Magazine article Sunset

How Deep to Plant Daffodil Bulbs? Chill Then or Not? We Put Them to the Test

Magazine article Sunset

How Deep to Plant Daffodil Bulbs? Chill Then or Not? We Put Them to the Test

Article excerpt

Testing the rules is one way to expand your gardening knowledge. When you see the reasons behind the rules clearly, you understand better how far you can bend them to suit your own circumstances and desires.

How deep should you plant a daffodil bulb? Should you chill the bulb before you plant it?

To find out, we tested early and late kinds to daffodils in each of the West's four major climate zones. Photographs at left and on page 261 show the results in Southern California; beds in the Northwest and the desert are pictured on page 262.

Results were clear and consistent for all three daffodil varieties we planted. Shoots in each section emerged and bloomed all at once--chilled bulbs bloomed one to three weeks before unchilled ones planted at the same depth; shallow ones bloomed a week or more before those at the next depth. Only in Seattle was this staggering of bloom less pronounced. Know the rules before you break them

Chilling daffodils is not essential and only recently has been recommended for mild-winter climates. The traditional planting depth is two to three times the diameter of the bulb--froughly 6 to 9 inches deep for daffodils as large as these.

This is no doubt the safest all-around depth--deep enough to protect bulbs from frost and summer heat, but shallow enough to avoid minor soil or drainage problems.

But our tests show that there are conditions where other depths may be preferable. And chilling the bulbs definitely yields earlier bloom and an extra margin of safety in mild-winter climates. Putting test results to use

You can spread bloom over a longer period by the following methods. For more predictable results, experiment with either depth or chilling, but not both in the same bed.

Choose early, midseason, and late varieties. The natural timing of a variety proved the strongest influence on bloom sequence. You can find the bloom season from nursery labels or bulb catalogs.

Chill half the bulbs. In mid-winter climates, refrigerate half the bulbs of each variety for six to eight weeks before planting. Store them in paper bags so air can circulate.

Plant at different depths. For the same variety, a 3-inch increase in planting depth meant a five- to eight-day difference in bloom time in both areas or California and in the desert.

For maximum impact at each sequence of bloom, be precise in planting all bulbs in the same group at the same depth. Plant the deepest or latest-blooming bulbs in front to mask the decline of earlier-blooming ones in back.

To delay bloom on early varieties (some bloom by Thanksgiving in California), try planting deeper than usual.

In climates where soil freezes in winter or bakes in summer, stay close to the traditional depth if you leave bulbs in the ground all year. …

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