After your tulips fade, snip off the spent flowers and let the green leaves keep growing until they yellow on their own. That single habit is the core of good tulip care after blooming, because the leaves are still feeding the bulb for next spring. Do not cut them back early, and do not braid or tie them up either.
One May I worked down the back border by the garden path, clipping the brown, drooping heads off a row of tired tulips. I left every yellowing leaf standing, even the ones flopped across the soil. The next spring that same row pushed up and bloomed again, fuller than the year before.
Here is what is happening under the surface. The green leaves run photosynthesis and pump sugars down into the bulb, which stores that food to build next year's flower. Deadheading tulips as soon as the petals drop stops the plant from making a seed pod. A seed pod drains a lot of that stored energy, so cutting the flower stalk sends the food back where you want it.
Timing the two cuts matters. You remove the flower right away, but you leave tulip foliage in place until it turns yellow and limp. You will find the same rule from the University of Maryland and Minnesota Extension. Cut the leaves too soon and you starve the bulb. A starved bulb often skips a year or fades out for good.
I learned to trust the yellow stage by watching my own beds. The first season I tidied early, half my tulips came up blind the next spring with leaves but no flower. So now I wait. The leaves can flop and brown and look messy for a few weeks, and I let them. A little mess in May buys me a fuller show the year after.
Give the plant a little help while those leaves stay green. Water lightly during dry spells so the foliage keeps working. Skip heavy fertilizer on a fading plant, since the bulb mostly needs sunlight and time now. The leaves will wither in four to six weeks, and that yellow, papery stage is your signal that the bulb is full and the cleanup can start.
Deadhead the moment petals drop, then leave the foliage alone until it yellows on its own. Pull the dead leaves only after they slip free with a gentle tug.
Once the foliage yellows, you have two solid paths. In well-drained ground, hardy tulips can stay right where they are through the off season. If your soil stays wet, or you want bigger blooms, lift the bulbs after the leaves die back and store them somewhere cool and dry. Brush off the loose dirt, toss any soft or moldy bulbs, and keep the good ones in a paper bag or mesh tray with some airflow. A spot near 60°F (16°C) works well until fall planting time.
Either way, plan to dig and divide a clump every 3 to 4 years so crowded bulbs get room to bulk up again. Over time a single bulb splits into smaller offsets, and those offsets compete for food and space. When you pull a clump apart, replant the fat bulbs at the right depth and set the tiny ones in a nursery row to grow on. This is also your best chance to fix poor drainage by mixing grit or compost into the planting hole.
Stick to this rhythm and your tulips reward you. Deadhead fast, let the leaves do their job, water a touch, then leave or lift the bulbs. Crowded bulbs every 3 to 4 years get a split, and the rest take care of themselves.
Read the full article: Tulip Bulbs: The Complete Planting Guide
