Once your daffodils and tulips have finished flowering, it can be very tempting to mow the grass that surrounds them and cut down the leaves. However, you should wait until at least 6 weeks after flowering before mowing. If you want your bulbs to grow again the following Spring and look good and healthy, then do not cut down the leaves until they have started to wither and become yellow. After the bulb has flowered, the bulb is exhausted of food and nutrients. Food travels down the leaves to replenish the bulb so it’s important that you allow this to happen.
For perfect blooms the next year, fertilise the soil around the base of the leaves with a mix that is high in nitrogen, potassium and phosphorous. The bulbs need to dry out so once the leaves start to turn yellow, make sure you no longer water around them.
If some of your spring flowers have grown too close together then you can dig the bulbs up and separate them before re-planting or storing. If you really can’t stand the straggly, untidy look of the yellowing leaves, then you can tie them in a loose knot though they can be more prone to fungal diseases if you do this as you are restricting the air flow to the leaves.