Bulb Size. For most Narcissus, the minimum bulb size for
flowering is 12 cm, in circumference. The exceptions would be some of the very
small bulb producing types or cultivars. Providing the bulb is greater than
12 cm, in circumference, hardy Narcissus begin to form their flowers
about one month after the plants flower in the spring. They reproduce by offsets.
Tender III Types (Paperwhites and other Tazettas). Before planting,
store bulbs in a well ventilated area and open trays or boxes at 55-65°F
(13-18°C). They are normally
planted in October and begin flowering in December or January (first year) under
cool-moist conditions. The leaves and budded flowers will tolerate a frost.
However, open flowers are readily damaged by frost. They senesce in spring and
the bulbs over summer under well drained (dry) conditions. The flowers form
during the warm summer months. Bulbs reproduce by offsets.
Hardy I and II Types. Before planting, store bulbs in a well ventilated ethylene-free area in open trays or boxes at 55-65°F (13-18°C). For Climate Zone 10, bulbs should be precooled at 45-50°F (7-10°C) for eight weeks before planting in an area with good air movement to minimize the development of Penicillium.They must be planted in fall as indicated below.
|
Optimum Planting Period
|
|
| 3 | September |
| 4 and 5 | September to early October |
| 6 | October |
| 7 and 8 | November to early December |
| 9 | Late November to early December |
| 10 | December (primarily precooled at 45-50°F (7-10°C) bulbs) |
Hardy bulbs begin to root when soil temperatures are < 63°F (17°C) and have a specific cold requirement to promote floral stalk elongation and flowering.
Approximate Planting Density (bulbs per square foot) Chart for Flower Bulbs
|
Bulb Size
(cm, in circumference)
|
Spacing
(inches) between bulbs
|
|||||||||||||
|
0
|
0.5
|
1
|
2
|
3
|
4
|
5
|
6
|
7
|
8
|
9
|
10
|
11
|
12
|
|
|
4/5
|
500
|
150
|
60
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
5/6
|
350
|
100
|
50
|
25
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
6/7
|
225
|
80
|
40
|
25
|
10
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
7/8
|
175
|
80
|
35
|
20
|
10
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
8/9
|
125
|
60
|
35
|
15
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
9/10
|
100
|
-
|
25
|
15
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
10/11
|
75
|
-
|
20
|
15
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
11/12
|
65
|
-
|
20
|
12
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
12/14
|
50
|
-
|
15
|
10
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
14/16
|
35
|
-
|
-
|
10
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
16/18
|
25
|
-
|
-
|
10
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
18/20
|
25
|
-
|
-
|
10
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
-
|
|
20/24
|
-
|
-
|
-
|
8
|
6
|
-
|
4
|
-
|
-
|
-
|
-
|
-
|
-
|
1
|
|
24/30
|
-
|
-
|
-
|
-
|
-
|
-
|
4
|
-
|
-
|
-
|
-
|
-
|
-
|
1
|
|
30/up
|
-
|
-
|
-
|
-
|
-
|
-
|
3
|
-
|
-
|
-
|
-
|
-
|
-
|
1
|
Consumer Horticulture | Bulletin 41: Narcissus