Hopefully your yard is not covered in dandelions, but what do you do with them? Is this the right timing for an application to get rid of them? Or are they beautiful just the way they are?
Quick Life Cycle Note
Dandelions are a perennial weed that we deal with on a regular basis. They are very common and commonly hard to control at times. They flower in the spring and go to seeds. The seeds can then start to develop over the summer and create new plants for in the fall. They will then over-winter in our lawns waiting for the warmer temps the following year. In the spring the new plants will flower and produce seed, but they don't die. The 'new' plants will stay there and keep the cycle going.
What do I do?
One option is to say that geeze, they are a flower and relatively pretty....It's just that most accept them as a weed in the 'lawn'. Most others debate the time of year to treat them and there can be great debate on this topic. There are a few factors to consider when wanting to control them: how many application do I want to do, how much money do I want to spend, and how dedicated am I to getting rid of them? The amount of application and cost go hand-in-hand as the more applications you do, the more costly it will be. The major decision is can I always live with a few or do you want to hopefully never see their yellow head again! (Granted, 100% control is impossible. Some will always come from neighbors, birds/wildlife, the wind, etc.).
If you want to put all your 'eggs in one basket', the recommendation is to wait until the fall to control them with a broadleaf weed killer. You may think they are not a problem in the fall, but that is the time of the year when they are putting resources into the ground for next year. Therefore, if you put a product on at that time to kill them, they will take it down and it will kill the root of the plant, which is the most important thing. You can 'burn' the foliage off, but the root, especially their taproots, stores lots of nutrients and it can restart foliage when it's burned off when an herbicide treatment. That is why this gets the most for your money and could be the only treatment you do. Granted, it may take longer as you have the spring seed produce you will fight each year. However, you can hopefully kill most of those off each fall.
Now, spring treatments do have a place. This treatment can help to kill the flowers so that no more seeds are produced to create more plants. The treatment may also kill the foliage off, but remember that it doesn’t necessarily kill the root. Therefore, the plant may come back from the taproot during the summer. If you do not follow-up with a fall treatment, that plant can then get enough resources that it still may flower again next spring. So if you are going to treat in the spring, you should treat in the fall to make sure the plant is actually killed off instead of just the foliage.
For information on products that can be used or on other broadleaf weeds, check out this publication on Control of Broadleaf Weeds in Home Lawns.