Q 
PROTECTING PLANTS 183 
have been attacked by fungi should be raked up and 
burned, and in the fall all diseased wood should be cut 
out and destroyed. It is important that diseased plants 
are not thrown on the manure heap, to be distributed 
through the garden the following season. 
Practice a rotation or alternation of crops (p.114). Some 
of the diseases remain in the ¢ : 
soil and attack the plant year 
after year. Whenever any ” 
crop shows signs of root disease, or soil disease, it is partic- 
ularly important that another crop be grown on the place. 
See that the disease or insect is not bred on weeds or other 
plants that are botanically related to the crop you grow. 
If the wild mallow, or plant known to children as 
“cheeses” (Malva rotundifolia), is destroyed, there will 
be much less difficulty with 
hollyhock rust. Do not let 
the cabbage club-root disease 
breed on wild turnips and 
other mustards, or black- 
knot on plum sprouts and 
wild cherries, or tent-cater- 
pillars on wild cherries and 
other trees. 
” Always be ready to resort to 
hand-picking. We have 
a grown so accustomed to kill- 
219. A knapsack pump. ing insects by other means 
that we have almost forgotten that hand-picking is often 
the surest and sometimes even the most expeditious 
means of checking an invasion ina home garden. Many 
insects can be jarred off early in the morning. Egg- 
masses on leaves and stems may be removed. Cut- 
worms may be dug out. Diseased leaves may be picked 
