It's a shame to mention it now while spring bulbs are in their glory, but they will fade, their wane is not usually pretty and now is the best time to plan a natural cover up.
Choose perennial companions for bulbs that will come up and spread fresh greenery over the aging bulb foliage. Or plant annuals to do that trick. It's a pretty solution that can free you from the odious chore of clipping back yellowing bulb leaves.
We call this design tactic "doubling up."
You've seen displays like these, with bulbs massed for maximum color. For this level of display there is no effective cover up. Such big bulbs in such dense plantings are removed after bloom. No kidding. We know this for a fact because we talk to lots of public garden gardeners, and because the luscious plantings in these five shots are from a garden we tend.
We don't mourn the bulbs we take out each spring. They were glorious and appreciated. They were not chosen for the ability to perennialize but for their one-time show. The garden itself couldn't support even the best perennializers -- it's too shady. So we whistle while we work as we pull the bulbs to put in summer annuals, just as we whistle while pulling those annuals in favor of mums and then new bulbs.
Bulbs rise early, shine and then fade while perennials that prefer warmer soil wait their turn. Groundcover plumbago (Ceratostigma plumbaginoides), hardy hibiscus (H. moscheutos and its hybrids), Joe pye (Eupatorium species), Japanese anemone (A. x hybrida) and others are late risers that can work to cover bulbs.
Yes, you can cut back bulb foliage when the bulbs are done blooming. We've explained cutting back bulb foliage before, in What's Coming Up 45. (It does not contradict the "let foliage yellow first" rule; the two approaches simply serve different objectives.) We won't discuss it now because the point is to avoid that work!
This is a cover up by planting annual plugs among the bulbs, or sowing annual seed. Not to be confused with removing spring bulbs that were planted only for a single showing, and replacing those with annuals.
Of planting or sowing, we prefer sowing. It's so simple to spread seed as the bulbs break the surface, and then simply avoid weeding out what we've sown. (We do not mulch heavily among bulbs we expect to be companioned by annuals, or we rake the mulch away in that spot in early spring so annual seed can sprout.)
Even better, choose an annual that will seed itself back into place year after year. Annual alyssum (Lobularia maritima), pot marigold (Calendula officinalis), love in a mist (Nigella damescena), snapdragons (Antirrhinum majus), spiderflower (Cleome hasslerana), giant Himalayan impatiens (I. glandulifera) and others are reliable self sowers. We pick one that's suited to the site (alyssum wants sun, giant impatiens prefer shade, etc.), plant that once and let it those plants seed themselves. The chore then is keeping that annual in check, removing it when it appears where you don't want it and thinning the better-placed volunteers so that the remainder put on a good show.
In our articles profiling the spring bulbs, we show you many examples of doubling up to cover bulbs: anemone sharing space with lady's mantle (Alchemilla mollis), tulips chumming it with sea kale (Crambe maritima), daffodil leaves emerging alongside sedum 'Autumn Joy', and glory of the snow blooming through last year's fallen tall phlox stems. The best of such combinations are larks with owls, vase shaped with mats, deep roots with shallow, and sturdy characters with twiners. In the outline and charts we provide when speaking to groups about doubling up, you can look for combinations that work for you. Download that doubling up chart.
In the spring, you can easily see where you will need cover up, and garden centers are full of what you need. In the fall when bulbs are readily available, garden centers are often out of stock of the companion plants. In addition, the impact of a bulb planting is invisible in fall: plant a hundred bulbs, turn away for a minute and you will forget where they are!
So we mark places now to add double-up companions, and buy small new plants to insert among bulbs or make divisions of existing perennials and tuck those in.
In the next photo, you see Janet in fall as we planted netted iris bulbs to grow through this artemisia 'Silver King'. We cut out the king's center, set the bulbs, then filled over them with compost enriched soil and lively young divisions from the outer edge of the artemisia.
What we like better is to make those combos in spring. Then, we can eliminate steps: nab a few artemisia divisions and tuck them in among emerging iris
We also divide and relocate bulbs in spring. What better time since it's plain to see where we need more yellow, which crocuses are white, whether the purple 'Negrita' tulips have sufficiently light colored backdrops, etc. (More on moving bulbs in spring, in What's Coming Up #140, page 10.)