
Grass varieties differ greatly depending on their origin. Grass seeds planted in lawns today have benefited from years of genetic research to produce the optimal seeds for specific climates and weather conditions. You can split grass types into two main categories: microtherms and macrotherms.
Microtherms grasses
In the UK, northern Europe and cooler parts of America, microtherms grass types are a better choice because of the colder summer months. They cannot withstand the high temperatures and drought of long periods of hot weather. Microtherms grasses tend to have lower heights and shallower roots than warm season grasses. Since they grow in climates where water is usually abundant, they don’t need deep root systems.
Key features
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Evolved to tolerate shorter daylight hours and lower temperatures
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When well looked after, they stay green all year round
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Sow in autumn when the soil temperature is still warm enough for germination without the stress of hot, dry summer days
Some examples of microtherms grass are perennial ryegrass, Kentucky bluegrass and tall fescue.
Macrotherms grasses
In southern Europe and hotter parts of America, macrotherms grasses thrive because of the absence of a cold winter, enjoying a growing season that lasts nearly all year long. Part of their success is that they have longer roots, which allows them to draw water from the soil at great depths, requiring less irrigation and withstanding longer periods of heat and drought.
Key features
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These grasses go into dormancy under 15°C and change from green to blonde
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Best planted as a single species to get a smooth, carpeted effect for your lawn
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Sow in spring when the soil is moist and the weather is warm
Some examples of macrotherms grass are bahia grass, Saint Augustine grass and zoysia grass.

Sand, clay or silt? Read on to discover which type of soil you have in your garden, and how to manage it for healthy plant growth.