to increase the resiliency of our gardens for things like drought. One of the best things you can do as a gardner is to add organic matter to your garden. Organic matter is a wonderful compound wether its compost or peat moss. Anything you can add that would help retain that water in the soil is really useful. So as we see the weather becoming more variable and we have more of these intense rains and we go longer periods with no rains, that organic matter in the soil really helps to absorb that water and maintain it there during those longer periods of what might become drought. So that would be the first thing I would recommend to any gardener is increase your organic matter. That’s something that a gardener can do that would be too costly from a commercial standpoint.
Other types of practices would be to mulch, anything you can do to try to keep the weeds from coming up and the soil moisture from evaporating out is a great idea. A lot of these weeds that we are seeing now respond better than non-weed species to this climate variability and these types of extreme conditions. Weeds are designed to take advantage of disturbance that’s where they grow —sides of roads, these really harsh conditions where nothing else will grow you’ll find weeds growing there. They’re designed to be very hardy. So as we enter a period where the climate becomes more variable weeds are going to do really well. So anything you can do, wether its Integrated Pest Management, wether its mulching, wether its diseases resistant varieties of crops, fruits, vegetables or flowers, that’s really useful. Those are all things you can do as a gardener that are going to lessen your risks of the types of stresses that we are likely to see not only this year but as the stress continues for future years.
JENKINS
You can find links to the USDA’s resources on my website, absentee-gardner.com. So far Dr. McNaulty’s forecast has been spot on but I’ll check back in later this year and see if, in fact, things were colder and wetter. I’m Lise Jenkins and I’ve been absent from my garden in Durham, North Carolina.
The Absentee Gardeners 