How To Grow Black Cherry Trees From Seed

If you’ve ever wanted to germinate Black Cherries to grow your own trees, you’ve come to the right place. I’ve grown dozens over the years, and have even tested variations of my process to see what works best. In this short guide I’m going to show you exactly what to do for harvesting the cherries, preparing and planting the seed, and other tips I’ve learned to raise your germination rates.

Harvesting Black Cherries for seed

The fruit on Black Cherry Trees will begin to ripen starting in mid to late Summer^[1][2]. Start picking Black Cherries from trees as the fruits begin to turn a dark purple-black color. These will be the ripest, and it’s important to get to them before the birds. I just gather them into a little baggy in mid-Summer.

Preparing/saving the seed

To prepare the seed, you just need to squeeze out the seed from the cherry. Just pinch between your fingers and gently squeeze out the nut. Then rinse these off in tap water to clean them, and pat them dry. They can be stored in a sealed container for some months before you go to sow them. Note – if you intend to cold stratify in the fridge, then before you do so you should first sterilize the seed in a 10% bleach solution before placing in moist sand or a moist double-paper towel.

Cold Stratify or Winter Sow?

Since Black Cherry seeds have a cold-moist stratification requirement to germinate, we’re going to have to subject the seeds to some kind of cold-moist environment for a prolonged period of time (official references state 120 days^[3]). This can be done by using our refrigerator, or planting the seeds in a container that we store in a cold location during the winter. Personally, I prefer to Winter Sow as it is just easier with less headaches. But, I will describe both processes below.

Now, I need to inform you that there is some other information regarding stratification. Some papers claiming to have big successes with warm stratification followed by cold. This is an interesting discussion, and I’ve tried both. I can tell you though, just focus on the cold stratification and you will have success. I have actually tested this, and you can see my results near the end of this article, if you are so inclined to read it.

Cold stratifying in the fridge

To cold stratify the Black Cherry seeds in the refrigerator, you will need clean seeds, some moist sand and a baggy – or using two full sheet paper towels that are thoroughly moistened.

Stratifying with a paper towel

1. Sterilize the seed by soaking in a 10% bleach solution for 5 minutes. After wards, rinse them off with clean water.
2. Soak the seeds in tap-water for 24 hours at room temperature before cold-stratifying. This helps the seeds stay moist, and moist seeds are happy seeds.
3. Lay out two paper towels on top of one another and spray it with water. You want it thoroughly moistened but not sopping wet.
4. Place your seeds on one quarter of the paper towel and then fold it over twice.
5. Carefully flip it upside down, and old it over the other way so that the seeds are sandwiched between four layers of paper towel.
6. Place the moist paper towel into a zip-lock bag and label & date it.
7. Store this in the refrigerator for four months.

Stratifying with moist sand

To cold stratify with the moistened sand, simply take play sand or vermiculite and get it thoroughly wet. Wring it out by hand, and then layer it 1/2″ thick on the bottom of a Tupperware or plastic container. Place your seeds on top of this layer, then add more moist sand so that the seeds are level or just buried. Place a lid on the container and put it in the fridge for four months.

Winter Sowing Black Cherry seeds

My preferred method is to just winter sow Black Cherry seeds. I like it better than using the fridge because there is basically zero risk of mold or other pathogens attacking the seeds.

Take care of the above factors, and winter sowing Black Cherry seeds will be easy. The steps are below. If you click on an image, it will enlarge.

1. Fill a tall container (at least 6″ deep) with moistened potting soil, leaving a 1″ gap at the top.
2. Tamp the soil firm, but not hard.
3. Place 2-3 Black Cherry seeds on top of the soil.
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4. Bury the seeds in 1/4-3/8″ of moist potting soil.
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5. Keep the containers in a cold location that is protected from squirrels and rodents. And do not let the containers freeze solid.
6. Do not let the containers dry out. I have found the best practice is to just fill up a watering can and add a small amount of water each week. I do this on Sundays, as I just ‘remember’ it. It becomes habit after a while.
7. When Spring is approaching, the containers can be moved outside in a location that gets morning sun and afternoon shade.

When to expect germination

Black Cherry seeds germinate in early Spring. I’ve had them germinate as early as the first week of April in zone 6, when we still get the occasional freezing temperature at night.

Can you separate seedlings?

If you planted several seeds per container and they all germinated I can tell you that yes, it is possible to separate the seedlings. You should really head over to my post on separating seedlings for a detailed lesson. But, I will a summary of the steps now.

First, prepare more containers. You want to have them ready to go. So, find containers that are at least as deep as the one you will be transplanting from (as the roots likely reach the bottom already). Put a small layer of moist potting soil on the bottom.

Next, carefully remove the cherry tree seedlings from the container and gently (very gently) pull apart the roots. It really helps to massage the container prior to doing this, and to sort of have it upside down. I place my hand over the top and tip it upside down, but have my fingers spread apart with the trees in the gap.

Now, replant your seedlings in your prepared containers. Gently hold a cherry tree in the container so that the trunk/soil interface (depth) will be the same as when you dislodged it. Then, carefully and gently sprinkle potting soil into the container. Try to compact the soil a little bit as you go with your fingers, but be gentle! Do this until the soil is at the level it should be.

Water the containers and keep them indoors for a week. Then, slowly transition them to sun conditions over the course of another week or two. The root system has been thoroughly disturbed, and your plant needs that time to reattach it’s roots so they can take up water/nutrients.

Establishment

To establish a young seedling in your yard isn’t hard, but it can be made easier depending on when you transplant them. The seedling root will develop fairly quickly, growing 6″ in just 30 days (in my experience). And you should be able to transplant them by mid-Spring.

If however, you get too busy and it starts getting really hot, like 70-80F for the daytime high temperatures, you should probably just keep it in it’s pot until late summer or early Fall. The cooler temperatures won’t stress the tree, and the soil will be more consistently moist. I will actually plant trees right up through December – if the ground is not frozen, you can plant.

Protecting young trees

One thing you should definitely keep in mind is that while we love our trees, the deer and rabbits do too! In winter, they view them as a source of food. Rabbits will chew on the tender bark while Deer will just eat the sapling. Actually deer will do so year round. So, you should really consider purchasing a tree shelter or cage to keep the sapling protected for the first 3-4 years of it’s life. I do this with just about all of the trees I plant.

Planting depth, potting soils

No matter how you plan to sow Black Cherry seeds, you don’t need to overthink what soil to use or the depth. Any potting soil will work fine. The large seed size can push through any small twig or debris that may be present even in cheaper potting soils.

And for planting depth, again, to stress about it. Plant the seeds 1/4-3/8″ deep (6-9 mm). If you are unsure, it is usually safer to go on the more shallow side.

What about scarification or warm stratification?

Earlier in the article I mentioned that there are other germination methods that have given success to some. There are two methods I will describe – Sulfuric Acid scarification (which isn’t available to most backyard gardeners), and then a special protocol that involves warm stratification followed by cold stratification (which does work, and can be promising).

Sulfuric acid scarification

An old book, the Woody Seed Manual of the United States^[3] references that the highest germination rates can be obtained by soaking the Black Cherry seeds in sulfuric acid for 30 minutes before planting. While I don’t doubt their results, I still wouldn’t recommend this for backyard gardeners. That chemical isn’t something we typically have on the shelf, and even if we did, it can be pretty hazardous if it gets on you or is spilled. So, stick to cold stratification and you will be just fine.

Warm / cold stratification

So, I spoke quite a bit about cold stratification and why it is important to mimic nature. But, years ago when I first began researching how best to germinate this seed I read a paper that had great success with a period of warm stratification followed by cold stratification^[4]. So what did I do? Well, naturally I tried it as an experiment.

So, based on the protocol laid out in the paper, I conducted an experiment where I set up 8 pots with four seeds each. Four of the pots were subjected to two weeks warm stratification followed by 4 months (approximately) cold stratification. While the other four pots, with four seeds each had only cold stratification for approximately five months.

Treatment	Number of seeds	Germinated	Germination rate
Warm stratification / Cold stratification	16	11*	69%
Cold stratification	16	15	93%

So, technically my little experiment had a statistically significant finding (P-value = 0.04 2-Proportion test). And that cold-moist stratification alone was more effective than warm/cold stratification for Black Cherry seeds. But am I going to declare victory and that only cold-stratification is better? No, I’m not. There are many factors that go into setting up an experiment, and with my small(ish) sample sizes I don’t feel I have enough evidence (and no replication) to say it is better. I believe that if I repeated my experiment several times the results would likely converge.

But while this is fun to investigate and discuss, the main point is that you should not worry about warm stratification, but instead focus on getting your cherry seeds planted as early as you can. Why? Well, my seeds had about 5+ months of cold-stratification, and 93% germinated. There is no reason why you couldn’t recreate my results. Just gather fresh seed, and plant them as early as you can. Keep them moist, and don’t let them freeze.

When you think about it, there is some sound logic to the warm stratification followed by cold stratification. Hear me out – Black Cherry seeds begin to mature in August (zone 5/6/7). They are promptly swallowed by some bird, who flies away. The stomach acid in the bird scarifies the seed, which is then expelled out on the ground. If it maintains a moist environment through the remaining summer and fall, it will likely germinate. So how else could we state this scenario? Well, the has received scarification from the bird’s stomach acid, warm stratification from being expelled planted in late summer, and cold stratification in winter.

Don’t misunderstand me, I’m not advocating you to go eat cherry seeds in August and then plant them. But I’ve given you some good, actionable information in this article. Namely, cold stratify those seeds as soon as you can by winter sowing. Don’t let them freeze or dry out, and by late Spring you should have some trees. That’s it – that is what you should be doing. Good luck!

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