Soil Fertilizers
Unfortunately for him, the theory doesn't hold water. About the first week in June, hot weather comes on suddenly. Soil bacteria that have been all but dormant begin to multiply at an unbelievable rate. In a matter of two weeks, nitrogen is being released from the sludge-rich soil to the plants so rapidly that grass blades wilt and collapse. If a nitrogen test chemical is applied to the grass at this time, tiny beads of red will show up on every blade. This indicates that free nitrogen is being released-actually exuded from the blades-by a process known as guttation. This lawn is suffering from a far more serious nitrogen burn than lawn number one received in spring. About as close as the second lawn owner will come to knowing the real cause, however, will be his comment, "I guess my grass just couldn't stand summer heat."

Golf course greenskeepers are familiar with this problem. Because they must always maintain grass in top condition, they often have to push turf feeding close to capacity and risk bringing on guttation.

The moment they see traces of grass blade wilting or "flagging" they will apply test chemicals to see if nitrogen is coming out of the foliage. If it is, a crew of men is quickly assigned to wash (leach) the excess plant food out of the soil with liberal applications of water.

A paramount fact every gardener should fix in mind is that any excess of nitrogen beyond the needs of the plant will cause a burn. This burn may become visible very soon after the fertilizer is applied or, in the case of manures, the effect may be delayed many weeks.

Even certain organic products can cause rapid burn if used in excess. Dried blood, one of the most valuable sources of nutrients, is so readily soluble that it may work like a chemical fertilizer salt. The same is true, to a somewhat lesser degree, of fish emulsions and urine.

In the following source lists of fertilizers (and throughout the book) you will note that I almost invariably give technical names and discuss basic fertilizer materials rather than trade-named prod­ucts. Every ingredient can be found in a variety of trade-named "plant foods." Fancy names and pretty pictures on the fertilizer bag won't feed your plants. Read the legally required label of contents on the bag or box of each brand of fertilizer in the store. Buying accord­ing to actual content of ingredients is the only sure way of getting what you want, and need-and pay for.