I'd say they can stay inside 3 weeks, 4 at the max. Cucurbits don't really like being transplanted but if it's necessary then it needs to be done while the plants are young. The larger the pot the more time you might have before they must be planted in the garden. Rodney

Ideally, I like a 6-8" transplant, minimum. 5-6" is usually "good enough", though - if well-grown and healthy. Much smaller than that, and I'm almost tempted to leave it in the pot for a couple more days to get bigger before planting out - tough call. For instance/example, if it was 3/12 and I was ready to start planting, I would start with the largest seedlings first. After all, you don't have to plant them all the same day. So, you might as well go ahead and get the decent sized ones in as soon as possible. Then I might wait a couple or three more days on 3-4" seedlings, etc. Much past the 18th, from what I recall living in the metroplex, it starts to get iffy. Much the same here; it's not too different. And, I think we are in for another spring (hope I'm wrong :-)). One yr I got a late planting start (3/23) and got some decent fruit, but overall production was on the low side. Think that was '04. Getting them outside in general - if you still have seedlings under lights, you should be able to move them outside during the day now to *gradually* harden off and start catching sun. Just be careful at night - put in garage or bring in if cold, etc. The longer you leave plants under lights, the longer it takes to harden them off. Suggestion: start seeds earlier next year. What you've described should -just- work - assuming the seedlings are well-grown from this point on. The smaller ones might be a bit of a stretch. Also, be careful of high wind when they go outside, it can damage your seedlings every bit as badly as just shoving them outside all day in full sun the first few days. Basil - I am not generally in a rush to get it planted out in the garden since it grows like a weed once it warms up. I might put transplants in late March. I haven't even started mine yet, but need to do so soon (procrastinating). But any basil seedlings can go outside during the days now just like the tomato seedlings. Would also need to be gradually exposed/hardened off, too.

Jon Im in 6b and mine have been outside since the end of march. Looking back at the weather for Long Island it looks like you could have brought yours out early to mid May and been just fine. April had a few frosted nights but overall probably just fine for taking yours out during the day. Thats the other thing. if you have warm days during winter, fall or early spring say 60F+ you can get away with taking them out for awhile and then back in for the cold nights. I do this all the time. The sun could still burn them but since the angle is low its not as risky.

beesneeds I am in same zone as you, and keep hardy succulents outdoors. They do well (as you can see in photos I posted in a thread linked to above). Sempervivums are hardy to z4 and many to z3. There are some - like Oddity - that I have seen rated z6 but also lower. I kept few divisios indoors (unheated breezway, where temps dip to about 20*F) and original plant outdoors first winter (it was colder than last), and they all survived. They take couple of weeks longer to recover from winter, but they live. I kept offsets of other semps outdoors too, and they are just fine. Others - like many hardy sedums - I never protected in any way. They are in middle of the yard, exposed to any snow, sleet, freezing and so on. They are very hardy, and grow happily year after year. No need to keep them indoors - that space is always in demand for tender plants :) Of course, if you have space - why not. But hardy succulents should have some months of cold temperatures - they are hardy perennials, after all.