Chicken wire is protecting this bed of tulips from burrowing rodents. The tulip shoots are able to emerge through the openings. George Weigel

The bulbs are a no-show

Most puzzling is when bulbs planted in fall simply never come up in spring.

That usually traces to three explanations:

1. The bulbs were dead on arrival. Fresh, quality flower bulbs should be firm and fleshy. Bulbs that haven’t been cured and stored properly can either rot or dry out in the bag.
   
   Inspect bulbs before buying (if possible) and before planting. Toss any that are soft and beginning to rot or that are papery and light-weight from drying out.
2. The bulbs rotted in wet soil. Most bulbs demand well drained spots with loose, rich soil. If you don’t have that, create raised beds by improving the soil before planting with compost, rotted leaves, or similar organic matter.
3. Rodents ate the bulbs. Hyacinths and crocuses are occasional targets, but tulips are particular favorite meals of squirrels, chipmunks, mice, and voles.

One option is to stick with species that rodents don’t like, such as daffodils, Siberian squill, ornamental onions (Allium), glory-of-the-snow, snowdrops, fritillaria, striped squill (Puschkinia), summer snowflakes, Spanish bluebells, and “Tommy” crocuses (Crocus tommasinianus).

Otherwise, discourage rodents by covering the ground after planting with a sheet of chicken-wire fencing. (Shoots will come up through the openings.) Or dig a planting trench, line the bottom and sides with fencing, plant the bulbs, backfill the soil, then lay another sheet on top to create a protected fence box.

Cutting bulb foliage before it’s mature short-circuits the bulb’s ability to recharge itself for next year’s flowering. George Weigel

The bulbs produce leaves but no flowers

Sometimes bulb shoots come up, but the plants don’t produce flowers.

Five possibilities explain most non-blooming:

1. The bulbs are planted too deeply. A good rule of thumb is to plant bulbs two-and-a-half to three times as deep as their height (including any mulch added after planting.)
2. Cutting the leaves off too soon after bloom. Cutting or braiding the leaves while they’re still green short-circuits the bulb’s access to sunlight, which is what fuels next year’s blooms. Wait until the foliage dies back naturally before removing it… or at least wait until the foliage yellows before cutting.
3. Lack of sunlight. Most bulbs need at least six hours of sunlight a day to bloom well. Plant them in sunny locations or relocate them to a brighter spot if blooming is lacking.
4. Poor soil nutrition. Bulbs usually flower in even moderately nutritious soil, but if your soil is really out of whack, it’s possible the bulbs aren’t getting the necessary nutrients for flower production. Testing the soil is the best solution, but you could try topping the bed with compost or a scattering of fertilizer formulated for bulbs.
5. Sudden, severe freezing weather. Bulbs are generally cold-hardy, but an unusually cold or late freeze can wipe out flower buds. Other than covering bud tips with a sheet or floating row cover when a severe freeze is forecast, there’s not much you can do about damaging weather.

This bed of tulips has fizzled out considerably just two years after it was fully planted. George Weigel

The bulbs go downhill after a few years

Tulips in particular often flower only one or two good years before becoming non-bloomers or dying altogether, but other species also can fizzle with age.

Sometimes the problem is over-competition – when bulbs become too crowded for the limited space and nutrients. Digging, dividing, and replanting the bulbs after the foliage dies in spring is a possible bloom restorer.

The aforementioned problems with lack of sunlight (which can happen over time from nearby growing trees) and poor nutrition also can explain this one.

If dividing and fertilizing don’t help, replace the bulbs with fresh ones.

The bulbs grow abnormally tall (or short)

Bulbs can grow "leggy" and flop over when they’re not getting enough sunlight or when they’re over-fertilized. Some varieties are just naturally tall and flop under the weight of rain or wet snow.

Stick with compact bulbs at planting time if you don’t like floppers (labels and catalog listings usually list height), and go easy on fertilizer (more isn’t better if plants are blooming well). 

Another option is erecting "corrals" around the perimeter of flop-prone bulb groups by hammering in bamboo stakes wrapped with jute or twine.

The opposite problem is when bulbs grow abnormally short, which is usually a result of compacted soil but also can happen from too-late planting.

Bulbs planted too late often will go on to grow normally after a year of adjustment, while replanting bulbs in loosened and improved soil usually fixes soil-compaction problems.

Daffodils usually slough off cold nights and even dousings of snow. George Weigel

Bulb shoots emerge while it’s still winter

This is happening more and more in our increasingly erratic weather. Warm spells that follow cold spells over winter sometimes trick bulbs into thinking spring has arrived before it really has.

That causes bulb shoots to poke up prematurely, creating worries that a return of cold will kill the bulbs.

While cold can brown the tips of premature shoots, it usually doesn’t cause serious or lasting damage to the buried bulbs themselves – or even to that year’s flowers.

If you’re concerned, cover plants overnight with a sheet or floating row cover. And insulate bulb beds with about two inches of mulch heading into winter.