One indication of poor drainage in your garden is if your garden has puddles standing for hours after a shower of rain.
Achieving better garden drainage can be easy depending on the cause.
If you have had building work undertaken in the garden (maybe you’ve had a new garage built or you live in a new house) and heavy machinery has been used it may be that your soil is compacted. To cure this can be as simple as using a shovel and a lot of work. You should start by adding organic matter, such as chipped bark, compost or rotted manure, this opens spaces in the soil and allows water to percolate downward faster. Spread a thick layer of the material on the surface and then, working backwards, dig it into the ground to a depth of two shovels. Once this has been done you may also want to consider raising the soil level and creating slopes and shallow ditches to help channel the water away from the garden into a soak away (a pit in the garden filled with gravel). Once you have succeeded in loosening your soil you should try to keep it that way. Avoid stepping into your garden beds, and never dig when the soil is wet; both actions squeeze the air out of the soil and close the gaps. Adding a layer of organic mulch (compost, bark chippings or cocoa shells for example) on the surface at least once a year adds soil-building humus and helps feed earthworms that tunnel to aerate the soil.
Of course, it may be that just digging the garden over does not help, in this case you will need to consider installing new drainage to take the water away into the sewers. There are a wide range of both plastic drainage pipes and clay drainage products that can be used, both as land drains and also as waste water drains to take the excess water away to the main drainage system. Their range of drainage products cover both the DIYer, Selfbuilder and building contractor.
You may want to do any garden drainage work as part of a new design or redesign of your garden, this would possibly save time if you are planning a new garden and even save money by having the work done at the same time. It may even be that you want to improve your garden drainage as you live in a flood risk area and want to help protect your property from flooding.