Marshalls said it had a long-term strategy to support landscaping and horticulture students. The partnership would help plug a worrying skills gap.
Sparsholt principal Tim Jackson said: "It is disappointing to tell some employers we have no more completing students to fill their vacancies.
"We hope this will encourage young and not-so-young people to consider a career in landscape and design where there are well-paid roles but a shortage of new entrants."
Marshalls will support his teaching team, provide masterclasses, supply landscape materials and give links to its register to help students develop their professional careers.
It will also provide teaching materials such as specifications, drawings and videos and invite students to factory and production facilities.
Marshalls Register operations manager David Jessop said: "There is a shortage of skilled new entrants to the landscaping sector, but demand for their services is higher than ever before."