Q. What bulbs are resistant to nibbling and digging by animal pests like deer, rabbits, squirrels?
Q. When do I feed flower bulbs?
Q. Why didn’t my daffodils bloom well? I have lots of green foliage, but few flowers.
Q. Can I braid or tie up or remove the messy foliage of my daffodils and other bulbs after bloom?
Q. When can dahlias and tender bulbs be planted outdoors?
Q. Do dahlias need pinching?
Q. Which flower bulbs will perennialize and come back year after year?
Q. My lily foliage was damaged by lily beetles. What can be done to prevent or eradicate them?
A. Daffodils, or Narcissus, are poisonous, and therefore seem to have all-round resistance to nibbling or digging by animals. The ornamental onions (genus Allium) have a built-in repellent as well, with that onion-y smell of theirs. I can attest to many years of experience with nobody bothering those, as I can to the apparent animal-proof nature of Camassia and most Fritillaria (though I have had skunks dig up the small ones many times while rooting around in the beds here; funny that they’d dislodge skunky-smelling Fritillaria, those skunks).
Hyacinths and foxtail lilies (Eremurus) are also rated for deer-resistance; I cannot offer any first-hand insight, only friends’ reports (and those in catalogs and books).
Do not even think of growing tulips or lilies (Lilium) without protection.
Among the minor bulbs, crocus are, sadly, delicious animal-bait, too (though C. tommasinianus is said to be more resistant than others; I have failed with it when squirrels or chipmunks felled the stems in spring or beheaded the just-open flowers). Animal-resistant choices include snowdrops (Galanthus); snowflake (Leucojum); winter aconite (Eranthis); glory of the snow (Chionodoxa); Spanish bluebell (Hyacinthoides hispanica); Ornithogalum, Scilla, Muscari (grape hyacinth). The so-called autumn crocus (Colchicum), with its late flowers, are also apparently not tasty.
I have had good success here with all but the true Crocus, though extra-deep planting and a sprinkling of bloodmeal on the soil surface as they pop through is said to deter the incessant digging by chipmunks and squirrels.
Some gardeners enclose delectable bulbs in hardware-cloth “cages” that they fashion as underground dig-proof protective devices, but that eventually ends up like a prison as the bulbs multiply and also looks unnatural (I have actually seen a rectangular “clump” of crocus the precise shape of the underground device; ugly).
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A. Though bulb companies sell fertilizer at shipping time in the fall and say to add it to holes then, I have to say I never do. The best time to feed bulbs is when they begin active growth, when the green shoots are emerging.
Use an all-natural organic fertilizer, not chemical-based ones; select a formula intended for bulbs. Apply according to label directions. Expert sources like the American Daffodil Society recommend reapplying fertilizer at bloom time as well (again, I feel good if I get the one application on at first sighting of the greens).
After they flower, deadhead the spent flowers only, but let the foliage wither on its own. This is how bulbs feed themselves—so don’t cut off the greens until they die back, at least 6 weeks later.
Quick tip about a bulb you might not have thought of feeding: garlic. Spring’s the time (when the greens are starting to push up into active growth) to feed it, too.
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A. I had always thought my daffodil drifts were “forever,” too, but lately some old naturalized clumps here have fewer flowers than in previous years. In my case, that was because limbs of trees and shrubs on the sunny side of them had grown over the years and cast more shade, something most flower bulbs don’t appreciate. Judicious pruning helped the clumps get reinvigorated.
Generally, when plants of any kind don’t bloom it’s usually an issue of either not enough light; too much nitrogen (which makes green, not flowers); too little of the other nutrients they need; or overcrowding (particularly relevant in the case of bulbs, which can multiply underground), but also including competition tree and shrub roots for water and nutrients. Improperly timed pruning (cutting back the foliage too soon) can diminish bloom as well.
Sometimes the wrong variety (for example, one that needs more weeks of winter chill to develop than your climate offers) can be the reason for flower failure, Brent Heath of Becky’s Bulbs, a Narcissus expert, explained in this interview…along with more daffodil tips.
A checklist of causes:
- Are you feeding with high-nitrogen fertilizer (the first number in the N-P-K ratio should be low; high N=no flowers, so bulb fertilizers aren’t high N)?
- Did you neglect to feed for more than a year or two? Feed bulbs when they begin active growth, when the green shoots are emerging. Use an all-natural organic fertilizer intended for bulbs. Apply according to label directions.
- Did you cut foliage back too soon last year? (At least 6 weeks of “ripening” time is needed, with their foliage growing and intact, is needed. In Zone 5B in the Northeast, I remove spent foliage July 4th each year, even though the Narcissus bloomed in April and early May.)
- Is the area very dry? Bulbs need ample moisture when they are in active growth. (On the other hand, a soggy area is harmful to them.)
- Is the area filled with tree roots, or with other competing plants who grab all the nutrients and moisture? Areas under evergreens can be inhospitable, for instance (ad well as too shady). Dividing may be called for (or transplanting to another, better-suited area).
- Were the bulbs recently planted or recently transplanted? Both can set back the bulbs for a time.
A. Bulb foliage must be left intact for at least six weeks to conduct photosynthesis, ripen the underlying bulbs and insure next year’s flower production. Again: I leave mine intact till July 4th each year, more like 8 or even 10 weeks, because that’s when it really fades naturally here and I am certain it is done doing its job.Tying the foliage into braids or tucking it inside rubber bands does not allow for maximum photosynthesis; don’t do it. Leave the foliage on the plant until it shows signs of withering on its own, then remove carefully so not to dislodge the bulb.
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A. Wait until all frost danger is past, or just before then. To give dahlias and other tender bulbs a head start, pot them up for a few weeks in potting soil and leftover nursery pots, and grow them indoors. How to grow (and then later on store) dahlias, with advice from Roger David of Longwood Gardens.
For instance, I put my cannas (which I dig and overwinter in the basement), into nursery pots for a headstart and tuck them in the garage, which isn’t heated but stays cozy compared to outside at night in earliest spring. I drag them out into the sun in the daytime, then back in. If you just had a few pots, you could do it indoors in the house in a warm spot. Or your could forget the headstart step and just put the tubers straight into the ground shortly before your frost-free date.
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A. It’s good to pinch dahlias to promote a really bushy plant with lots of flowers. When the plants are a foot or a foot and a half tall, you’ll have about three sets of leaves already fully developed, so pinch out the growing tip above the third set of leaves (leaving all three sets intact below that). My friend, organic flower farmer-florist Jenny Elliott, explains her dahlia-growing regimen, including pinching.
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A. The response of bulbs (like any plant) will vary greatly from region to region, and even season to season, and is also influenced by how you plant them and care for them.
Generally speaking, daffodils (Narcissus) will be longer-lived than, say, tulips…but even some Narcissus will falter in the wrong climate, certain ones preferring the cooler or warmer ends of their hardiness range.
Lilies, Spanish bluebells (Hyacinthoides hispanica), Scilla, Camassia, snowdrops and snowflakes (Galanthus, Leucojum), glory of the snow (Chionodoxa), winter aconite (Eranthis) and trout lily (Erythronium) are others that are more inclined to stick around. Crocus would, but are usually gobbled up here by chipmunks or squirrels.
If you want tulips that last, invest in the botanical, or species types (which are usually much smaller than the big Dutch hybrids, with a beauty of a more refined nature).
With some bulbs (like tulips) deeper planting will yield a longer life, making them slightly more “perennial.”
Important: Scan high-quality bulb catalogs for “bulbs for naturalizing” to find longer-lasting choices. Again, response depends on so many factors. There are some hints in the following documents, and their customer-service line should provide even more, based on feedback from customers in different zones.
Speaking of perennials: The best uses of bulbs from a design standpoint often include clever herbaceous perennial companions, that arise later and hide the fading bulb foliage while it ripens. Lisa Roper of Chanticleer Gardens in Pennsylvania gave me a tutorial on designing with bulbs and choosing good partners for them.
A. I have very few lilies (like several clumps of martagons only on my several acres) and am in a very rural area without other host lilies in gardens for them to be lured to, but I did finally get lily beetles anyhow.
But I have done some reading, and it seems that vigilant observation, hand-picking early and often, and perhaps the use of a Neem-oil spray on the larvae are somewhat helpful.
In 2017, I got a 101 on the beetle from Lisa Tewksbury, and we talked about those tactics and more. She is manager of the University of Rhode Island’s Biological Control Lab in Kingston, where she coordinates research on the lily leaf beetle, among other invasives. Learn what’s being done by scientists seeking solutions other than chemical herbicides or pesticides, and what you can do in your own yard if you have them, too.
- B&D Lilies has a detailed page about lily beetle; Gardener’s Supply also had an interesting fact sheet on it.