From the archives of The Cut Flower Quarterly

Nerine

Nerine costs from .40 cents to $2.00 each, depending on the species. I would suggest bowdenii (a pink flower) which is the cheapest and a little easier. The sarniensis hybrids bring a wider color selection, ruffled petals and different bloom times along with a higher cost The crop time is 5-6 months, with .9 stems per bulb and a wholesale stem price of fifty cents to a dollar. This may not look appealing, but the good news is, the bulbs last many years. You can plant 25 bulbs per square foot and you will be rewarded with 6-8 new daughter bulbs each year. They also have an incredibly long vase life.            

Nerine bowdenii should be planted in March or April. However, know what species or cultivar you have! Is it from the summer or winter rainfall areas of South Africa? You need to purchase at least a 12/14 cm-size bulb because a smaller bulb will not bloom reliably that year. Plant 20-25 bulbs per square foot, with the neck of the bulb just rising above the soil. (I’ve heard some people suggest only 12 bulbs per square foot).  We tried planting only 9 bulbs per square foot and it was a disaster. First of all, only 60% of the bulbs bloomed, and the stems were shorter – about 12”. The following year we packed them in almost bulb to bulb and cut about .9 stems per bulb. The stem length was also improved to 20” and, upon drying them out, we found more daughter bulbs.                            

I had an interesting conversation with another grower regarding bulbs per square foot. We concluded that if the bulbs were not “stressed” and crowded they felt no need to reproduce. This is where we get into the sexual psychology of the bulb. You have to crowd the bulbs – get them to touch and feel how close they are to each other. The close proximity fools the mother bulb into thinking it will perish. In response, the bulb will flower to keep its species alive.                    

We prefer to use plastic bulb crates and plant 54 nerines per crate. The only disadvantage to this is that nerines have a long cropping period and you end up waiting for the last few flowers to bloom before pulling the crate. We also use a couple of other methods to save on bench space. The first is planting 1 bulb per 4” pot and cutting the flowers or selling them as a blooming potted plant.  We can then immediately free up bench space by pulling the pots off as they bloom.                 

The second is to plant the bulbs in crates outside, two weeks before the last frost.  They will sprout 2-3 weeks later, and a light frost will not harm them. This way they can grow outside all summer in a shaded corner until you need to bring them in before it snows. Just keep them as cool as possible all summer. After planting the bulbs, water them in and then hold back on more water until leaf development starts. At this point, until flowering, keep them evenly moist and use a medium rate of fertilization.                    

Night temperatures should be in the 50-60 degree range, and as the temperatures rise in the summer, use shade cloth and/or place them near the pad in a greenhouse. Try to keep day temperatures below 70 degrees.                

The leaves may start yellowing before and during flowering. This is normal and signals the imminent flower stalk and upcoming dormant period during the winter. Cut the flower stalk when one of the flowers is completely open and the others are beginning to crack.  The flowers will last up to 3 weeks with just normal preservative. After flowering (late August through October), start to withhold water and let the leaves continue to die down. They can be pulled two weeks after flowering if you need the space. We usually move all the crates about 3-4 weeks after flowering and stack them in a corner of the greenhouse to let the leaves finish dying down. Let the bulbs dry out over the winter in a cool 40-50 degree room or greenhouse.                                

We’ve also noticed there were more daughter bulbs if the crates or pots are left undisturbed for two years. After one year there would be 4-6 daughter bulbs. If left undisturbed in the crates for two years there would be 12-15 daughter bulbs. Our record was 22, with many having 18. The other side of this is the flowering. Some people say disturbing the bulbs every year cause them to decrease the number of flowers. We haven’t noticed any drop by digging up the bulbs each year – just fewer daughter bulbs. You should get an average of almost 1 flower stem per bulb.                            

There are literally no pests or diseases that bother nerines. Propagation is from bulb offsets from the mother bulb. These will then require two years before they flower. They are also very easy from fresh seed.  Let some flowers bloom out and they will readily produce seed. Many seeds will actually start growing tiny leaves before they have dropped to the ground from the seed pods. Just sprinkle the seeds on the surface of the soil and keep moist at all times. They will start growing within two weeks and will slowly pull themselves under the soil surface. The bloom time from seed will require three years of growth.

Ornithogalum

There are many different species of Ornithogalum, but one of the best and rarely grown is 0. arabicum.  The crop times are 2 months shorter and the bulbs are cheaper, but the stem price is not as high as nerine. It is also very easy to manipulate the cropping times for blooms from Easter through the summer.                                

Ornithogalum arabicum can be planted from October through May. The best flowers are produced from an earlier planting, however, the crop time is longer. A November planting will bloom in March and a February planting will flower in May. Plant 8-9 bulbs per square foot or 20 per crate, and cover them with 1” of soil. These are naturally large bulbs, in the 14-15 cm range, so you will need to make sure they are covered properly. Water them in and then only lightly thereafter until growth begins. During the first month use a 20-10-20 fertilizer at 250 ppm. In the following weeks up until flowering, switch to 200 ppm of calcium nitrate. This produces strong and tall stems. This a great crop for the cool greenhouse as a 50 degree night temperature produces excellent flowers.                

Crop time can be increased by two weeks through raising the night temperature to 60 degrees if needed. When planting in May, try to keep temperature below 60, and the day temperature below 75. This and the use of shade cloth is VERY important if you are trying to produce ornithogalum in the summer. Otherwise, you will be the proud grower of a short, spindly and small-flowered ornithogalum. You will need to put up one row of support netting.                        

If you’re shipping the flowers, cut them when the numerous flower buds swell up and turn completely white. If they’re for the local market, it’s best to let a few of the flowers open up. They have a wonderful licorice scent that is very pleasing. Flowers last 2-3 weeks with normal preservative.  The use of STS does seem to help. You should get 1 premium 24-36” stem, and sometimes a shorter and secondary stem, for an average of about 1.3 stems per bulb.                    

The only pest to bother ornithogalum is an occasional aphid, but this is rare. If you have aphids in your greenhouse, they would rather attack another plant before they had to settle for 0. arabicum. WARNING! Aphids do love another ornithogalum, 0. thyrsoides, better known as chincherinchee.         

They are not bothered by any major diseases and the only problems would be a soft rot if the bulbs are stored improperly during the dormant period. Store them in open plastic bulb crates at 40-50 degrees with good air circulation.        

Propagation is from offsets which require 1-2 years of growth, or from seed which requires three years. They are very easy from seed if it is fresh from the seed pods and will germinate in two weeks. Sprinkle it on the soil surface just like a nerine.                                

One last thought to keep in mind with nerine and ornithogalum is that they ship well, and your bunch price can take a drop if it’s flushing heavy somewhere else.  New Zealand produces thousands of nerines, but luckily they crop in the spring.  Holland, however, crops about the same as us and can really ruin that market.  Ornithogalum are produced mainly in California, but a local greenhouse crop will always have a little advantage due to increased stem length and being able to cut the flower in the open stage.

Nerine – Perhaps named for the sea nymph Nerine, in allusion to the fact that bulbs of the Guernsey lily (N. sarniensis), were cast on to that shore after a shipwreck. However, it appears that bulbs were actually brought from South Africa and given to John de Saumarez, Dean of Guernsey, about 1655 by sailors whose ship came to the island.                      

Ornithogalum – from the Greek “ornis”, a bird; “gala”, milk,  referring to the usually white flowers. The bulbs of Star of Bethlehem (O. umbellatum) were supposed by some to have been the “dove’s dung” of the Bible of which a “cab” measure was sold for a shekel during the Babylonian siege of Jerusalem.  “There was a great famine in Samaria. Behold, they besieged it, until a donkey’s head was sold for eighty pieces of silver, and the fourth part of a cab of dove’s dung for five pieces of silver.”  2 Kings 6:25

From Stearn’s Dictionary of Plant Names, 1996, William T. Stearn, via Allan Armitage