How to Manage Dying Spring Bulbs
Frankly I cringe when I see people mowing down, or worse, pulling out, their tulip bulbs and cutting off the top greenery. Granted once bloomed, tulip and daffodils are on the down side of pretty, leaves turning yellow as they shrivel up and melt into the landscape. That is precisely the point; they should be allowed to gently fade away.
In the process, these bulbs, as most other plants, are still taking in sunlight they turn into energy that gets stored in bulbs. The energy then is taped next time they grow and, if they have enough, they will bloom again.
Tulips, daffodils and other spring-blooming plants need to collect the energy through their leaves if they are going to have enough energy to bloom again. Without it, they will use up whatever energy they have stored and either just grow leaves next year, or die.
I understand the remaining greenery is not attractive so what to do about the ugly greenery. I plant other flowers in front and around the daffodils and tulips so they will grow and overtake, or cover up, the yellowing leaves.
If you want to save the bulbs, dig the up with the greenery still attached. The plant may continue to grow after it is out of soil so keep their version of being solar powered available to the plant or it may die.
These tulips, for example, can be moved after blooming as long as the green tops are left attached to the bulbs. If you cut them off, the bulb has no way to collect sunlight and, through photosynthesis, turn it into energy and food it stores in the bulb.
The same applies to mowing them over, cutting off the greenery, walking across it - anything that detaches the solar panels of a plant, the leaves, from their storage area - the bulbs.
Even if you don’t have anything to camouflage the yellowing leaves, the dying off process will take a very short time so be patient!