I guess it depends on what your time is worth. I did it for a few years and decided it was not worth it, considering the low cost of tulip bulbs. If you do try it you will find that many tulips create 'splits' with neither bulb large enough to bloom. Most tulips less than 12cm circumference will not bloom. When you sort out the splits and the undersized, the second year only about 30% will bloom again. With tulips going for about $25 a hundred or 25 cents apiece for 14cm sure to bloom bulbs, it was not worth it for me. Al

I only have 3-4 of these and grow mine in pots because I'm in zone 6. I've been lucky enough to have all of mine bloom in pots each of the last 3 years (I've had them 5), but not really sure what I might be doing right or not. Maybe a bit more sun and fert if they are not getting enough of either.....wish I could help more, but I'm just not enough of an expert on these or most any other plant for that matter :o) Dan

To be more specific and answer your question, after LAST frost I would put the pot outside. You are in zone 6 right? Keep in a sunny location, water well and after 1st frost follow previous advice. Here's what I include with bulbs I've given away or donated plant sales: Zantedeschia albomaculata: Calla Lily Form: Tender bulb. Exposure: Full Sun. Height: 24" (to 30" bloom). Spread: 18-24". Zone: 8-10. Flower Date: June-July. >Planting Reqs: Plant 4-8" deep and 18-24" apart when all danger of frost has passed (last week of May in ELong.). I plant those in back 4" deep and those in front 6-8" then cover all with 2" of compost/mulch. Fertilize using a 5-10-10 or 5-10-5 fertilizer. >Lifting Reqs: Lift the rhizomes after first frost, cut back stems, clean off excess soil, let dry out of the direct sun for a few days and then store in a dry location that remains between 50 and 60 degrees F. They can be divided before storage as long as the cut portions are allowed to dry. Doing so will prevent the open wounds from rotting. I use perlite in a PAPER bag. Check in late January. If rot is evident cut, scrape and clean off all rot. Coat cut surface liberally with powdered anti-fungal or cinnamon pushed firmly into flesh. Let dry and store. >Soil Reqs: Slightly acidic (6-6.5) well drained, humus enriched sandy loam. Adding mulch to the soil will help maintain a constant soil temperature. This will help keep the plant stress-free. Mulch will also improve the texture of the soil and help hold in valuable moisture. Calla lilies thrive in well-drained, loose soil. >Pruning: Remove spent flower stems to tidy up your plants and strengthen leaves and corm. >Note: Watch out for Japanese Beetles. Hope this helps. Evan

Sometimes when colored calla bulbs get too large, they don't flower as well. This fall, dig up the bulbs and separate them, and next year they should be blooming well. Also, don't plant the bulbs too close together. White Aethiopica do well in ponds or bogs, colored callas will rot and die. The growing conditions for white and colored varieties are completely different. The problem is, there is also a white flower that falls under the colored varieties... check the bulb for your growing conditions. Round flat bulbs should be watered and then allowed to dry a bit; while oblong, potato like bulbs can take the wet. Here is a link that might be useful: Calla Growing Guide