Does it do any good to water a large tree?

All the trees in my yard and the ones on either side were planted in 1925 when it was one large lot. A mix of maples and oaks. The maples are apparently near the end of their lives as numerous ones have died. They all die the same way. The large limbs die off one at a time then finally the whole tree after several years. Eventually the limbs drop but it takes a long time before the man trunk topples.

The largest tree is right in front of my house. It is about 110 feet high and is bifurcated. All the maples are bifurcated. If one of the main trunks fell it could take out my house or the neighbors so I have an interest in keeping it healthy and it seems just fine. It is an open, airy tree and that helps.

Is there any benefit to watering the base during dry spells? The main clump of roots is about 8 feet across and sometimes I water it but I wonder if watering the surface does any good? I’ve seen systems designed for watering trees that use a hollow spike driven into the ground to get the water deeper.

My street is lined with elm trees about 40 yrs old. They are all about the same size and look similar in health and fullness. The watering habits of the residents is vastly different but it doesn’t seem to be visible in tree health. I suspect that watering as it leeches down spreads out and tends to average out over a large area and if that is the case the average amount of watering is reflected in the trees on my block. I don’t see how a tree would know the difference between rain and watering. If I had a large plot of land I would supplement the water during dry periods.

There might be. My mom had a large oak tree in her back yard. Her and Dad decided to enclose the patio and convert it to anothet room and built a new patio. This killed the oak eventually(took a few years) because the pavers for the new patio covered so much of the root network. So that water tube thing you mentioned might be good. Maybe get an arborist to take a look.

ETA, I have it in my head that you’re supposed to water a tree in circle centered on the trunk with a circumference slightly larger than the canopy of the tree

I do volunteer work for a non-profit that plants street trees and then cares for them for the first three years, so I have a little background in this issue.

The organization recommends regular watering (20 gallons once a week in a slow release watering bag like this) for the first 3 to 5 years, to establish a good root system. Once the roots are established, the tree should be able to get enough water from groundwater resources in most climates and areas. Supplemental watering can help for serious drought or other dry conditions, as long as the water is delivered as deep as possible, so the roots go down instead of along the surface.

For the tree in front of your house, or any other tree that would cause serious damage if a large branch fell, I strongly recommend hiring a certified arborist to diagnose and prune the tree as needed (“prune” in this case could mean as much as cutting off the branch that is threatening your house). You really do need a certified arborist for this, it takes a lot of education and experience to be able to handle a job like this. You may end up paying a few hundred bucks (or a lot less) but you may save your house, and you should get peace of mind about this tree.

Generally speaking, there isn’t a whole lot of point in watering a large tree, unless you’re prepared to use a really large quantity of water. A light sprinkle can encourage the growth of shallow surface roots- as the water won’t soak in very far, so that’ll be where the water is. That’s not a good thing, as these shallow roots will dry out faster, and will then basically require repeated watering to stay healthy.

I tend to think that if a proper established large tree isn’t able to get enough water on its own, you’re probably not going to be able to fix that- the quantity of water it’d be getting through (or would be getting through it?) could run into the hundreds of gallons per day - if the bit you’re sprinkling round the base is going to make a real difference, the tree’s probably doomed anyway.


A large tree adapted to a particular climate and which is in good health, should be able to withstand periodic drought just fine. It may drop leaves earlier than usual under drought stress.

A knowledgeable tree service may have useful recommendations for maintenance like core aeration of soil, if there’s a problem with compaction and water running off instead of soaking in.

I once owned a house built in 1928. I suspect the large weeping birch tree in the front yard was likely planted around then. Fast forward 50+ years, tree is looking sparce in the centre. Wrapped a soaker hose around the base and let water slowly soak into the ground several days. After a few weeks the tree made a remarkable come back.

We had a really bad drought a couple of years ago. The next summer, i lost two trees and some old, established shrubs. (And also some newer shrubs.) It hadn’t occurred to me to water the trees, and i suspect if I’d watered them deeply once or twice during the drought they would have survived.

Routine watering seems like a bad idea, though. If the tree can’t survive on the usual amount of rain, you are better off with some other kind of tree.

If your neighborhood is losing a lot of maples, i wonder if there’s some insect or pathogen to blame. I second the suggestion to hire an arborist.

As a rough guide, a tree has as much root growth extending underground as it has branches & leaves growing above ground. So watering anywhere under the tree canopy will get to the roots.

But deep watering once a week is better than shallow watering every day. Put your water hose on slow, and let it run all night long, once a week during a drought, or when a tree is stressed by disease, insects, or storm damage. Otherwise, in normal times, mature trees shouldn’t need such help.

Sorry to mention it, but could a large tree this close be sucking water out from under your house and causing subsidence?
It might be worth getting a tree surgeon to take a look…

No, it wouldn’t cause subsidence.

I would get a certified arborist out for a look though.

That’s what I was going to say… and that if it’s got roots 15 feet deep, it’s likely dealing with different water availability than surface plants like grass.

It’s not uncommon around here in the height of the annual summer drought (it rains very infrequently from about mid-June through mid-September) for grass to be brown and dormant, while trees are green and happy. My guess is that they’re drawing water from much deeper underground than the grass, and that water isn’t as sensitive to surface weather variations.

That said, if I felt the need to water a tree, my goal would be to get the water as deep as I could, and I’d do it by a very slow process- maybe a 1 gal/hr dripper for 10 hours or something like that.