168 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER 
5 Febrnary 27, 1890. 
questionable fragrance in their fronds, surpassing both in quality 
and degree that of the Drynaria. Lastrea or Nephrodium fragrans 
(noted on page 175) is one of the most remarkable of these, and 
it was the first “ Fragrant Fern ” that I knew. Some years 
ago an experienced Fern grower in the north of England 
called my attention to its Violet-like odour, and at the time I 
thought it was a practical joke, so strong was the fragrance, it 
seemed scarcely credible a Fern could produce it. T wo British 
Ferns, Nephrodium semulum and N. montanum, also possess a 
marked fragrance in their fronds, the former partakirg of the fresh 
hay character distinguishing the Drynaria. Some other Polypodiums 
have been observed that are entitled to rank with “ Fragrant Ferns,” 
such as P. normale and P. phymatodes, but in few is it so distinct 
as in N. fragrans. 
A considerable difference of opinion exists respecting the assist¬ 
ance a gardener can derive from a knowledge of the conditions 
under which a plant flourishes in its native state. It is con¬ 
tended that under cultivation plants are necessarily treated so 
artificially that it is practically impossible to reproduce exactly 
what they are supposed to require. Further, it is maintained that 
plants are often found growing in places that are not best suited 
for them, but which they are forced to occupy by being “ crowded 
out” in the “ struggle for existence.” Much of this is undoubtedly 
true, but it is also equally the fact that a knowledge of the habitat 
of a newly introduced plant is a considerable help to a cultivator, 
and many who have to deal with such could testify to the cor¬ 
rectness of this view. It is frequently deplored that collectors fur¬ 
nish too little information on this score, though they could always do 
so without revealing any trade secrets with regard to the localities 
where scarce or valuable plants are found. A man may possibly succeed 
in growing a plant well though he has no knowledge of its native 
climate or surroundings, but he is much more likely to do so if he 
be in possession of a few facts. The innumerable failures with 
Orchids when they were first cultivated were unquestionably due 
to the fact that the treatment was founded on imperfect know¬ 
ledge. Modifications have to be introduced in all cultural matters 
in accordance with the conveniences at command, but a general 
idea of the plant’s requirements is a useful guide in experimental 
culture.—L. C. 
TOMATO DISEASES, CAUSES AED 
PREVENTION. 
The roots of Tomato plants, under certain conditions, become 
in some cases almost covered with tuber-like knobs similar to those 
on the roots of Cucumbers. At one time I regarded this to be the 
work of an insect, but by careful observation, and noting the con¬ 
ditions under which it has appeared, have been compelled to draw 
other conclusions. Old soil, or soil that has been used for the 
same crop, has been carefully avoided, but this did not prove 
sufficient. Then the use of fresh manure was discontinued, but 
this it was found was not the cause, although it may be pointed out 
that fresh manure is the reverse of beneficial to these plants. 
Where this clubbed appearance of the roots takes place with us 
the strictest measures were taken to prevent it, but with no avail. 
The disease appeared in one bed only, two other narrow borders 
being occupied with Tomatoes'in the same house. Tomatoes were 
also grown in four or five other positions, with no sign of clubbing. 
Ultimately I came to the conclusion that the disease is mainly, if 
not wholly, due to a superabundance of bottom heat. I am also of 
opinion that the clubbing of the roots of Cucumbers is due to the 
same cause. None of the plants in the various houses had bottom 
heat, except in this one place where clubbing occurred. The bottom 
heat pipes were shut off under the two beds, which were formerly 
used for early Melons and propagating. At the back where the 
roots clubbed the top heat pipe was shut off, but the heat, backed 
up from the return and the pipe, was frequently very hot—too 
hot for the well-being of the plants—and resulted in the disease 
that has been pointed out. 
Place these plants in loose rich soil, or soil in which too much 
manure has been incorporated, so as to cause a soft sappy growth, 
and maintain a humid atmosphere for forty-eight hours, and the 
plants are attacked by Phytophthora (Peronospora) infestans. 
When the soil is firm and not too rich this fungus will appear if 
the temperature is low and the atmosphere becomes saturated, or 
nearly so, even for a very short time. This is not the only cause,- 
and another may be pointed out. How often are the plants 
divested of a good portion of their foliage and then given a soak¬ 
ing of water. We have been guilty of this, and know that it is- 
practised by many others. No greater mistake can be made, for 
it is almost certain to predispose robust plants to this disease. 
They are attacked in such a short time that the main cause may for 
a long time be overlooked. After thoroughly watering a house of 
Tomatoes the atmosphere for a time is often too moist, and if a 
good percentage of foliage has been removed it adds to the evil. 
If the borders in which they are growing have been dry the evil is 
increased. No fear of an attack from fungus need be anticipated 
if the temperature of the house is slightly increased for a time 
after watering, so as to assist in evaporating the superffuous mofs- 
ture. If the weather is warm and bright, this can be accomplished 
by ventilating on a more liberal scale, and watering during the 
early part of the day. The plants should be dressed two or three 
days previous to watering, or about the same time afterwards. This 
disease can be prevented by warmth, the atmosphere on the dry 
side, and judicious ventilation, combined with careful watering, and 
soil that will promote firm sturdy growth. 
When once the disease appears it can be stopped, and must be 
at once, for it soon communicates itself to healthy plants if the- 
treatment is not changed and a remedy applied at once. It is- 
surprising how quickly the whole tissues of the plant become 
diseased, and once it reaches this stage all remedies are hopeless^ 
nothing remains but to burn the plants. They never do any good, all 
new growth bec-imes diseased just when hopes are entertained of 
the plant recovering. The moment it shows itself all infested! 
leaves and any portions of the stems should be cut away at once 
and burnt, and the plants syringed with powdered sulphur and" 
water. For this purpose a 4-inch potful of sulphur will be ample 
for three or four gallons of water. This will destroy the fungus- 
and save the whole house of plants if other conditions are at once 
rendered favourable. Neglect for a few days may result in alP 
the plants having to be destroyed. 
Another and certain cause of this disease is excessive watering, 
which is easily remedied by care. It promotes soft growth, bad 
setting, and in the end disease. If Tomatoes are properly managed 
they do not require half the water that some think necessary for- 
their well-being. The less they have to be watered, as a rule, the 
better they succeed. In some positions and under certain conditions 
during hot dry weather the plants may have to be watered daily 
to keep them from suffering by drought. Where the conditions of 
the roots are such that this has to be done to maintain moisture 
about them, the best interests of the plants are sacrificed. The soil 
in which they are growing should never be destitute of moisture- 
from the time they are started until the whole of the crop has 
been gathered. If kept as near an intermediate condition a& 
possible so much the better without recourse to frequently water¬ 
ing them. They do not need much soil in which to grow, and if 
the surface is thoroughly mulched to prevent evaporation the 
plants will do all the better, and the roots continue to work freely 
from first to last. If grown in pots the advantage is on the side- 
of plunging ; they require less water, and in consequence afford 
a heavier crop of fine fruit. The plants that had the least 
water with us last year were the best, and the same fact was 
observable under the various conditions under which others were- 
grown. 
There is another fungus that attacks these plants, and which is- 
encouraged by a low stagnant atmosphere. Ten days or a 
fortnight is ample under certain conditions of culture for a whole 
house to be covered—leaves, stems, and fruit—with a brown mould. 
This gives to the foliage a dried up appearance, as if they were 
ripening prematurely. This is bad if allowed to spread unchecked, 
and will soon ruin the crop. But it is not such a serious disease as 
the former, that blotches the fruit, leaves, and stems at first as if 
they had been scorched. Directly this is observed the plants should 
be thoroughly syringed with the sulphur solution that has been 
pointed out, and the temperature slightly raised where this is- 
practicable, and it will be destroyed in a few days. 
All that is needed to guard against these diseases is a moderately 
warm rather dry atmosphere. A liberal circulation of air on all 
favourable occasions promotes firm sturdy growth. This is essential 
to success. Early Tomatoes, after they commence growing freely, 
are often kept too warm and too close, and are given twice the 
quantity of water that they really need. 
The soil must be firm and not too rich, the growth of moderate 
strength—that is, firm and short-jointed. Loose rich soil promotes 
undue luxuriance. It is possible to have the plants too strong 
to ensure their setting freely, even if such sappy examples of 
growth do not fall an early prey to disease. On the other hand 
