Tree seeds germinate at home once the treatment listed for the species breaks their dormancy, usually a water soak, stratification in moist cold or warmth, or both, and they are then sown in a moist, well drained mix kept warm and dim. Germination can take a few days or several months, so the mix stays damp under a vented plastic cover until sprouts appear.

Why won't many tree seeds sprout as soon as they are planted?

Because many are dormant when they ripen. A hard seed coat can block water, chemical inhibitors can hold the embryo back until winter passes, and some embryos are still immature, so whichever barrier a species has must be cleared before sowing.

What is scarification, and how is a hard seed coat softened?

Scarification softens a hard seed coat so water can reach the embryo, usually with a 6 to 24 hour soak in room temperature water; some species call for hot water, and others for filing or sanding the coat without touching the embryo.

Steeping Cedar of Lebanon Seeds in water for 24 hours is their only treatment, since they need no stratification before sowing about 3/4 inch deep.

How deep should tree seeds be sown to germinate?

Shallow, in trays or small pots of a well drained mix such as peat moss and vermiculite. Seeds over about 1/3 inch are pressed halfway in, while smaller ones are sprinkled on top and covered with sand as deep as the seed is thick, since planting too deep can delay germination.

Where a species needs light to sprout, as Paperbark Birch Seeds do, the seed is scattered on the surface and kept moist rather than covered.

Frequently Asked Questions

What do the start instructions on a seed listing mean?

They give the steps in order: scarification, stratification, germination depth, and any other notes. A line reading "None required" means that step is skipped.

Should the soaking water be hot?

Only when the listing calls for it. Most seeds soak in room temperature water.

Is acid scarification needed at home?

Usually not. TreeHelp's guidance treats it as rarely needed for home growing and calls for goggles and protective clothing whenever acid is used.

Why might some seeds in a batch take years to sprout?

Because dormancy breaks unevenly. Some tree seeds germinate over two or three years, so a container that shows nothing the first spring is kept moist rather than discarded.