This canal, it appears, was twice surveyed under his direction by his son.

He did, however, succeed in his own time in opening up the navigation of the Avon, and was the first to carry barges upon its waters from Tewkesbury to Stratford.
The improvement of agriculture, too, had a share of Yarranton's attention.

He saw the soil exhausted by long tillage and constantly repeated crops of rye, and he urged that the land should have rest or at least rotation of crop.

With this object he introduced clover-seed, and supplied it largely to the farmers of the western counties, who found their land doubled in value by the new method of husbandry, and it shortly became adopted throughout the country.

Seeing how commerce was retarded by the small accommodation provided for shipping at the then principal ports, Yarranton next made surveys and planned docks for the city of London; but though he zealously advocated the subject, he found few supporters, and his plans proved fruitless.