The hybrid amaryllis, Hippeastrum spp., is a tender bulb easily grown in pots. Amaryllis can be grown outdoors throughout the year in mild climates, but must be grown indoors in Nebraska except during the warm summer months. Amaryllis is prized for its huge showy flowers ranging from scarlet or crimson to white in color, and often striped or mottled. Most amaryllis are Dutch or African hybrids selected for flower size, color and ease of forcing. The usual flowering season is from February to April. The foliage grows during spring and summer, ripening early in the fall if temperatures are low and the soil is allowed to dry out. The bulb normally remains dormant until late winter (December or January).
The preferred soil mix for amaryllis is high in organic matter such as two parts of loam soil to one part of perlite to one part of well rotted manure. If manure is not available, another source of organic matter, such as peat, leaf mold, composted bark or wood or compost, may be used.
Five- to six-inch pots are suitable, but the best size depends on the size of the bulbs which vary considerably. A space of approximately 2 inches between the bulb and the edge of the pot is desirable. Bulbs are usually received early in the winter. They can be potted at once or stored in nearly dry sand until the end of January when growth normally begins. In potting, place the bulb so that only about half of it is below the soil, with the upper part (pointed end) left exposed. Press the soil firmly around the bulb and water thoroughly. Do not water again until the roots are well developed as overwatering can lead to bulb rots. Only when the roots have become well established will the plants need more frequent watering. The foliage is weakened by being forced too rapidly if temperatures are higher than 50 to 60 degrees Fahrenheit during the period before flowering.
After the flower bulb has emerged, an application of a balanced fertilizer at intervals of 10 days is helpful. A liquid or dry fertilizer can be applied and either inorganic or organic types are satisfactory for this plant. Be sure to read the label carefully so that you apply the correct amount of that particular fertilizer. Amaryllis will flower 6 to 8 weeks after growth is initiated.
When the flowers have withered, cut the stem off about two inches above the bulb. The growth is most active during the next two or three months and should be encouraged by ample water and fertilizer. When all danger of frost has passed, the plant may be plunged, pot and all, into the open ground in full sunlight, or it may be grown indoors in a bright location during the summer. Restrictions in growth during this period interfere with the proper development of the bulb in preparation for next spring's flowers. Gradually decrease watering late in summer when the leaves begin to turn yellow. Allow the soil to become completely dry when the foliage has died back. While in this dormant state, the bulb should be left in the pot and stored in a cool place, preferably at 40 to 45 degrees Fahrenheit. Turn the pot on its side and do not water during the dormant period.
Reflowering
Since it requires 6 to 8 weeks from the beginning of growth to the production of flowers in amaryllis, you can have an extended flowering period by selecting the time for growth initiation. Begin by starting growth in the first bulbs in January and continue through the latter part of March. Before applying water to the soil in the pot to start the growth, check the pot to see whether repotting is needed. Repotting is required if the bulb has increased so much in size that it is crowding the edge of the pot, or if offshoots have developed. After the bulb is removed from its pot, use a pointed stick to pick out as much of the soil as can be removed without damaging the roots. The bulb with some soil still adhering to its roots is set in a well-drained pot slightly larger than the old root bulb. Offsets or small bulbs should be taken off and potted in 3-inch pots. They will flower in two or three years. When the new leaves and flower spikes begin to show, the temperature may be increased to 75 degrees Fahrenheit. During bloom, cooler conditions will prolong the flowering period.
Propagation
Amaryllis can be propagated by seed, offsets or cuttage. Since seeds do not always produce plants similar to their parents, most named hybrids and selected strains are propagated by cuttage. Seed pods of amaryllis develop rapidly and are mature within 4 to 5 weeks after the flower has been pollinated. Pods should be picked as soon as they turn yellow and begin to break open. Seeds should be removed from the pod, allowed to dry for a few days and planted immediately. The seed bed should be partially shaded, and the media used for seed germination should be well drained. Following germination, increase the light until the plants are receiving full sunlight.
The bulbs may be cut vertically into as many as 60 pieces. Care should be taken that each piece has a portion of the stem tissue or basal plate of the bulb attached to the scales. The best time for cuttage, a propagation technique by means of cuttings, is from August to November. The wedges should be planted immediately in a mixture of peat and sand. Bulbs purchased from garden stores or florists usually flower at Christmas time. Theses bulbs have been specially treated by the grower to allow for this early flowering. After this initial flowering at Christmas time, the amaryllis will bloom later in the following years. Generally, the earliest flowering occurs in February. However, you should be able to flower them for the Easter season by initiating growth at the proper time.