Harvest roughly 8 cups of dandelion flower heads. Carefully remove just the yellow petals, discarding the green portions. You should have roughly 4 cups petals (not packed) or 2 cups petals (packed).
Make a dandelion petal tea by pouring 4 cups boiling water over the cleaned flower petals. Allow the tea to steep for at least an hour, but as long as 24 hours.
After steeping, strain the petals, ringing them out to get every last bit of liquid. Measure the liquid, you should have 3 3/4 to 4 cups of dandelion tea.
Pour the dandelion tea into a heavy-bottomed saucepan. Add lemon juice and pectin, and bring the mixture to a boil over high heat. (Note: Do not add sugar yet.)
Once the mixture is rapidly boiling, add the sugar and stir to combine.
Allow the mixture to return to a hard boil, and boil 1-2 minutes before removing from heat.
Pour the jelly into prepared jars, seal and allow the jelly to cool and set for at least 12 hours. (Sometimes jelly takes as long as 48 hours to fully set, be patient.) Store in the refrigerator.
Notes
Dandelion jelly is like sunshine in a jar, and it's the perfect way to brighten your morning toast.