Alan Horgan of Certis was question master. Skye Maddox (Chichester), Mike Lall (Capel Manor), Adam Ward (Hadlow), Alex Christie (Merrist Wood) and Jon Collins (Berkshire College Agriculture) also competed.
Other regional finals are this week. Sponsors are Bulldog Tools and MorePeople.
Speaking about job prospects once they have completed their courses, Houston said: "Employers assume people do not have good practical gardening skills because they are straight out of college but we do a lot have."
Laucht said: "A lot of people assume qualifications will lead to fantastic wages but that's not the case."