5. List of Hyacinths for forcing. 
EARLIEST EARLY AE 
white 
Arentine Arendsen ditto 
L’INNOCENCE 3 ditto 
Edelweiss 5 
(Queen of the Whites 
blue 
BISMARCK ditto 
Dr. Lieber se 
Ostara F 
Myosotis 
Grand Maitre ditto 
Perle Brillante “3 
Duchess of Westminster a 
King of the Blues 
red Queen of the Blues 
Jan Bos dito ditto 
Rose and pink La Victoire <3 
PINK PEARL ditto ditto 
Lady Derby a 
Gertrude ditto 
Marconi 
yellow Queen of the Pink 
Yellow Hammer ditto 
Prince Henry 
City of Haarlem 
Special rules for Tulips 
1. When are the bulbs for earliest forcing to be brought into 
the greenhouse ? .; 
For an alphabetic and a descriptive list of all varieties we refer to 
the descriptive list of Tulips and Daffodils in this booklet. This list will 
also give you the dates at which the bulbs should be brought into the 
greenhouse. 
These dates can only be followed if the bulbs have been rooted under conditions 
outlined in the general rules. 
Needless to say that many unsatisfactory results experienced with 
early forcing, are caused by bringing in the stock too early and by 
applying too much or insufficient heat during a prolonged period. 
2. Treatment in the greenhouse. 
a. Early tulips (single and double) including Mendel tulips for early forcing. 
These tulips for earliest forcing have to be forced in a completely 
dark place at a steady temperature of 65 to 70 °F to draw them up. 
This is necessary in order to get a good length of stem. After this 
they can be taken to the bench and given a shaded situation at about 
65 °F. They will soon colour up and gain in substance. When they 
are in full bloom, keep them at 55 to 60 °F, to get full colouring. 
Bulbs brought in later, will not need the same drawing-up-treatment, 
as the sprouts will be longer by that time. They can be placed on the 
bench from the start, shaded with newspapers for a few days. After 
this they should be kept on the bench partly shaded. 
b. Late tulips (including Darwin and Treumph tulips.) 
The forcing varieties should be started off in a temperature of 55 
to 60 °F. A lower temperature delays flowering, a higher temperature 
gives weak stems and soft flowers. A dark or shaded place will be 
necessary till the first ring or joint is out of the bulb, after which they 
can be given more heat up to 70 °F. 
For tulips in flats it is advisable to remove the small side shoots 
which grow from the outside of the bulbs. 
3. Watering of early forcing tulips. 
The quantity of water and the time of watering plays an important 
part. As a rule too much water is given too frequently, especially when 
the plants are still short. Once a day and preferably in the morning 
so much water must be given as can be absorbed by the plants in 
24 hours. 
Definitely avoid splashing the water all over the foliage, particulary 
when the plants grow taller, and water only enough to moisten the 
soil properly. 
Never apply water when the sun shines on the plants. 
It is recommendable to use water of about the same temperature as 
prevails in the forcing house, thereby avoiding chilling the soil, bulbs 
and pots with cold water. 
4. Precooled bulbs. 
Precooled tulips are treated the same way as uncooled ones; how- 
ever, these stocks can be brought into the greenhouse a fortnight earlier, 
provided that the flowerbud has grown out of the bulb. 
For the first week give them a temperature not higher than 55 °F, 
let it rise gradually to 70 °F, till the plants begin to flower. 
Varieties suitable for precooling. 
The varieties mentioned below are some of the varieties which are 
most recommended for precooling. Many other varieties, however, are 
also suitable for precooling. 
Darwintulip Wm. Copland, Rose Copland and other Coplandsports. 
Darwintulip Wm. Pitt 
Darwintulip Red Pitt 
Cottagetulip Albino 
Cottagetulip Carrara 
Cottagetulip Golden Harvest 
