Fennel develops a tap root pretty fast so I would not bother starting indoors at all. However, since you've done it, I would harden them off and plant outside asap. Likewise the dill. A light frost won't bother either if they're hardened off. I would sow both straight into the ground outside in future. Fennel is a perennial which also self sows, so you shouldn't need to sow it again. One plant would probably provide all your fennel needs for leaf and seed, unless you are addicted to the stuff. Disclaimer .... you don't say where you are located. Fennel may not be winter hardy if you are in a cold area.

Thank you @floral_uk z.8/9 SW UK. I will start hardening them off from today. It will take 7 - 10 days and by then the weather will be warmer. Good to know dill and fennel can take slight cold. I do like fresh herbs.....but I am growing these to bring in pollinators an especially the swallowtail butterflies. I see other gardeners grow Bronze Fennel as a perennial, at least for a few years. I am trying that.

Are those bronze fennel seedlings? Usually the colour is visible from their babyhood. Maybe it's not showing in the photos?

Ha ha. been there before (and now) and continuously plant my seeds later then the last year. I've become tired of big plants needing to up pot them but did it again with brussel sprouts this year taking up to much space under the lights.

Your dill is hardy down to 25 degrees so a couple weeks of hardening off and you'll be fine to plant. The Fennel is hardy to even lower temps and could go into the ground in a week with your last frost date on April 27th. I wouldn't up pot either and could do more damage to the roots than could regrow before sticking into the ground.

I started my sprouts in mid February in 16 oz cups just so I wouldn't need to up pot them, and plan to plant them about 6 weeks before my last frost but the snow needs to melt first.

I find dill and fennel grow just fine direct sown outdoors, and as mentioned already, you only have to plant them once because they will self seed and/or you collect seed. Most of the plants in that umbellifer family (carrots, parsley, dill, coriander, fennel, etc) tend to do best direct seeded.

I live in a place with a cold winter climate (eg 2 months of pond hockey in the neighborhood) and fennel does overwinter. It gets huge and shades out nearby plants so I wouldn't want more than one.

For dill, I have found sometimes it doesn't start in great numbers from seed. Maybe some varieties prefer to go through some cold damp time in the ground before the weather warms up and they sprout. Anyway once they do grow, I let them self seed around the garden. Dill doesn't get huge, and dies after setting seed.

I planted several pots with several dill seeds each - quite awhile ago. I discovered that one - 1 - seed actually spouted. I guess I'd better treasure it.