Some weeds live more than two years and are called perennials, such as many grasses, dock, Canada thistle, poison ivy, passion-flower, horse-nettle, etc. The best thing to do with them is to dig them out and take them away. Crude sulphuric acid applied to the soil kills them, or they may be starved by covering them with boards or with layers of straw. If they come up through the straw, lift it up a bit and let it fall again. There is yet another method, and if you have the time and land to spare, you will find it a good one. Smother them out by a dense growth of useful plants. Some use buckwheat and others cowpeas. The cowpeas are to be preferred as they enrich the soil by the nitrogen their roots gather. And that is another story that has its own time and place. Just now we are considering weeds, and you will find that they will keep you considering most of the time, for the only good thing so far known about them is, that they make even lazy farmers till their crops, if they have any. Left to themselves, weeds shade the crops, steal their nourishment, waste moisture, and probably poison the soil. Not even a mortgage can eat up a farmer’s profits like weeds. CHAPTER X. INSECTS AND DISEASES. The wise gardener uses the spray to prevent disease and the attacks of insects, instead of waiting to fight them after they have arrived. But if they attack your garden you must fight them intelligently and without ceasing. The destruction by insects, is, generally speaking, easily seen, but diseases of plants are not so plain, and have only been carefully studied even by experts during the past fifty years. At present, all we know is how to fight insects and diseases by different substances, put on or about the plants. As fresh discoveries are constantly being made, we will some day get rid of all these difficulties. It is always better to get the advice of an expert when insects or diseases become troublesome. Anything in the soil or surroundings of your garden which interferes with the plants during the growing season, weakens the crop and lays it open to attacks. Plants are like children. If they are badly fed, poorly clothed, ill housed or neglected, they are far more likely to become diseased than if they are kept in a good state. So look after your drainage, the character of the soil and the sort of cultivation you give it. All these help the crop to withstand disease. On the big western wheat fields, it has been found that drainage has a most marked effect upon blights, wilts and rust. Undrained wheat sections suffer greatly from rust.