Chestnut trees are quickly disappearing in the US because of chestnut blight, but there are still a few wild stands around and you can also plant chestnut trees in your yard. If you have a chestnut tree or are planning on planting one, you may wonder how much water they need.
Chestnut seedlings need around a gallon of water per week. Make sure to deeply and slowly water your chestnut tree in a circle (not directly on the tree bark or base) so that all of the roots get watered. Older chestnut trees can be watered weekly during dry spells.
Below we’ll go over how much water both young and mature chestnut trees need so you can have a happy, healthy tree in your backyard!
What Conditions Do Chestnut Trees Need In Addition To Water?
Let’s talk about what conditions chestnut trees prefer first. If you plan on planting a chestnut tree, you’ll want to pick the right location OUTSIDE of watering them properly. If you already have a chestnut tree growing in your yard, you may be interested to know what conditions will help it thrive outside of watering~
Not all chestnut trees are the same. There are four main species of chestnut tree:
- American Chestnut
- Japanese Chestnut
- Chinese Chestnut
- European Chestnut
The American chestnut and Chinese chestnut are the two most popular chestnut trees when grown for their fruit. When we say fruit, we are referring to the chestnuts!
So, what conditions are best for chestnut trees that allow them to make the most use of the water they get?
Best Soil Condition For Chestnut Trees
Chestnut trees are drought tolerant, but they don’t prefer to be in super dry or wet soil. Their root system must be able to penetrate the soil, meaning it can’t be too thick either.
According to the State University of New York, chestnut trees prefer well-drained, slightly acidic, sandy soils. They can survive in clay soils, but their growth may be stunted, as the roots cannot penetrate the soil as well as sandy soil.
The ‘well-drained’ part of the description is important in relation to our watering schedule, which we’ll discuss more later. If the soils hold too much water, the chestnut tree can develop root rot, which is often devastating to the tree, especially if it’s young.
Best Light Conditions Chestnut Trees Thrive In
The light required for chestnut trees will depend on what you are planting the trees for. Do you want to harvest the chestnuts or are you just looking for a nice shade tree?
If you want to increase nut production, plant your chestnut tree in full sun. However, if you just want your tree to grow as fast as possible, it’s recommended to give it some shade throughout the day – about 1/4th of the day should be in shade.
One important thing to remember is if you start your chestnut tree in a pot indoors, be sure to harden the plant to the sun before placing it outside. Slowly introduce the seedling to the sun for about two weeks before letting it sit in full sun all day.
Best Fertilizer For Chestnut Trees
Using fertilizers will help improve growth and can give your chestnut tree an extra boost to keep it happy and healthy.
It’s not recommended to fertilize a newly planted tree. Instead, wait until at least its second season, which helps the tree put as much effort as possible into establishing a root system in its first year. Fertilizers can encourage the tree to make leaves instead of establishing roots.
According to the Connecticut Agricultural Experiment Station, use a fertilizer with a mixture of 5-10-5 or 10-10-10. These numbers are the N-P-K ratio, meaning nitrogen, potassium, and phosphorus.
A fertilizer like Southern Ag’s All Purpose Granular Fertilizer is a superb choice for chestnut trees. It comes in a 5-pound bag and can be spread over the planting area and then watered in.
It’s recommended to use 1 pound of fertilizer for every year of the tree’s age. So, if your chestnut tree is 3 years old, use 3 pounds of fertilizer.
If you don’t know your tree’s age, you can apply one pound of fertilizer for every inch in diameter of the tree’s trunk.
How Often Should I Water My Chestnut Tree?
We’ve talked about the soil, light, and nutrient conditions that promote the best growth for chestnut trees. Now it’s time to buckle down and get into the details about how much you should water your chestnut trees.
The exact chestnut watering schedule will depend on a few different things:
- Age of the tree
- If planted from seed
- If planted from a pot grown indoors
- Soil conditions
- Light conditions
Don’t worry, we’ll weave this all together when we talk about your watering schedule. No matter what your situation is, we’ll cover it!
The Older The Tree, The Less Water It Needs
It’s just like us if you think about it! When we’re young, we can eat and eat because we’re growing. As we age, we eat less.
Trees are the same. As young seedlings, trees need a lot more help with watering and nutrients to promote growth both above and below the soil.
The roots need to establish quickly, with the taproot reaching directly down to keep the tree stable from high winds, and lateral roots reaching out to find water. Above the soil, shoots need to establish quickly to promote leaf growth, which will help with photosynthesis.
This is a fragile time for a chestnut tree. Having soggy soil or soil that is too dry will stunt growth and make it hard for the tree to establish itself.
Mature chestnut trees would benefit from .5 – 1 gallons of water per tree, per week. However, that is a general guideline and may change based on the soil or sun conditions where your chestnut tree is planted.
As the chestnut tree ages and establishes itself, you can just let mother nature take care of your tree! That being said, during droughts you may have to give your chestnut tree a drink here and there so it doesn’t dry out.
Most of the time, you can let mother nature take over after two years. But until then, it’s a good idea to water your newly planted trees. If you have an established chestnut tree, you shouldn’t need to water it unless there is a draught.
Chestnut Seeds Need Less Water Than Transplanted Seedlings
For homeowners who want to plant a chestnut tree, you have two broad options. You can either plant them from seed or transplant them from a pot as a seedling.
Most of the time, you are going to transplant them from a sapling you buy at your local farmer’s market or arborist. However, some like to start from the beginning and plant chestnut trees from seed.
If you decide to go the seed route, you’ll want to avoid over-watering the seed. This can rot out the seed before it has time to sprout.
You can keep your seed refrigerated (above freezing) for a few weeks before planting if necessary to wait for proper weather conditions.
Some things to keep in mind if you decide to plant your chestnut tree from the seed:
- When to plant: Plant your seeds in the spring as soon as you can work the soil.
- Use good soil: According to Penn State University, a mixture of peat, perlite, and vermiculite in a 1:1:1 ratio is best for chestnuts.
- Seed depth: Plant your seeds 1 inch into the soil, with 4 inches of your planting soil beneath the seed and 1 inch covering your seed.
- Water lightly: Water the soil until it is wet without soaking it.
Chestnut Seedlings Need The Most Water
Growing your seeds indoors in the winter and transplanting your seedlings outdoors in the spring is a perfectly good way to establish a chestnut tree in your yard!
Chestnut seedlings, which are newly formed chestnut trees, need about 1 gallon of water per week. You should deeply water around the tree in order to make sure you cover all of the roots. Mulch goes a long way in keeping the water retained around the tree so it stays properly watered.
You can start growing your chestnut tree in January or February. This will give your seedling enough time to grow and be ready for re-planting in the spring.
If you decide to take this route, keep the following in mind:
- When to transplant: Unlike seeds, which you can plant before the last frost, seedlings should only be transplanted outdoors once the danger of frost has passed.
- Potting Soil: Our 1:1:1 ratio for seeds won’t work for a seedling. You’ll want the soil inside your pot to be more fibrous than nutrient-rich. Something like Miracle-Gro Orchid Potting Mix Coarse Blend will work great.
- Outdoor water requirements: As we said, seedlings need a lot more water than seeds. Give your chestnut seedling at least one gallon a week, but you’ll probably need a bit more (maybe 2 or 3 gallons.) You may need to increase this if rains are infrequent.
- Give your tree space: Remember, your seedling is a delicate little thing now, but it will eventually grow into a whole tree! Don’t plant your seedling near your house and make sure you give it enough space from other established trees. Chestnuts can tolerate some shade, but they thrive in the sun.
Soil Conditions Can Affect Your Chestnut Watering Schedule
The type of soil you plant your chestnut tree in will determine a lot about your watering schedule.
According to the University of Maryland, there are three main types of soil:
Loam is another type of soil, which is a combination of these three soil types. Don’t worry, you don’t have to send your soil out for testing to determine what type of soil you have.
You can use a few methods to figure this out yourself. Just be prepared to get your hands a little dirty! The ‘feel’ method is one way to tell what type of soil you have. To do this, follow the steps below:
Step 1: Add soil to your palm and add water until moist but not soaking
Step 2: Knead soil until it feels like putty
Step 3: Can it form into a ball?
- Yes – Clay, silt, or loam
- No – sand
Step 4: If it’s not sand, form a ribbon by pushing the soil with your thumb so that the ribbon goes over your pointer finger. Note the length of the ribbon before it breaks under its own weight.
- Less than an inch – silty loam
- 1-2 inches – clay loam
- Greater than 2 inches – clay
You can divide those categories further into ‘sandy loam’, ‘silty loam’, or ‘clay loam’ by feeling for the grit in the soil. The more gritty, the more sandy. The more smooth, the more clay-like.
Another option is to make use of the United States Department of Agriculture Web Soil Survey. You can search by using your address and as long as a survey has been done in the area, it will have a soil profile for you to download.
For chestnut trees, you’ll want sandy or sandy loam soils for the best growth and nut production. Sandy soils have the largest soil particles, meaning they will provide the BEST drainage because there is room for water to move through the particles.
Now, just because you have clay soils does not mean you can’t plant a chestnut tree. However, you will have to be careful about over-watering. Clay soils hold water far longer than sandy soils.
In general, the more sandy the soil, the more water your chestnut tree will need. The more clay-like soil, the less watering.
So, if clay soils mean less watering, wouldn’t that be better for chestnut trees?
Not really. Clay soils have tightly packed particles, which make it difficult for roots to poke through. This can stunt the growth of your chestnut tree and limit nut production. It’s best to stick to sand or sandy loam soil.
Also – do some internet research and see if your local township has some information on your town or county’s main soil type. You’ll probably be quite surprised!
Light Conditions Affect Watering Schedule
Sunlight is an important factor in a tree’s health. A shade tree will not do well in full sun, and vice versa. The amount of sun your chestnut tree receives is yet another factor affecting your watering schedule.
An article in the Journal of Forest Ecology and Management found the greater the exposure to the sun, the more water chestnut trees need to develop new roots and shoots.
The idea behind this is that if the tree is in full sun, it’s more actively going through photosynthesis. For photosynthesis to happen, the tree needs three things: sunlight, carbon dioxide, and water.
The higher the photosynthesis rate, the more water the tree needs.
If your chestnut tree sits in full sun all day, increase your watering schedule to make sure your tree is getting enough water to promote healthy growth.
Conversely, if your chestnut tree is in partial shade, consider cutting back on your watering schedule.
How To Maintain A Chestnut Tree Long-Term
We’ve gone over the core basics of planting a chestnut tree. We went over the soil, light, watering, and nutrient requirements.
So, what else can you do to take care of your chestnut tree?
Besides proper watering, soil conditions, and light conditions, you’ll want to keep a lookout for some of the following problems:
- Pest control
- Weed control
- Critter control
Insect Pests Of Chestnut Trees
There are plenty of six-legged pests out there that love chestnuts just as much as we do! They mostly go after leaves, sap, and sometimes the nuts themselves.
A few of the most common insects that affect chestnut trees include:
- Asian Chestnut Gall Wasp
- Japanese Beetle
- Ambrosia Beetle
- Aphids (and other soft-bodied insects)
- Gypsy Moth
- Orange-striped Oakworm
- Yellow-necked Caterpillar
To combat these problems, you can buy pest control sprays specific to these pests. However, these can be detrimental to pollinators and aren’t recommended unless you have a serious pest problem.
According to the Journal of the American Chestnut Foundation, allowing natural predators like wasps, birds, and spiders to flourish around your tree is a great way to keep pests under control naturally.
You can also hand-pick caterpillars and other obvious insects off your chestnut tree.
Control Weeds Around Your Chestnut Tree
Controlling weeds around your chestnut tree is especially important during the first few years of your tree’s life.
When a seedling chestnut tree has to compete with grass and other weeds for nutrients and water, it can cause stunted growth and limit root growth.
While you can use a weed removal mixture, I recommend just pulling the weeds out near your tree by hand. It’ll be better for the tree and surrounding soil!
Once the weeds are cleared, you can apply mulch to prevent future weeds and grass from growing. This has the added benefit of helping to retain moisture.
Control Critter Damage Around Your Chestnut Tree
Deer and rodents will love you for planting a chestnut tree. Unfortunately, they will not be as careful around your tree as you are.
Deer can damage chestnut trees by rubbing up against the bark and eating the twigs during the winter when food is scarce. Rodents can damage chestnut trees by eating the bark towards the ground and by digging up chestnut seeds before they bloom.
To help protect your chestnut tree, you can purchase a tree protector. You’ll want to make sure your tree protector is breathable, such as Voglund Nursery’s Mesh Tree Bark Protector Guard.
Solid tree protectors trap warm air in them, which can cause your tree to stop hardening off for winter. Solid tree protectors also offer wasps and other pests a free hotel where they can tear into your chestnut tree’s bark.
Final Thoughts On How Much Water Chestnut Trees Need
As we wrap this article up, let’s recap some of the most important aspects of keeping your chestnut tree watered.
- The older your chestnut tree, the less you need to water it: Once your chestnut tree reaches about two years of age, you can let mother nature take over unless you face a draught.
- Chestnut seeds need less water than seedlings: Chestnut seedlings need about a gallon of water per week. Chestnut seeds shouldn’t be watered until they begin sprouting, as this can rot the seed.
- The sandier the soil, the more water you need: Sandy soils have the largest particles and therefore allow the most space for water to drain. It has the least water retention. So, the sandier the soil, the more water you will need.
- The sunnier the conditions, the more water you need: If your tree sits in a shady spot, you can expect to need less water. If your chestnut tree sits in the sun all day, you may need to increase your watering schedule.
You can have the perfect watering schedule and still run into problems with your chestnut tree. Watch out for pest insects, weeds, and browsing critters as well.
It’s also important to note that chestnut trees require cross-pollination to produce chestnuts, meaning you need at least two chestnut trees to produce any nuts.
Have questions about other trees in your yard? Head on over to Tree Journey to start your journey today!
Griffin, G. J. (2000, February). Blight Control and Restoration of the American Chestnut. Journal of Forestry, 98(2), 22-27.
Heavren, S. (2020, Fall). The Perfect Tree: The American Chestnut Tree in American Culture, Economics, and Science in the Nineteenth and Twentieth Centuries.
Mota, M., Marques, T., Pinto, T., Raimundo, F., Borges, A., Caco, J., & Gomes-Laranjo, J. (2018, April 30). Relating plant and soil water content to encourage smart watering in chestnut trees. Agricultural Water Management, 203, 30-36. https://www.sciencedirect.com/science/article/abs/pii/S037837741830088X
Wang, G. G., Bauerle, W. L., & Mudder, B. T. (2006, May 01). Effects of light acclimation on the photosynthesis, growth, and biomass allocation in American chestnut (Castanea dentata) seedlings. Forest Ecology and Management, 226(1-3), 173-180.