THE LEAFLET
Tree Care During a Drought: A Conversation w/ Western Arborists (Part 2)
This is part 2 of our 3-part conversation with Matthew Fried, Gordon Mann and James Scheid about how the prolonged drought in California is affecting their tree care.
Have you noticed premature die-off of newly planted trees because of the drought conditions? Significant die-off of mature trees?
MF: The rules are still the same: newly-planted trees need water regardless. The fact that there’s a drought certainly means that its more important, but if they’re not getting water even in the best of times, it’s going to be very tough for them. It comes back to the importance of only planting where you have people who will do the watering or where the city is willing to do the watering.
For mature tree die-offs, I don’t think you could say it’s the drought. Poor tree health predisposes the trees to other types of problems, and certainly drought is a compounding factor, but I don’t feel like we are doing considerably more removals now than my predecessor did. Though we doe have a lot of redwoods that look crappy and are crisping up,;curling around the edges and really struggling.
We also have a bunch of species – our maples, our lindens, our ash – that haven’t even leafed out yet. They are still alive, but they haven’t leafed out and it’s the middle of June, and what people are proposing around here is that it’s because we didn’t get enough cold days this winter for the buds to properly set.
GM: Yes, we’ve seen [die-off] in a couple of areas, in some of the natural areas. Pines that are dying out because of pine bark beetles coming more frequently, which weren’t tempered this winter due to a lack of cold weather. The redwood is a tree that is overplanted and when it comes to water supply, there has been some redwood die-back due to this. A lot of trees that are planted in lawn areas haven’t been getting their water from the lawns and those trees are experiencing dieback or are dying completely.
How are you balancing the message of the importance of watering newly planted trees with water conservation and restrictions to residents?
MF: I am reminding them of all the benefits that trees provide, and that watering their trees is a good investment. Turning off the sprinklers on that lawn and focusing that water on the tree is going to pay off better dividends in the future. Also, that there are different ways to water that tree. You can use the bathwater as your shower heats up.
We are doing a lot of the watering ourselves for the city and public space trees and we’re really trying to use e reclaimed, recycled water from the sewage treatment plant. As a second choice, we are also in touch with the Water Authority who regularly flushes fire hydrant systems to get sediment out and that water typically gets wasted, so we’re working on ways to capture that water whenever they’re flushing the hydrants.
GM: It doesn’t matter if you’re in a drought or not when you plant the new tree. Container, ball, or burlap, we know where the root system is. It’s right there where the tree is and if you don’t water it, then the tree is going to. Most of the soils in typically planted trees is right there in the root ball and it’s very porous soil. I also think that if you don’t want to water trees, then it’s a waste of money to plant them.
JS: We are trying to encourage people to not take the frightened approach of not planting anything, but rather emphasizing that trees actually give back and enrich the soil.
It’s necessary for us as a program to make sure that people are framing trees as viable pieces of the landscape. We do get questions from people like “Hey, we’re going through a drought. What should I be doing with my trees?” Well you should still be concerning yourself with new trees, but also with your mature trees. They’re gonna need water now.
People also want to know: “Can I still plant trees? If, so what kinds should I plant long-term that are drought tolerant?”
Other folks use recycled or grey water on their landscapes and want to know how that may affect certain species over others.
With mandated water restrictions about to be, or already in, place, what are some steps that arborists in your region are taking to help preserve water and save existing trees?
GM: Mulch. Mulch is the best thing you do to cover the soil. Consider the soil like a sponge. If you allow the sponge to go bone dry in your sink and pour water on it, it’s gonna run off. If you moisten it lightly and pour water at a very low volume over the sponge it will actually soak up the water.
JS: Making sure trees are mulched and that other vegetation around the tree is reduced or eliminated.
What are the mandated restrictions that are about to start in you city?
MF: We are watching very closely every day. I think the trees themselves are valued by the water authority and get more leniency whereas the fields, the turf and the shrubs, are where they are cracking down. There are also increased fees. The cost of the water is going up.
Really the only time trees are in peril from those regulations is where their in-ground irrigation is tied into turf or shrubs and all they’re getting is that turf-shrub water, which is being cut back.
GM: There are new water restrictions pretty much everywhere. The governor has said that in California there should be a 30 to 35 percent reduction in water use. The challenge is that water agencies have changed their own rules. Some say water one day a week. Some say two days a week. Some say three days a week. Some agencies might enforce it really strictly, some agencies might be letting it go. So that’s a challenge for water conservation.
What is your biggest fear with this drought?
MF: I think the loss or decline of our mature trees, which are in our parks and residential areas. We’ve put a lot of time and investment into those and they have a lot of potential to pay off, but they will get shorted [not watered as much] by the temporary concern about the drought. All the sudden people are getting the message “save water, don’t water your trees” and then we let a bunch of trees die that would have helped recycle water in the future and would have continued to be mature assets for the city.
GM: My biggest fear is that people still won’t manage their water like their bank account. You only have so much water. You have to figure that they’re gonna wait, and think it’s gonna be over with a little bit of rain. It’s not a drought issue; it’s a water supply issue. We have twice the population we had in the 1970’s [during our last big drought] and people haven’t learned from it.
You go to some places in southern California and they’re still watering lawns. They’re living in a desert and they’re watering lawns. It’s just an insane approach to water management! The water agencies don’t help because they raise prices as a penalty for heavy usage, many people will pay the higher fines and not be practical about their water management.
People will think “Oh, I can live here and I want redwoods,” so they plant redwoods and it’s a mistake. If I can afford a Peugeot, I’m not going to go out and buy a Cadillac because I want a Cadillac. But people will finally have to get more practical with their landscape.
JS: The fear that people won’t plant anything is one concern, and how that can get carried away like when we have wildfires pass through and people want to remove all vegetation from their property when there’s not any potential risk.
Overall, how much are we learning from historical occurrences like this? Eventually, the thought is this drought will pass, in maybe a year or two. But will we then go back to exploiting our water use as much as possible; will we still frame trees as a vital part of our landscapes or will we continue to develop these natural areas without nature in mind?
Comes down to man versus nature and trying to stay nature-focused in the development world.
There have been plenty of articles about the drought and the damage it has caused some of the state iconic tree species, like the redwood. But not that many about other tree species. Why do you think this is?
MF: Maybe redwoods have been over-planted in areas that are outside of their natural environment. San Mateo is warmer and dryer than the climate just a couple of miles west over the hill where redwoods might do better, or Monterey Cyprus might do better, and they would get reasonably moist soil and the fog that comes in which we don’t really get here. Before the water restrictions, you would plant a redwood and water it without problems for its entire life. Maybe that’s catching up to us.
GM: Probably because the redwoods are very popular. Where they are getting affected they’re outside their native range and they’ve been pampered outside their native range. Another issue we see with redwoods in the Central Valley area is they’re using recycled water and the recycled water is knocking back the redwoods because they’re not spray salt tolerant, reflecting water with high salt content, which can damage the trees.
JS: The coast redwood is such an iconic tree in California. It’s such a huge tree, very durable and very long-lived. But it does so because it lives in a confined space. It’s not spread throughout the state.
I think we as state think that: “oh it’s a tree and it can grow anywhere,” but they don’t consider its natural range. We see this with our tree planting grant. People want to plant trees like redwoods, ash, maple, very water thirsty tree species, in areas like the Central Valley.
That idea of having an iconic tree and planting it wherever you are, they’re forgetting the science of it and they don’t realize that it doesn’t grow in certain areas.
Check back on Thursday (7/16) for the conclusion of our conversation with Matt, Gordon and James as they discuss what they’ve learned about the resiliency of trees.