Yes, just cut the tape. Last year's radish seeds will likely sprout just fine. Your biggest issue with planting lettuces or radishes right now is the time of year. You don't indicate your zone, but if you live where it is currently moving into high summer, it is too late to plant these items. They are both cold season crops. They germinate better at cooler temps. If they do germinate, they are both likely to bolt (go to seed) very quickly. Radishes in my experience do not bulb up well in hot weather - they just go right to seed. Now, if you're further north or at a higher elevation or something like that, you might be fine.

Thanks couldn't reply back to your query but found out how to do it now. You are asking where I live. I live in Ontario, Canada north of Toronto. Everything here is slower to bloom. Whereas some roses are almost in flower in the US ours here are still in bud or just formed buds or have yet to develop any buds on them. Shot going out for this week. Sooooo may try next week and get a window sill container that would be wide enough to fit outside on my bedroom window ledge. Higher up than the living room. That way I can keep my eye on it to make sure nothing eats it before I do. :) Might have to pick up some more soil too. Bring my tape measure. as well.