Help! New gardener in metro boston... too late to start?

Hi all. Im newbie all around... new to this site and gardening... my only experience has been herb gardening... which i am already doing... i would like to try to grow more flowers on my property (which has areas that offer a mix of anywhere from shade to sun... i believe im a 6a here in belmont, ma)
my question is... is it too late?
currently, there are several shrubs, roses, hostas, and hydrangea all doing well... tulips and muscari i planted did well and have now died back... id really love to fill in the spaces between and under these plants with a bit more color...
what is my best best for this point in the season? Is is too late to start seeds such as morning glory, cosmos, coneflowers, alyssum, canterbury bell, foxglove? if not, should i sow outdoors or start indoors first?
anyone have any suggestions for me? i would rather invest in plants that are lower maintanence and which will come back yearly... and could sooo use the help!!! Starting feels so over-whelming! I find myself wandering around confused at the garden center and continuously coming home empty handed! Help!

morning glories you can still start as i am still starting them. to get them to bloom faster once they have their true set of leaves the set after the first set you see then you can start giving them bloom booster by miracle grow once a week. as your season is shorter then ours.

most of the time these cosmos, coneflowers, alyssum, canterbury bell are annuals in most places. if mulched enough coneflowers, alyssum, canterbury bell and foxgloves as they are perennials might come back. they do self seed each year also. you do have time to start annuals. june july august you should still have time for those to bloom also. perennials you can buy and plant now with no trouble they have time enough to set roots in a couple months.

sowing indoors is how i do it then i can plant them where i want. place in sunny window with bottom heat if possible.

annuals are great because you can pick flowers you like and next season may see something different to put in that spot and have no worries. if you dont want to be buying all the time then perennials are the way to go. but annuals give you color right now till you find what you really want to go with.

if you want them to come back make sure they say perennial if you didnt know. that means they come back annual is one year only. my hubby gets them confused all the time.

remeber not everything lowes and home depot and walmart sell are for your area. they sell things for money. they dont always sell stuff just for your area. a nursery is a better place to go and find one you are comfortable with.

a good nursery is where the people want to help and dont ignore you. im on a first name basis with my nursery. so good luck and hope this helped

ps you can ask questions here someone will answer all the time

You can never go wrong with daylilies!

so true