How To Grow Eastern Red Cedar Trees From Seed

I’m going to get straight to the point here. I know how to grow Eastern Red Cedar Trees from seed, and will show you how. After several years of trying with limited success, I developed a method of scarification and stratification that produced a 40% germination rate, which isn’t bad for a difficult seed. It sounds complicated, but I assure you it is not and the materials are readily available. Anyway, read on to see exactly what to do to grow your own Cedar trees from seed.

A couple important pieces of information up front before we get started. First, seed from Eastern Red Cedar trees doesn’t store well. So we will want to be working with fresh seed if possible. Second, Eastern Red Cedar trees have a hard outer shell that will prevent germination (scarification)^[1], and it also has a warm-moist stratification period of 30-45 days, and cold-moist stratification requirement of 60 days^[2][3][4]. So our process will be more involved than just burying some seed. And 3rd, since our stratification periods are pretty long, it is a good idea to start the overall process by January 1st.

If you’ve tried to do so in the past and been frustrated or unsuccessful, well I understand. I can also say that the problem was most likely in the ‘preparation’ of the seed. But, without further ado, below is exactly what you need to gather and germinate Eastern Red Cedar seed.

Background / Overview

Since common names can often be confusing, let me also state up front that the Cedar tree I’m referring to in this article is Juniperus virginiana, which is most commonly referred to as the Eastern Red Cedar. This is an evergreen that will keep it’s leaves all winter (they sort of look like needles). And there are male and female trees – the females produce berries that turn blue in autumn/winter when ripe. If you want more on the identification of this tree, see my guide here.

How nature germinates Eastern Red Cedar trees

Ok, so how does an Eastern Red Cedar seed germinate in nature? Well, what usually happens is a bird will eat a ripe berry from a tree. Then, it will fly off and find somewhere to perch (usually a fence post) and digest it (within 15 minutes)^[5], and then poop it out. The digestive juices, in the birds stomach, which are highly acidic, softens the coat (scarification).

The berries typically ripen in September/October, and thus the seed will be in contact with the soil in late Summer for a period of time (warm stratification), followed by sitting in the soil through winter until Spring(cold-moist stratification). Come Spring, as the sun begins warming the soil, the seed will germinate and voila! A new Cedar tree is born.

In a nutshell, we are going to do this same process by gathering ripe seed, scarifying it with a citric acid solution (it’s easy to make), giving it a period of warm stratification, and finally winter sowing the seed (cold-moist stratification). The combined stratification time is roughly 3 months. For timing, assuming we wanted our seed to germinate by April 1st, we would need to begin the scarification process by January 1st.

Saving Cedar Seeds

You need to only take berries that are ripe/blue. Anything that is green or off-color should be left on the tree.

To gather the seed, simply strip some berries off the tree, and you can . If you are trying to collect a lot of berries, you can lay down a tarp or blanket and shake the tree. But, expect a 30% germination rate, so gather about three times as many berries as you want seeds.

Any berries you collect should be stored in the refrigerator in a sealed container or bag until you are ready to plant. If you are ready to get started on this process, proceed to the next section. But if you need to store them for a week, then just make sure the berries are dry on the outside by letting them airdry for a few hours, and them store them in the fridge, sealed up.

Otherwise, go ahead and squeeze out the seed from the berries. Each berry will contain between one to four tiny seeds.

Scarification of Eastern Red Cedar seeds

To scarify Eastern Red Cedar seed, the best way is to dilute some citric acid in water. You should plan on doing this process by January 1, assuming you live in zone 6 or 7. This method works well, and the citric acid is readily available at grocery or hardware stores (go to the canning section), or from amazon. You don’t need much for this job, so unless you plan on restoring some old tools, you can just buy the smallest amount.

The recipe I’m going to give you makes one liter of solution (1/4 gallon) which is way more than you need for a handful of seeds. But most people don’t have measuring spoons less than 1/8 teaspoon, so I am giving it to you in that amount. But here is the recipe: dilute 1/8 teaspoon of citric acid powder into 4 cups of water^[6] and mix until the acid powder is dissolved.

Pour some of this into a coffee cup or glass, and then place you see in it to soak for 1-2 days.

Warm stratification

After two days in the citric-acid solution, remove the seed and rinse off (a fine kitchen strainer helps) in tap water. Then, we are going to warm stratify the seed in a paper towel. To do this, take a paper towel and get it moist in tap water (make sure your hands are clean). Get it wet enough so that when you squeeze the towel only a few drops of water squeeze out.

Then, on a clean plate, lay out the moist towel and fold it in half two times. Then, place your seeds on half of it, and fold over so that the seeds are essentially sandwiched between four layers of moist paper towel.

Place this paper towel in a zip lock bag, sealed, in a warm location (70-85F) for 4 weeks. I used the top of my water heater, which is generally about 80F.

You will want to check the seeds weekly by making sure the towel stays moist, and that no mold is on the towel. If you see mold, don’t fret. Just remove the seeds, sterilize them in a 10% bleach solution for 2 minutes. Then rinse, and place them in a new paper towel/bag like before, and continue the warm stratification.

Cold Stratification / Winter Sowing

Once the warm stratification is complete, we need to cold-moist stratify the seed. Now, you could just toss the Ziplock bag into the refrigerator for two months, but you will still have the risk of mold on the paper towel. So to avoid this risk, we can winter sow the seed to achieve the cold-moist stratification. I have a very detailed guide and video on winter sowing here, but I’ll briefly summarize the process below.

I like to use milk jugs for most of my winter sowing. To do so, I wash and rinse an empty milk jug. Next I add drain holes using a knife or screwdriver. Then, I cut a hinge at the the handle using a pocket knife. I then fill the container with very moist potting soil. Now I am ready to plant the seed.

The planting depth for Eastern Red Cedar seed is fairly shallow at 1/8″-1/4″ deep (3-6 mm). So, take your winter sowing container and tamp the soil firm. Then scatter your seed on top, and cover it with 1/8-1/4″ of moist potting soil.

Use duct tape to seal up the milk jug, and place the container in an unheated garage or shed, as we don’t want the seed to freeze if we can avoid it. Once Spring arrives, we can move the jug to a location that receives morning sun and afternoon shade.

Germination

You can expect the seedlings to germinate in Spring. I usually notice the first signs of germination in April or May. You can keep the baby trees in the jug, sealed up as long as the daytime temperatures remain relatively cool (<70F). Once daytime high temperatures are forecasted to exceed 70F, you should remove the duct tape and open up the jug.

Establishment

After about 3-4 weeks, there will be 2-3 sets of true leaves. At this time, carefully separate the seedlings and transplant them to larger pots (6″ deep, minimum). We will want to continue to grow the trees for several months so they can develop a strong root system. For some tips, see my detailed guide on separating seedlings.

Continue to care for the trees all summer in pots, keeping them in full sun and watering them daily. You will want to grow them for about three months and think about transplanting to their final location in September or October. You can theoretically plant them in their final location right up until the ground freezes, but giving them at least several weeks for their roots to attach to the soil is a good practice.

If you don’t want to plant them, but over winter them until the following year, you can do so, but do not let the roots freeze. It would be best to keep the pot indoors where it will receive sunlight.

How effective is citric acid scarification?

So, I mentioned in the beginning of this article that I had tried several times to grow this tree. I have done some experimentation that I previously wrote about, trying different forms of scarification. In all, I tried sandpaper, warm-water soak, and just cold-stratification….and by far, the most successful method was the citric acid soaking that I described here followed by warm and cold stratification (winter sowing).

Treatment	# Germinated	GR%
TREATMENT 1 – Hot Water Soak / Warm Strat / Winter Sow	2	10%
TREATMENT 2 – Citric Acid / Warm Strat. / Winter Sow	8	40%
TREATMETN 3 – Mech. Scarification / Winter Sow	1	5%

Now I am a big fan of using sandpaper to scarify seeds when possible, as you are in full control and can see the results instantly. But these seeds are so tiny that you have to gently rub them between two sheets of paper, and I found it too easy to actually over-scarify or crush the seed. Also, I should note that in other years I had tried simply planting the seeds and leaving them outside over winter, so cold-stratification only. I never had anything germinate using that method.

Other thoughts on scarification

I must say, that I generally shy away from attempting any kind of citric acid soaking for starting seeds. It is just one extra step, and I don’t like doing the math to figure out the % acid solution I am supposed to do. One year I went overboard, applying acid treatments to numerous species. And although it is annoying to do (and even more annoying to document it all) I did have great results. Species that are listed as difficult to germinate…I had tons of germination. Elderberry, Buttonbush, raspberry, and winterberry….I had some success with all of them, and they generally have a reputation of being difficult to germinate. So, I guess sometimes it is necessary to go the extra mile and pull down my 10 lb bag of citric acid from the shelf. Till next time.

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