Dandelion leaves can be dried at any age, but only for short term use, as I believe they lose their nutritive and medicinal value fairly quickly upon drying.

You can also create a leaf tincture, or a leaf and flower tincture, by filling a clean bottle with leaves and pouring over them a good vinegar, vodka or brandy. Cap the bottle (or cork if using vinegar) and leave to develop for about 6 weeks, after which some tincture can be taken as tonic, or added to soups, salad dressings or other recipes.

If you have a large stand, in the fall you could dig the roots of several plants, and dry those. Dried roots are a good medicinal, and can be roasted for a coffee additive or substitute. I have never had enough roots to do this, but it sounds wonderful.

If your dandelions need to be moved, you could consider transplanting them into flower beds or large pots where they will be safe from lawnmowers and pesticides. Then you can enjoy them fresh.
Jeanine

Thanks. I have boughten dried dandelion leaves from the Health Food Store so i assume that they r not all that good seeing as how i don't know how long they have been there and even how long it has been since they were picked.

Thanks for the info on the leaf tincture. I will try that.

If you don't mind using the root (it's got lots of nutrients too, the whole plant does), you can dry it. It's also a great substitute for coffee, I roast the roots in the oven on a cookie sheet until they are brittle. Not sure if this destroys any nutrients or not though.