I want my Budew to evolve before lv. 17 so it can learn leech seed.
Budew evolves at max happiness in the daytime. To get him at max happiness feed it poffins it likes. There is a poffin house in Hearthome City. Also give it massages. The massage girl is in a house in Vielstone city.
Ev berries can be obtained from a berry scientist in Pastoria city. Use a poketch up which you can get from the berry master's house just outside of hearthome city.
Here is a list of berries and what they do :)
Hope I helped :)