In my yard the darned things occur even in the dense shade of my shingle oak but are much more prevalent in full sun areas. They seem to be less of a problem in shade but even in that location are still a pesky weed. Poaky, a broadleaf weed killer like Weed B Gon gets the job done quicker. The fall, when they are newly germinated, is the best time for control .
hortster

Dandelions can grow in many habitats, sunny, shady, wet, dry, alkaline, acidic, lots of organic matter, no organic matter. Some are annuals and some are short lived perennials but they all grow from the prolific seeds that are produced. Some are fall germinating plants while others are spring germinating and others are summer germinating. Dandelions are a good food that contains many necessary nutrients that we need.
Rather then spray plant poisons around in an attempt to control these vigorous growers work at making the area they grow in inhospitable to them. If the seeds, and seedlings, are denied light they will not germinate and grow so a dense turf or planting bed is the best defense against them.

The common name 'Dandelion' refers to specifically to species of Taraxacum which are all either perennial (the majority) or biennial (a few) and have tap roots. There are many yellow flowered members of the Asteraceae which may well be erroneously called Dandelions, but no true Dandelions are annual. Although they will grow in a certain amount of shade they flourish best and flower most in the sun, so I think your problem will lessen as the area shades over. They have the ability to ripen seed even if pulled when still in flower. If the lawn grass is dense and healthy, although dandelions will manage to grow they can be kept from flowering by regular mowing.

They will grow anywhere and under any condition. Pull them up while they are young, you can kill them with boiling water, but it can take more than one application.

poaky, I share your pain. I have waited 20 years for the trees to do their shade trick, and it is working. When I bought this place (1987), it was a pasture without a tree, a corn field with no shade (maize field, if you read this from across the pond), and a set of barns and sheds with a Red Maple, 2 Black Walnuts, a cluster of Black Locust and a dying Cherry. I hate to mow grass. I also don't believe in raking leaves. What to do.....

What to do is plant trees whose leaves disappear near the house, and the Oaks, Chestnuts etc. farther away from habitation. Trident Maples, Japanese Maples, Dogwoods and Sourwood all have leaves that melt into the lawn. The shade from the trees really slows the growth of the grass, and most Dandelions have left the area.

I'm not fanatic about a lawn. I never fertilize, reluctantly mow, and never treat for weeds. But dandelions do get pulled from time to time. Ever pull one up and see the aphids clustered on the roots? These same aphids will attach to other roots too. Like on desirable plants.

If you ever get to York County,PA, passing through to Balt-Wash or stopping nearby, leave a note on this board. I'll give you directions and you can see what it looks like after 25 years. We've planted a few trees every single year, some years more, and after 25 years some parts are starting to resemble a forest. There's still grass to mow, but it grows slower, and the dandelions are more scattered.

Hey Dzitmoidonc, Kim Goldsmith or anyone reading this, it's been 6 years since I started this thread, I STILL get dandelions and they STILL grow in some places you'd think are too shady, BUT, no they are still showing up. I have relaxed my point of view about them a good bit since the beginning of my starting this thread. I just choose some places to keep free of weeds and some others, I just let nature do it's thing. My trees are MUCH larger also, I just mow over the leaves and let the leaves enrich the soil, some trees have a bunch of fall leaves under them and they just stay under the trees and rot, that will be good at fertilizing the soil like what happens in nature anyway.

I live in a very rural place though, so other may have to tidy up their yard or get fined, etc.