They are not to be confused with a shovel.
Shovels generally have broad scooped blades which are better suited to moving loose materials, whereas, spades tend to be flatter, and stiffer, so that they can be pushed into the soil.
A spade is absolutely indispensable so buy the best you can afford!
Size and weight are of great importance!
Always remember that when it has a clod of soil on it, it will be much heavier.
For example, an expert may appear to wield a heavy spade with ease, but that same spade in the hands of an inexperienced gardener, or someone of small stature, might not be so easy!
If possible have a word with fellow gardeners beforehand, or better still, try their spade out in the garden and in this way you will have a better idea as to what is heavy.
These come in various lengths and sometimes ergonomic shapes to suit the height of the user, so select one suited to your build.
They can be made of wood, metal or synthetic materials, the choice is yours but the writer would suggest wood.
The reason for this is that metal ones are made from hollow tube and can rust from the inside, particularly around the area where they are riveted to the spade head.
This rust can, in time, cause total failure of the joint.
Synthetic varieties can be less rigid, which can sometimes pose a problem in say very heavy ground, or areas that have never been cultivated before.
Wood on the other hand has lasted the test of time.
The choice is yours, select the type you feel most comfortable with.
This may be made of a different material to the shaft, e.g. plastic handle on a wooden/metal shaft.
Check that the connecting rivets are smoothed to avoid injuring ones hands.
Some types have a Tee grip others a Dee grip, choose the one that feels the most comfortable.
This is possibly the most important part of the spade.
Ideally it should be made out of one piece of metal i.e. not one where the ferrule is riveted to the blade.
The riveted method of construction can have inherent weaknesses.
Soil will stick to some types of blades more than others making the task of digging more arduous, this can generally be put down to what the blade is made of, e.g. untreated steel or stainless steel.
With the untreated steel blade there is the possibility of it rusting when not in use, and this rusting can cause soil to adhere to the blade, whereas this is less likely with stainless steel blade thus resulting in easier digging!
Some spades are now surface treated to reduce the possibility of soil sticking to it.
Initially this works quite well, but after a number of years, this coating can wear off,and you end up effectively with an untreated steel blade.
Some blades will have a flat tread at the top of it to assist the digger to get more purchase when sinking the blade into the soil where others don't.
Some would say that in certain circumstance the tread can be a hindrance, meaning in such a case it is up to personal choice as to which one to select.
The sharpness of blade can be a selling point as this makes penetration into the soil easier.
This is a diminutive version of the standard garden spade and this makes it a handy tool for digging in constricted areas such as between perrenial plants in the border, hence its name.
It is sometimes referred to as a Lady's Spade.
Always clean the blade and handle after use.
A handle caked in soil is a potential source of blisters, and a dirty blade hinders every thrust.