Overwintering Hardy + Tender PlantsMany plants face hardship each winter when battling with cool temperatures and frost. To give your annuals the best chance at survival (and protect your investment), become familiar with how resilient your plants are, and which temperatures they can survive by pinpointing their hardiness. Hardy plants can withstand most winter conditions. This includes pansies, peonies, foxgloves, chrysanthemums, and calendulas. These flowers cope well with a bit of frost down to 23 degrees Fahrenheit. Because they can handle a slight freeze, hardy annuals are good choices for early fall and late spring planting. However, sustained freezing temperatures or a really good dip in mercury will do them in if they are not protected.
Half-hardy plants can survive a couple encounters with chilly night temperatures (35 - 45 degrees Fahrenheit) and light frost, but anything colder will cause their demise without some type of shelter.
Most tender plants are actually tropical perennials. Tender annuals include begonias, impatiens and zinnia.
Plants in this category can’t handle anything colder than 55 degrees Fahrenheit.