Question about planting brussels sprouts

I am pretty much a novice gardener, but I am going to try Brussels sprouts. I did some research, and it says to start seeds five to six weeks prior to planting in the ground. (I'm in zone 5) The growing season is given as being about 5 months. Does that mean from germination to harvest, or from transplanting in the ground to harvest? I'm guessing germination to harvest? Last spring frost date in my area is around May 17th and first fall frost date is around October 5th. I'm pretty confused. It sounds like it might be a difficult plant to grow. I know it's really early, but I'm doing all my research now so I don't start my seeds too soon. If I'm reading it right, I should start the plants in mid-May and plant outdoors around the end of June for a mid to late October harvest?

I am in roughly the same zone as you here in Scotland UK, you are about right with your planting times, I start my seeds off indoors about April, 6 weeks later the plant-lets are ready to prick out into small pots, (seeds can be handled safely when they have grown 2 sets of leaves, one set is the seed sprout and the 2nd is the true plant leaves) once the pot is looking too small for the plant, it is time to plant out into the garden, this would be around June / July.
Brussels Sprouts like a well manured or composted earth, it has to be firm (so I lightly trample the earth) the firm soil helps keep the plants from rocking around as they become top heavy, I harvest the sprouts for Christmas dinner, they are still quite small and very taste, BUT, believe me,IF you can leave off harvesting till after there has been a frost for a good few days then this frost helps to sweeten and tenderise the sprouts, you can freeze them after blanching in boiling water and immediately cooling them. Hoe and keep weed free between rows and plants and if you live in a windy area, you may have to stake your plants, every year I am plagued with the dreaded white butterfly that lays eggs and the little caterpillars eat all the foliage, so now I cover all my sprouts / cabbages etc with sort garden fleece as this lets light in and water but keeps predators out. these are easy veg to grow and you should give them a try. good luck and hope you have a great crop. WeeNel.

Thank you WeeNel. That is extremely helpful!

Kathy

Kathy I live in Latrob Pa. 30 miles from you. I grow sprouts every year. They are tuff and withstand cold temp well. I remember one year they lasted all through the winter! Usually you will get the nice round sprouts in nov till jan depending on the variety. I usually buy the 90 day catskill which I bought tonight. ferry Morse 1.4 grams $1.59! If you want some free mixed sunflower seeds pm me! You can put them out early. I will start the this week in my solar geren house and throw a ew in one of my cold frames mixed with lettuce. The 90 day variety will be ready in sept and continue till jan. I love gardening!

Here, in zone 9, we should really plant in Fall - however the 6 paks I bought last year were available in Feb. Mar. By the time they got a toe hold we had our blazing hot weather. They did manage to stay alive and started to produce in Fall. They really took off in December. Then we had lots of rain and my DH let the horses 'run free' in the yard due to all the water in their corrals. Apparently horses find Brussels Sprouts and broccoli VERY yummy as they ate the stalks and all. All I can do is laugh, at this point.