How to Grow a Sycamore Tree from Seeds

Looking up the greenish trunk of a sycamore.

With careful planning and attention, you can grow a sycamore tree from sycamore seeds. Municipalities across the country are encouraging people to plant native trees, and the fast growing and dramatic sycamore is an excellent choice.

TIP: Our expert gardening advisor, Susan Patterson adds, "Sycamore trees will grow in USDA growing zones 5-9."

Step 1 - Obtain Sycamore Seeds

You can get sycamore seeds from a garden center or nursery, or ask someone you know with a healthy, mature sycamore tree to save some sycamore fruit pods for you in the autumn. Dry out the fruit completely, and then cool it for 12 weeks to 40 degrees F (4 degrees C) or colder.

Step 2 - Revive the Seeds and Extract Them from the Fruit

Remove the fruit containing the seeds from its cold storage and allow it to come to room temperature slowly. Crack open the dried fruit pod with a nutcracker and remove the seeds, called achenes. Clean off the dust and fine hairlike fibers on the seeds. Wear gloves and a face mask to brush off the dust, working in a well-ventilated area. Rub the seeds in a piece of hardware cloth that has a medium wire weave (10 wires per inch) to scrape off the dust and hairs more easily.

Step 3 - Prepare the Potting Medium

Prepare planting trays to hold about 20 seeds for germination. Sycamore thrives in strongly acidic soil, with pH ranging from 4.5 to 5.0. They germinate quickly in moist but not drippy soil, with a high percentage of peat moss and other organic material.

Step 4 - Pretest the Seeds for Fertility

Place several sycamore seeds in wet sand or on damp blotting paper for 14 days. Alternate day and night lighting conditions and temperatures for the seeds from room temperature at night up to 85 degrees F (30 C) in daylight. A large proportion of the fertile seeds will begin to germinate under these conditions. Choose several and put them in the prepared potting soil.

Step 5 - Plant the Seeds to Continue Germination

Press the seeds gently into the prepared seed trays, no more than 1/8 inch deep. Keep the seeds 6 to 8 inches apart in the trays. Cover the sycamore seeds with a light mulch of leaf mold and peat moss.

Step 6 - Maintain the Seedlings

Water the sycamore seeds regularly and prevent soil from drying out. Keep the seed trays out of direct light for 30 days. When the seedlings reach a height of 4 inches, move them into individual pots, with sand and fine gravel added at the bottom to promote drainage.

Step 7 - Plant the Sycamore Seedlings

When the sycamore seedlings have grown to 1 foot tall, they are ready for planting in the yard. Check for a well-defined root system and several twigs with maturing leaf buds on the seedlings you want to plant. Plant them 10 to 12 feet apart in the yard, as the rapid-growing sycamore's roots will spread dramatically in their first season.

TIP: Susan notes, "Sycamore trees are fast growing and reach a mature height of 75 feet."