ASTER WILT AND WILT RESISTANCE 
The so-called wilt disease of Asters is caused by a specific parasitic fungus, which 
may attack the plant at any stage in its growth from the seedling to the seed- 
producing age. The spores of the fungus may be carried on Aster seed and on 
inert matter with the seed, on the implements used in preparing the soil, and in 
the soil itself. When once introduced into the soil, it persists indefinitely and 
makes the land “aster sick,” that is, whenever an ordinary strain of Asters is 
planted into that particular soil at any time thereafter, the wilt fungus living in 
it will attack the plants and they will die off at some stage of their growth. 
A wilt resistant strain of Asters, however, is one which, although planted on the 
very sickest soil available, will withstand the attacks of the fungus and develop 
into strong, healthy plants. Just as some people or animals withstand the attacks 
of certain diseases, while others become sick at the first sign of an epidemic, so the 
resistant strains of Asters will withstand the attack of the wilt fungus, while the 
non-resistant strains will succumb. 
See our Bulletin No. 2, Asters of Today, for full details on Aster diseases and 
culture. 
Symbols used: 
a—annual 
b—biennial 
c—climber 
’—cut flower variety, special for florists 
gr—greenhouse plant 
p—perennial 
ra—rock plant annual 
rp—rock plant perennial 
Comparative Zinnia Flower Types 
No. 322—ELECTRO $2.90 
31 
