By Doug Van Vreede
In the Friends School Plant Sale we always offer compact dahlias, about the size of petunias. In most years we also offer dahlias that have bigger, bold, beautiful flowers, up to 10” across, on plants about 48” tall. These dahlias will really attract attention in your garden.
Dahlias come in many forms and colors: five of the forms are pictured at right. The American Dahlia Society website has an Online Classification Guide that explains the different forms of dahlia flowers. It also has links to other dahlia resources including the Minnesota Dahlia Society (MDS). Every year, MDS hosts a dahlia competition at the Minnesota State Fair.
If you have trouble with deer browsing your garden, dahlias are for you! Deer walk right past them. Some varieties are susceptible to Japanese beetles, though. Another “pest” to consider is wind and rain. When those large flowers open, the plant becomes top-heavy. Most dahlias need to be staked.
Dahlias don’t survive Minnesota winters. You can choose to either treat them as annuals and buy new ones each year or you can dig them up in the fall, store the tubers over winter, and replant them next year.
Wait until a week after the first frost before digging them up in fall. There are many techniques for overwintering dahlias. Search the internet or ask some local dahlia aficionados for advice. They are worth the effort!