How to Grow a Conifer From a Pine Cone
- Look for ripened pine or other cones beginning in late summer. The seeds form between the overlapping scales and are released as the cone dries out and shrinks. Put the cones, separated by variety, onto a screen in a warm, airy place, to dry. As they shrink, they will release their seeds onto the screen.
Stratify the seeds by placing them into the refrigerator for four to six weeks. Stratification will help ensure better germination; seeds of some varieties of conifers will not germinate without this cold treatment. Soak the seeds overnight and then drain them. Place them in moistened vermiculite or peat moss in a glass jar. Place the jar in the refrigerator for the required length of time. - Fill individual 4-inch pots with a soilless growing medium. Mix 1 part peat moss with 1 part vermiculite or perlite for starting conifer seeds. Sow a half dozen seeds in each pot, burying the seeds about 1/2 inch deep.
Keep the pots in a protected location outdoors, away from intense sunlight and high winds. A cold frame fitted with shade cloth is ideal.
Water the seedlings as needed to keep the growing medium moist; if allowed to dry out, the seeds will return to a dormant state and not germinate.
Apply 4 to 6 inches of protective mulch after the first killing frost in autumn. Close the cover of the cold frame for the winter months, leaving the shade cloth in place. - Seeds planted in autumn after stratification can be expected to germinate the following spring. Prop open the top of the cold frame and remove the mulch in very early spring, as soon as the ground begins to thaw.
Thin the seedlings to the strongest one in each pot when they germinate later in spring. Continue providing water as needed to keep the pots from drying out. Move the plants out of the cold frame and into a protected location in full sun, but protected from the late afternoon sun, when daytime temperatures rise to 40-degree F temperatures.
Repot into 8- to 10-inch individual pots when the seedlings outgrow their nursery pots, using a mixture of 1/2 peat moss and 1/2 indoor potting soil. Move the seedlings back into the cold frame for winter, following the same procedure as before. - Transplant the seedlings into a nursery garden bed when the ground warms up in mid to late spring of the seedlings' second year. Space them about 1 foot apart in rows 2 feet apart.
Feed the seedlings a diluted mixture of fertilizer specially formulated for acid-loving plants and labeled for evergreens, blueberries or azaleas. Continue watering as needed to keep the growing bed consistently moist. Mulch the soil to conserve moisture and stop the growth of weeds.
Transplant seedlings into their final location in your landscape in the spring of their third year.
