Make sure you get the right "dandelion" as there are a few that look like it,but can cause serious health problems if eaten.

Dandelion leaves can become tough and bitter when old. To keep them sweeter for salads and medicinal teas, remove the older leaves, then cover the plants with a box to keep out the light for several days before using the fresh young leaves.

Sow seeds at 20C, about 2mm deep, but germination can be slow, usually taking 10 days. It prefers a rich soil and full sun, and when grown in pots it needs frequent watering, and excellent drainage. It self-seeds readily and can become a nuisance weed. To prevent this, remove flowerheads as they appear. If cultivating dandelions, plant them in a raised bed with plenty of woodchips or sawdust added to the soil, to make it easier to dig out the roots.

Dandelion is a diuretic which helps rid the body of toxins. It is used to treat high blood pressure, gallstones, acne, eczema, psoriasis, osteoarthritis and gout. Good for the liver. Contains calcium, phosphorus, iron, potassium, Vitamins A and C and magnesium, and is a better source of carotenoids than carrots.

Warning: May cause bed wetting in children from excessive handling. Use with caution, and under medicinal supervision, if suffering from gallstones, stomach ulder or gastritis. The milky latex in the stem and leaves of fresh dandelion may cause an allergic rash in some individuals.

Like many herbs (including spinach, lettuce, sorrel, turnip greens etc) used as 'greens', the leaves contain oxalic acid which can be harmful if used to excess, and which gives the characteristic bitter taste. One way of reducing the amount of oxalic acid is to boil the leaves in several changes of water. This process will of course leach out many of the medicinal and nutritious qualities of the leaves as well. The solution is to limit the amounts used. I have no information on any recommended 'dosage' rates when applied to dandelion leaves used as food, but I can't imagine you'd be eating vast amounts of them! Best to say 'use in moderation'. The same applies to dandelion roots and flowers, which are also edible. For the sake of argument, and picking an arbitrary figure out of the hat, let's say, eat a dandelion salad once a week or so. Certainly, when used medicinally, it should be used for no longer than a few days (for instance, if undergoing a detox).

Thanks for the reminder, Kevin. There certainly are several dandelion lookalikes.

Daisyduckworth: I think that's the 'message' behind the bitter plants - a little in moderation. How long might I expect a dandelion to continue producing? In a tidy garden they're lucky to make it to a year, but clearly the deeper the root the more it can delve for minerals so would I treat it like a paeony for longevity, or aim to replace more frequently?

And with the blanching process - would you do that on a rotation? Say, one week in four?

I have never heard of dandelion haveing oxalic acid nor can I find any referance to suggest it.It contains citric and silicic acids and the bitter taste is due to taraxine and taraxasterol.
Herbman

herbman: however it might be, I like that bitter taste and enjoy little snacks while I'm weeding. Thanks for the extra info.

French and Italians love dandelion steamed and in salads. They have a few nice varieties (particularly suited for eating.... productive/better tastee etc.) Here are some American suppliers:

Seeds of Italy:
http://growitalian.com/Qstore/Qstore.cgi?CMD=011&PROD=1067218391
Pinetree garden:
http://www.superseeds.com/french.htm

Here is a link that might be useful: Harvest Moon seed (I've ordered from them. good service. good seeds)

Some cultivated dandelions are actually chicories.