Rain steadily washes lime out of your soil at an average rate of ½ oz per sq. yd. Slowly the land becomes more sour, and neither humus-makers nor the majority of fertilizers are of any help in correcting this condition. The answer is to apply lime – the oldest and still the best soil conditioner.
– Lime neutralizes sourness. Very few garden plants grow well under acid (sour) conditions.
– Lime brings life into your soil. When soils are sour, beneficial bacteria and earthworms tend to die out. Lime helps them to flourish.
– Lime breaks up heavy clay soil. Lime binds the tiny clay particles together into ‘crumbs’ and so makes heavy soils easier to work, warmer, and better draining. You can prove for yourself this property of lime. Add a teaspoonful of clayey soil to a glass of water and stir until it is all in suspension. When you stop stirring, the liquid will remain muddy because the minute particles of clay are not heavy enough to fall to the bottom of the glass. Not stir in a ¼-teaspoonful of hydrated lime. The clay particles group together into clearly visible soil crumbs, which quickly sink to the bottom of the tumbler.
– Lime is a plant food. Calcium, the main component of lime, is an essential nutrient for all plants.
– Lime makes other plant foods available. Lime acts on humus, setting free the elements needed for healthy plant growth.
– Lime discourages pests. Some soil diseases (club root, for example) are checked by liming. Soil pests such as slugs, leatherjackets and wireworms hate it.
How much to lime?
Your garden can have too much of a good thing. If an excessive amount of lime is used, humus breaks down too quickly and plant leaves turn yellow because of the lock up of iron in the soil. It is easy to avoid overliming by testing your soil and applying these rates.
When to lime?
The best time to add lime to the soil is after digging, in fall. If fall manuring has been carried out, postpone liming until February. Spread the powder evenly over the surface, leaving rain to carry it down into the soil.
Vegetable plot: Lime every 3 years. If you follow a crop rotation, lime the plot which is intended for the cabbage family. Do not lime land which is to be used for potatoes.
Flower garden: Lime every 2 years on sandy soils, and every 3 years on heavy soils and loam.
Remember that lime likes to be alone, so do not mix it with other soil dressings. To avoid the loss of plant foods, lime should not be applied until at least 2–3 months after manuring, and 1 month after fertilizers.
Manures, composts, fertilizers and seeds can safely be added to the soil one month after liming.