Hello rbrt! This tulip should multiply and spread if it is planted in well drained soil, full sun, and hot and dry in the summertime. Many years ago I planted T. turkestanica which is related to biflora and they have made nice clumps of flowering plants.

When you want to create a groundcover effect it is best to plant at least 50 - 100 of these small bulbs in the same general area to get a groundcover appearance. It would take several years for the plants to multiply and spread.

A group of 5 or 6 of these tulips is super pretty, but it would be many years even under ideal conditions to get a solid covering of them unless I am completely wrong and this species takes over and dominates every area that it is planted! Tulip turkestanica multiplies well but not as crazy as T. Sylvestris - it spreads using underground stolons and can take over areas that are hot and dry during the summer.