Have you noticed the graceful beauty of magnolia trees? Their fragrant pink or white blossoms are one of the most delightful signs of spring. In summer, fruits form, each resembling a narrow pinecone adorned with gorgeous bright red berries. In fall, these berries split open to reveal a black, flat, bean-like seed, just one per berry. Birds or mice eat them, spreading the seed naturally to another location.
The seeds lay dormant all winter or are collected by a curious gardener like yourself. If luck is on their side in the wild, they will germinate in the spring and grow into a beautiful tree to live many decades. We can mimic what happens in nature by providing magnolia seeds with cold stratification and sowing them by hand the following spring.
Propagating a new magnolia from seed takes many years, but it can be a very rewarding and cheap way to propagate this classic ornamental tree. Let’s discuss how to do it yourself in eight steps.
Verify Tree Is A Standard Species, Not A Hybrid
First, to propagate magnolia trees from seeds, ensure the tree is not a sterile hybrid.
Magnolia seeds are not viable once they have dried out, so you can’t simply purchase them from your local garden store or favorite seed company. Taking cuttings and grafting are more popular propagation options. Finding fresh seeds is required to start a new tree from seed.
First, locate a tree to harvest from and confirm it is a standard species. This is important because if your seeds came from a hybrid, they won’t grow the same tree. It will be sterile or unable to produce seeds and may not resemble the parent tree. Unfortunately, it may take a decade or more to realize this unfortunate mistake, so it’s best to investigate from the start.
Harvest Fresh Berries
Magnolia trees bear cone-shaped fruits that fill with red berries in fall.
The cone-shaped fruits magnolia trees produce are made up of many smaller follicles. Each one is filled with red berries in the fall. You need to harvest seeds that are as fresh as possible, so once you locate the fruiting tree, pluck a mature cone from it. Remove the berries from the follicles by gently shaking them.
Remove the Outer Layer and Clean the Seeds
Clean magnolia seeds by removing their waxy outer layer, soaking, draining, and washing to remove the oily film.
Once you have the berries, remove the waxy outer layer and clean the seeds.
- Soak the berries in warm water overnight or for several days to soften the red outer shell. Then, you should be able to remove it, revealing the seeds.
- Good seeds will sink, so discard any floaters before draining the water.
- Drain water.
- Wash the seeds with soapy water made with an organic dish detergent to remove the oily film that surrounds the seeds. This film prevents the seed from drying out once outside in nature and needs to be removed before the next step.
Cold Stratification
Imitate winter conditions with cold stratification for magnolia seeds by storing them inside a refrigerator.
Refrigeration mimics what the seeds might go through during the winter after being discarded in bird or mouse droppings. They simply sit dormantly, waiting patiently for spring. This period of cold exposure is called cold stratification. Studies show cold stratification positively affects seed germination, shoot height, and root length.
Place your seeds in a wet paper towel or tucked into moist compost or seed-starting soil, and move them to a clean, air-tight bag or container. Store them in your refrigerator for the winter, ensuring they do not dry out. Remember, the seeds will not be viable if they dry out.
Sow Seeds
When the risk of frost has passed and the ground has begun to thaw, remove your seeds from the refrigerator. If you grow in a zone that doesn’t receive frost, you may remove them as early as mid-January. Go through and remove any dried, rotten, or damaged ones.
You can sow the seeds in one of two ways:
Seeding in Containers
Fill pots with seed-starting mix, sow seeds, water, and expect sprouting in 4-6 weeks.
Prepare pots or seed trays by filling them with a seed-starting mix. Sow seeds ¼ – ½ inch deep. Cover and water them well. Place in a warm area or atop a heat mat set to 70° and ensure the soil does not dry out. You should notice sprouting in 4-6 weeks.
Direct Sowing
Select a permanent location, sow magnolia seeds, add compost, fertilizer, and water, and anticipate germination in 4-6 weeks.
Choose your location carefully for the long term. Although magnolia trees can be transplanted, it’s not ideal. Sow seeds ¼ – ½ inch deep and cover with soil, adding a little compost and slow-release general fertilizer. Water well and mulch. Depending on your growing zone, seeds should germinate in 4-6 weeks.
If you don’t see germination, your seeds may have dried out, frozen, or become a snack for a hungry chipmunk, mouse, or squirrel.
Transplant
Grow magnolia seedlings in larger containers and transplant them in spring for optimal growth.
It’s best to transplant magnolia seedlings in the spring of the following year. These baby trees are moderately quick to grow and can sometimes be transplanted from their containers in the fall of the year they were sown. However, they have large surface roots that may be damaged during a fall transplant. Plus, you don’t want to encourage new growth before winter. In most climates, waiting until the following spring to transplant is best, especially when winters are harsh.
Step seedlings up into a larger container as needed and continue to keep them well-watered. Store them in a semi-heated garage, basement, utility room, or greenhouse for the winter months. A riskier option is to heavily mulch them and keep them in a cold frame for the winter.
When it’s time to transplant, your plant should be several feet tall with one central leader and feature a strong, healthy root system. Select a location that receives full sun with loose, well-draining soil.
When transplanting:
- Dig a hole about as deep as your seedling root ball.
- Place your magnolia seedling in the hole with the crown of the plant, even with the soil line.
- Backfill with native soil and gently tamp it down around your seedling.
- Sprinkle in a slow-release granular fertilizer and mix it into the soil.
- Water well.
- Mulch with woodchips, compost, or organic straw.
Mulch
Mulch direct-sown seeds with compost or straw and shield seedlings from direct sunlight.
Seeds directly sown in containers can be covered with vermiculite to help the soil retain moisture, whereas seeds directly sown outdoors should be mulched with compost or straw.
This will help keep moisture during germination and protect it from any spring fluctuations in temperature. During the seedlings’ first year of life, shield them from harsh, direct sunlight with shade cloth.
As your seedlings grow, continue to add mulch each season around the base, keeping it directly off the trunk. Do this in spring or fall during your annual cleanup after weeding, removing fallen twigs and leaves, and fertilizing.
Wait For Blooming and Maturity
Magnolia trees grown from seed typically bloom in 10-15 years.
Magnolia trees that start from seed will bloom in about ten years, but some species may take up to 15 years. Trees grown outside their preferred zones may never successfully bloom, so choose the right one for your zone.
Native to the southeastern United States, they can be grown in zones 2-10 but perform best where winters remain mild, thriving in zones 7-10. Some species can take up to 20 years to fully mature and grow to 70 feet tall, so selecting the right location is key.
What About Winter Sowing?
Winter sowing magnolia seeds outdoors mimics natural conditions, often proving more effective for germination.
Many growers have turned to winter sowing magnolia seeds, finding that keeping seeds inside the refrigerator for a few months couldn’t fool the seeds. It seems the constant relative humidity and temperature of the refrigerator simply don’t mimic nature enough to signal the seeds to wake up and germinate in spring.
If you try starting magnolia trees from seed after cold stratification and have a similar experience, try winter sowing them. Follow steps 1-3, but rather than storing seeds in the refrigerator, sow them in containers and store them outside for the winter. This allows them to experience what’s happening in nature, including sunlight, rain, snow, wind, and fluctuating temperatures.
If you have more than just a few seeds to experiment with, try cold stratifying some seeds indoors while others can fend for themselves by winter sowing and see which method works better for you. If you end up with extra magnolia tree seedlings, share them with a gardening friend or sell them in spring.
Frequently Asked Questions
Seeds should germinate in 4-6 weeks under ideal conditions.
Although not ideal, seeds can be held in a controlled environment between 32-40° if you must prolong the storage for a few more months. It is very important that the seeds or storage medium don’t dry out. If they lose too much moisture, the seeds will not be viable.
Possible reasons for a magnolia that isn’t blooming include: low soil fertility, growing outside the species’ preferred zone, and the tree being too young. Most magnolias don’t begin blooming until they reach about 10 years of age.
Final Thoughts
Magnolia trees add beauty, color, and enchanting interest to landscapes all across the globe but are an especially popular sight to see along the streets of the Southern United States. While starting them from seed takes extra time, patience, and effort, the reward is your own magnolia tree, and you won’t be disappointed.
