Daffodils say "spring" better than any other flower. If you forgot to plant daffodil bulbs in the fall, it is still possible to plant them in late winter or early spring. Nearly every gardener has discovered a bag of daffodil bulbs lurking in the garage or garden shed after the ground has already frozen. Or, spring may be approaching and you realise you never bought bulbs at all. You can still have daffodils if you act fast.
Examine the daffodil bulbs. Keep the ones that are firm, plump and feel heavy. If bulbs appear to have spots on them, peel back a few of the papery layers and check for disease. Discard any bulbs that are mushy, soft, or dried out.
Check the soil. Is the ground in a hard freeze state or just a frozen crust? Bulbs are hardy; you can still plant the "forgotten" bulbs during the January thaw or anytime in February. If it is possible to plant now, proceed to Section 2. If the ground cannot be worked due to deep freeze winter conditions, continue to Step 3 below.
Chill the bulbs. Daffodils will grow even if they are not chilled, but will not flower well with a chill period of less than 12 weeks, preferring 16 weeks of temperatures lower than 15.6 degrees C. Even if the combined refrigerator plus ground chill time is only eight to 10 weeks, you will still get some results. Fortunately, the average temperature in a refrigerator or unheated garage works just fine. Place the bulbs in a loosely closed paper bag or in a mesh bag so that some air gets in. Do not enclose the bulbs tightly or place in plastic, which encourages rot. Check the daffodil bulbs periodically to ensure they are not near moisture or exposed to drafts.
Find a site that is sunny and well drained. In the fall, daffodil bulbs can even be planted under deciduous trees as most of the growth is finished before the trees finish leafing out. For a later planting, however, sun is needed to ensure growth and bloom. Because you are planting in spring, avoid overly wet areas, or use raised beds.
Dig the holes. Use a garden fork to loosen the soil. Dig holes to a depth that is about three to four times the height of the bulbs. Daffodils look best in groups of three to 12 or more. Since not all the bulbs may grow or bloom from a late planting, it is advisable to plant at least six bulbs per hole.
Place, space and cover the bulbs. Position bulbs, pointy end up, 4 to 6 inches apart. Return the soil gently to the hole, keeping bulbs upright. Then pat and press the soil in place firmly. Water thoroughly unless you are doing a winter planting, breaking through the soil crust. In the case of freezing air temperatures, do not water, but try to press the earth against the bulbs so that they are not exposed to the air. Then mulch with straw or leaves.
Fertilise lightly when the shoots emerge. When shoots are about 4 inches tall, use a low-nitrogen fertiliser where the first number is half or lower than the second two, such as 5 -10-10 bulb fertiliser. Follow the package directions to apply. Only do one fertiliser application and keep it a light. Do not over fertilise.
Keep expectations modest for this year. You will have the most success with your late planting for early daffodils varieties that are good for naturalising, like Thalia, Jack Snipe or Carlton. The early varieties are able to flower with the shortest growth period. Mid-season types may have less success and late season types could have few flowers. Since most daffodils are hardy, chances are you will have a better display the following year and at least some flowers this year.
Allow foliage to remain after the flowers bloom. You can cut down the flower stocks, but leave the leaves to feed the bulb for next year. After the leaves have turned brown, they may be removed.
In the southern U.S., plant Tazetta or Jonquilla strains which don't need to be chilled.
To avoid rot, do not fertilise bulbs at spring planting time.