REGULAR readers will be aware that I keep banging on about the importance of soil, but there's no escaping the fact you can transform poor, thin ground into a healthy haven for plants over time. Many years ago, I had a sair fecht driving a fork more than 10 centimetres into my ground, but I can now feed the family all-year-round from the same spot.

It pays dividends to understand what makes the ground tick and the tools you’ll need, and with Christmas fast approaching it's an ideal time to compile a wish-list for Santa. Some ideas here are inexpensive, others less so, but they should all be part of a gardener’s tool kit.

Most British books describe methods and timing for warmer, sunnier gardens than ours, so I was pleased to come across a new title from Sweden. Good Soil by Tina Raman and friends (Frances Lincoln, £18.95) is a very approachable book designed for folk with little or no scientific training or knowledge, explaining fairly complex ideas very clearly.

The authors touch on topics we often know less about than we imagine, such as humus and how different soil types look and work. She also identifies what drives the nutrient cycles in the soil and shows how our actions affect them.

It's an up-to-date work too which includes passages on biochar, a combination of manure and charcoal which was uncovered by archaeologists studying how peoples in the Amazon created highly productive “black earth” from poor forest soils.

The authors make good use of sidebars to help explain this. They write: "The good storage properties of charcoal depend on its tiny structure. It’s like a sponge with a huge surface area, sucking up both water and nutrients to be dealt out at the right levels later on." Gardeners can now buy biochar or make their own by buying charcoal, grinding it down to 1cm fragments and soaking it in dilute urine and liquid feed such as nettle, comfrey or, if necessary, an organic fertiliser.

There’s lots more, including stunning photographs and detailed instructions on how and when to feed different ornamentals and edibles, but I confess I was riveted to a table outlining the NPK (nitrogen, phosphorous and potassium) content of different manures and how long the ground benefits from a dressing of different mucks.

My spring forays to a nearby field, filling an old onion bag with sheep goodies, were well worth it, soaking my treasure in a barrel of water to make the perfect feed. I could assure my old lab/collie cross there was more to sheep than providing an alluring shoulder perfume after a vigorous roll.

There’s every kind of compost, nutrient and fertiliser for the soil, but you first need to know what to buy. Start by using a pH kit to test the ground’s alkalinity or acidity. This shows which plants will thrive and whether you should modify the soil. Kits range from £7 to £15 and give a general indication. I find probes, priced from £10 to £20, are less reliable, especially if they also claim to record temperature and moisture.

More detailed kits also measure nitrogen, phosphorous and potassium, the elements controlling plant establishment, growth, flowering and fruiting. A Selfcontrol kit for £28 is a good option, and in my experience the Hanna Instruments kit, (£59, hannainstruments.co.uk) makes an invaluable present.

I find checking soil temperature is just as important for working out when to sow and plant besides for monitoring compost temperatures, showing how different materials affect the heat.

Simple steel probe compost thermometers are available at £9.95 from thermometerspecialist.co.uk. They also work well in the soil. Undoubtedly the deluxe version is ThermaData’s TD Data Logger, (£72, thermometer.co.uk), which records and downloads temperature fluctuations over 24 hours. My son gave it to me as a Christmas present a few years ago and now I wouldn’t be without it.