WOOSTER, Ohio -- The crabapple trees in Secrest Arboretum are starting to bloom and should peak this weekend. The arboretum, part of the Ohio Agricultural Research and Development Centerâs Wooster campus, is home to more than 600 crabapple trees (Malus sp.) of more than 200 different types. Comprising one of the largest crabapple collections in the country, the trees are used by OARDC scientists for continuing research on aesthetics, disease resistance and adaptability to Ohio growing conditions. Gardeners, landscapers and nursery operators use the findings to choose which crabapple varieties to plant -- types that have specific traits (such as form and flower and fruit color), are easy to care for, and need few or no pesticides to stay healthy. Warm weather last week caused many of the treesâ buds to âbreak,â or start to open, said Arboretum Curator Ken Cochran. But recent cooler temperatures have slowed the process. âThe coolness will bring the blossoms out slowly,â Cochran said. âMost of the trees will be in full bloom this weekend.â The crabapple is one of Americaâs most popular and widely grown landscape trees. OARDCâs Wooster campus is at 1680 Madison Ave., just south of U.S. 30. Admission is free and open to the public seven days a week, dawn to dusk. To get to the arboretum, come in the main campus entrance (which is lined with crabapples of the âWhite Angelâ variety) at the brick time-and-temperature sign, turn left on Payne Drive, then turn right on Williams Road. Follow Williams into the arboretum. Williams curves right and turns into Green Drive; most of the crabapples are along these two roads. For more information, call the arboretum office at (330) 263-3761. Ahead for the arboretum is Plant Discovery Day --Â a sale and two auctions of rare and unusual plants, plus plant-related educational activities -- on Saturday, May 4, 9:30 a.m. to 3 p.m. Fisher Auditorium on OARDCâs Wooster campus is the location. Admission is free and open to the public.