Tree seeds for hobby gardeners and professionals alike. If you wish to try growing these seeds please remember they are slow growing and require patience. Seeds are best planted in a coldframe in the fall for spring germination, however,early spring sowings indoors are quite successful. Indoor sowing tip: sow seed in trays, moisten then place the planting tray outdoors in the cold for 3 weeks. Even freezing temperatures will not hurt the seed. Bring back in and place under growing lights. This simulates a natural period of stratification and will improve seed germination.