ording to
the temperatures at which they will germinate or sprout readily and
can be safely planted.

Class A. Those seeds that will germinate or sprout at an average
temperature of forty-five degrees in the shade, or at about the time
the peach and plum trees blossom:

Barley Beet Parsley
Oats Carrot Parsnip
Rye Cabbage Onion
Wheat Cauliflower Pea
Red Clover Endive Radish
Crimson Clover Kale Turnip
Grasses Lettuce Spinach

These can be planted with safety in the spring as soon as the ground
can be prepared, and some of them, if planted in the fall, live
through the winter.

Class B. Those seeds that will germinate or sprout at an average
temperature of sixty degrees in the shade, or when the apple trees
blossom:

Alfalfa Soy Bean Squash
Cow Pea Pole Bean Cucumber
Corn String Bean Pumpkin
Cotton Melon Tomato
Egg Plant Okra Pepper

We are now ready to answer the question: What conditions are necessary
for seeds to sprout or germinate? These conditions are:

The presence of enough moisture to keep the seed thoroughly soaked.

The presence of fresh air.

The presence of more or less heat.

This teaches us that when we plant seeds in the window box or in the
garden or on the farm we must so prepare the soil and so plant the
seeds that they will be able to obtain sufficient moisture, heat, and
air for sprouting. The moisture must be film water, for if it is free
water or capillary water filling the soil pores, there can be no
ventilation and, therefore, no sprouting.

SEED TESTING

In a previous experiment (page 73) the seeds planted in the wet clay
did not sprout (see Fig. 38). In answer to the question, "Why is
this?" some will say the seeds were bad. It often happens on the farm
that the seeds do not sprout well and the farmer accuses the seedsman
of selling him poor seed, but does not think that he himself may be
the cause of the failure by not putting the seeds under the proper
conditions for sprouting. How can we tell whether or not our seeds
will sprout if properly planted? We can test them by putting a number
of seeds from each package under proper conditions of moisture, heat
and air, as follows:

For large seeds take two plates