Most folks don't bother with shrubs from seed because it takes such a long time from germination to a flowering size. They often require some specialized attention with respect to germination requirements or stratification that many growers are disinclined to bother with. You can find seeds for various shrubs online but they are not often carried by the larger commercial seed vendors that supply annual, perennial and vegetable seeds.....it is a rather specialized market.

Vegetative propagation is much faster and can provide significantly sized plants much more rapidly so most growers utilize cuttings, layering or grafting to propagate their plants. And some plants will only come true to their parents if propagated by vegetative means -- seed generated offspring are not always that desirable.

Here is a link that might be useful: an interesting link on growing shrubs from seed

Thanks

That means I don't need to bother about growing shrubs from seeds but it seems propogation is the way to multiply plants which will be economical. I will search this forum for propogation ideas but if anyone has found them please post a link.

jaggudada - 'Propagation' is any means of producing new plants. So seeds are a means of propagation too. Propagation techniques other than seeds are 'vegetative' propagation. As gardengal says, this includes cuttings, layering and grafting.

It might be best to find the names of some shrubs you want to grow and then research propagation methods for each one. Shrubs differ in their ease of propagation and their requirements.