PRODUCTION OF TULIP BULBS. - 15 
in leaving the flowers as long as they are in good condition. There 
is the further advantage to the grower that he is able to true up his 
St OC K 
WHEN TULIPS ARE RIPE. 
Generally speaking, tulips are ready to dig as soon as the tops 
have dried down in June. The precise time when they should be 
lifted, however, will depend somewhat upon the variety and varies 
slightly with the season. In the single early varieties it is not 
necessary to wait until the tops are dry. When they have yellowed 
well and the upper leaf has dried, most of the varieties may be lifted. 
The color of the outer coats is a good criterion. The bulbs should 
be dug as soon as the outer coats have turned to the rich brown so 
characteristic of the tulip. The sooner they are dug after maturity 
the better the coats are preserved. As a rule, tulips should be lifted 
just as soon as possible after the proper time comes, and this is 
especially true of the single earlies and Darwins. The experience 
of the Bureau of Plant Industry with single late forms, such as the 
Gesnerianas and Picotees, is that they are sometimes not ready to 
dig for a week or more after the tops die down. Often the bulb 
coats are perfectly white at the time the tops dry. This is especially 
noticeable if the soil is poorly aerated. The one important considera- 
tion as regards the time of digging is to do the work at the time 
when the coats will be best preserved. This means digging early. 
It means digging as soon as the plants are far enough advanced for 
the coats to be perfectly formed and to assume their normal color 
upon drying. If digging is long delayed, the coats deteriorate and 
the bulbs lose this natural protective covering. Often bulbs go 
into the bulb house with half of the coats white. If the soils were 
sandy loam, the coats would form earlier and be stronger. 
The moisture, heat, depth of planting, and nature of the soil all 
affect the maturity and coloration of the coats. With lack of mois- 
ture they dry off quickly and mature. Heat has about the same 
effect. In sandy soil the coats form and brown up better than in 
heavier loams. If the bulbs are planted shallow on heavier soils, 
the coats will brown up quicker and the plants be ready to dig earlier 
than when planted deeper. 
DIGGING TULIPS. 
Plate IX, Figure 1, gives a better idea of the operation of digging 
than a long description. The men work on their knees and take 
out the bulbs with a small short-handled spade. (PL X, Fig. 4.) 
The operation of digging tulips and other bulbous stocks, while 
very simple, is one which is capable of being highly developed. 
The good digger is active, quick, and alert in his movements. He 
operates his digging tool with a positive movement. He fixes in 
