Covering up for spring bulbs' wane

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."

Glory of the snow (Chionodoxa, the upfacing single flowers), squill (Scilla, dark blue pendant blooms) and Puschkinia (multiple blooms, white striped with pale blue). Spring bulbs are so beautiful it's a shame to think about covering them up, yet that's what we do!

Glory of the snow (Chionodoxa, the upfacing single flowers), squill (Scilla, dark blue pendant blooms) and Puschkinia (multiple blooms, white striped with pale blue). Spring bulbs are so beautiful it's a shame to think about covering them up, yet that's what we do!

Cover-less: Bulbs as annuals
Larks and owls: Late-rising perennials to hide early bulbs
Annuals as cover up
Many more options
Why spring
is the time to do the cover up

You've probably seen and admired tulips massed like this...

You've probably seen and admired tulips massed like this...

First things first: Bulbs as annuals

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.

There are over 200 bulbs planted on either side of the little wattle fence. The lush fresh foliage is beautiful in itself... but it's not even all up yet.

There are over 200 bulbs planted on either side of the little wattle fence. The lush fresh foliage is beautiful in itself... but it's not even all up yet.

In bloom, leaves still expanding, the bulbs allow no sun to reach the soil. If there were perennials interplanted, they would be suppressed and emerge weakly.

In bloom, leaves still expanding, the bulbs allow no sun to reach the soil. If there were perennials interplanted, they would be suppressed and emerge weakly.

We extend the bloom time of the group by mixing species, but that doesn't alter facts. These 100+ Muscari and tulips are destined for the compost, post-bloom.

We extend the bloom time of the group by mixing species, but that doesn't alter facts. These 100+ Muscari and tulips are destined for the compost, post-bloom.

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.

Larks and owls: Late-rising perennials to hide early 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.

Even late rising companions need some sun and a bit of elbow room to get a good start in spring. If you double up with big, late bulbs you will have to divide them to maintain space for the second shift.

Even late rising companions need some sun and a bit of elbow room to get a good start in spring. If you double up with big, late bulbs you will have to divide them to maintain space for the second shift.

Where bulbs are doubled up with perennials in a garden the effect is color in splashes, not solid masses.

Where bulbs are doubled up with perennials in a garden the effect is color in splashes, not solid masses.

After bulbs have bloomed you can cut their foliage back to make room for the owlish perennials that are their companions... or in this case the deer browsing there have cut back for us.

After bulbs have bloomed you can cut their foliage back to make room for the owlish perennials that are their companions... or in this case the deer browsing there have cut back for us.

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!

Annuals planted or sown among bulbs

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 this bed we designed and tended at the Detroit Zoo for many years (it's under the wolf exhibit now!) Japanese anemones, daylilies, sea kale and self-sown perilla and butterfly plant doubled up over all these bulbs.

In this bed we designed and tended at the Detroit Zoo for many years (it's under the wolf exhibit now!) Japanese anemones, daylilies, sea kale and self-sown perilla and butterfly plant doubled up over all these bulbs.

Here we use the almost-annual golden bleeding heart (Corydalis lutea) as a double-up where squill and glory of the snow gather. The golden bleeding heart is perennial but also sows readily and blooms the first year from seed.

Here we use the almost-annual golden bleeding heart (Corydalis lutea) as a double-up where squill and glory of the snow gather. The golden bleeding heart is perennial but also sows readily and blooms the first year from seed.

Many more options

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.

The blue flowers are not biennial forget me not but the blooms of bigleaf forget me not (Brunnera macrophylla). Brunnera's big leaves emerge after the bloom is done, and will efficiently cover all the fading anemone- and tulip foliage.

The blue flowers are not biennial forget me not but the blooms of bigleaf forget me not (Brunnera macrophylla). Brunnera's big leaves emerge after the bloom is done, and will efficiently cover all the fading anemone- and tulip foliage.

Perennial geraniums are just beginning to emerge from between the tulips. In summer no one will know all those grape hyacinths or tulips exist!

Perennial geraniums are just beginning to emerge from between the tulips. In summer no one will know all those grape hyacinths or tulips exist!

Bulbs can be very effectively covered up by woody plants treated as perennials and cut to the ground every spring. (Buddleia/Butterfly bush stubble circled above. Have no fear, it will rise again!)

Bulbs can be very effectively covered up by woody plants treated as perennials and cut to the ground every spring. (Buddleia/Butterfly bush stubble circled above. Have no fear, it will rise again!)

Why it's a good time to double up now

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.)