Spider plant, It is best to propagate in soil. If propagated in water, roots will form within seven to 10 days. Using the soil method may take a little longer, but the roots will be stronger.. *Fill a pot (with drainage holes) with a well-draining soilless mix. Place the baby plant with soil mix. Leave it for 2 weeks then cut off from the mother plant. Water well and place in a bright location away from direct sunlight. | Growwithnith