Seems like a good idea. I grow daffodils in a spot where they have to "suffer" being covered with squash, beans and tomatoes while they are dormant. Probably not ideal moisture conditions for the dormant bulbs, but with space kinda limited I don't want to leave the area idle all summer while the bulbs just sit there.

I don't see why a straight cover crop would be much different... still I'd rather just mulch if it was a summer growing bulb such as a lily.

It sounds like a good idea, although you have to make sure to coordinate the timing of everything for it to work. Usually, cover crops are mowed right before they bloom, and that moment has to be after the leaves have fallen off the lilies. Choose the cover crop wisely.

One thing you can do that would involve less work is to plant perennial legumes that don't spread and take over. They will shade the soil for your bulbs so that it retains moisture, feed the soil by fixing nitrogen and hide the yellowing leaves of your bulbs. Oxalis and lupine come to mind. No need to mow these, just water when it gets dry. In spring, your bulbs will grow right through these plants.

viktoria - are you sure about the oxalis idea? The OP might want to think very carefully before planting Oxalis in their garden. It is horrendously invasive and it isn't a legume or a nitrogen fixer.

If you decide to plant perennial ground cover why not just have mixed bed of which bulbs are just one element? That way it can be interesting all year round and not just in one season.

I'm growing these bulbs for cut flowers so I'm planting whole beds of one thing that gets all cut off at once. Also some bulbs don't like to be disturbed, like Crocosmia and Amaryllis. In theory it seems like I could grow a winter legume (like hairy vetch or crimson clover) cover crop over the bed and then mow it off in the spring before any leaves from the bulbs come through the soil. I would be hesitant to plant a perennial cover crop like white clover for fear that it would compete too strongly with the bulbs.

I am not sure now about oxalis being a legume and a nitrogen fixer, I categorized it that way in my mind for that use, but maybe it is for some odd reason I did so and I am nowhere near right. Maybe its resemblance with clover? When I was investigating oxalis, I was going to plant it in a lawn...

But I do feel the need to defend oxalis as merely hearing the name makes palms sweaty all over the place. Most varieties are invasive, even highly invasive, but some are not. For instance, Oxalis versicolor, magellanica, purpurea, crassipes. Most of these do spread, however, so they are ideal as a ground cover and they do need to be kept in check.

Steve, I am not sure if it is feasible to mow your cover crop in early spring before bulbs leaf out. I am only in zone 5, and as I learned recently, two zones away is a whole different world, so I might be wrong. But bulbs usually pierce the ground here as soon as the soil thaws, and there may be bulb leaves just below the surface when you plan to mow the cover crop. To be on the safe side, you may want to think about planting a cover crop that needs to be mowed in fall; I think that would be a much safer alternative. Buckwheat comes to mind. It is usually mowed in summer or early fall, depending on when it would bloom for you (and when you sow/plant it). It also grows really fast and you could even start sowing it once your bulbs have gone to sleep.

What I am trying to say is that my limited knowledge tells me that bulbs should only be tampered with when they sleep soundly.

Having said that, the vetch idea is neat and would most likely look pretty good as well.

What about a ground cover which is killed by frost and doesn't need mowing? Nasturtiums would do it although they aren't nitrogen fixers.

Regarding the Crocosmias - they are evergreen clump formers and I can't quite see how you'd manage a cover crop around them.

Crocosmias are not evergreen in my climate. The leaves freeze and die and then the plant returns the next year from the underground corm.

Wow - it must get cold. They are evergreen in the UK and I assumed, wrongly, they would be anywhere. In fact the plain old Montbretia is a weed in some areas here. It's taken me ages to get rid of it from my garden and I still find the odd shoot.

Here is a link that might be useful: Eradication of montbretia