Answer:
depends on your destination and the plant. plants are regulated by international phytosanitary regulations. the normal process is to obtain an import permit for the plant material from the country of destination prior to shipping or moving the plants. the conditions and regulations for the particular plant that you are wanting to transport will be stated on the permit.
it is not advisable to simply take plant material with you as some plants are banned in some countries besides the fact that some plants are strictly regulated and could earn you a spell in jail for even having them in your possession.