[wpears]

If the DNA in a seed is still in good enough shape to support blooming after being frozen 30,000 years, perhaps a seed frozen in a meteorite [1] could also survive long enough to be spread between solar systems.

[1] maybe after glancing off a planet or created by the collision of two large objects

[ASalazarMX]

I'm no expert, but wouldn't said seed first be baked by the heat of an impact strong enough to launch a chunk of planet to space?

[pvaldes]

Could survive long enough to be toasted when the meteorite finally falls to the promised land planet, in form of fireball.

[dgudkov]

Inner ice of sufficiently large comets can survive atmospheric entry.

[spacecop]

Ah, I see. Thanks!