Croton Hardiness and Tips for Enduring a Cold Spell

Most people grow Crotons outside in the landscape south of Tampa to Orlando, and east to Melbourne. Our Nursery is located just south of Central Florida on the Treasure Coast in Vero Beach. Most winters can get quite cool (occasional lows of 34  degrees) with a sporadic bout of frost/ freezing temperatures. This will not usually bother old, well-established crotons which have survived since the 1950’s and 1960’s.  

Since Crotons are Tropical Plants (not sub-tropical) they cannot tolerate cold spells, or extended ones—when the temperature drops down to 32  or lower—so we must add protection, and in particular for young plants.   In fact, when customers who know it gets chilly where the crotons are going to live in the wintertime buy plants from us at Fall Plant Sales, many times we’ll advise keeping the plants in pots in a protected place until the Spring growing season of the following year, and to wait until then to plant them outside in the ground.

A Frost Advisory is issued when the predicted temperature is expected to fall to 36 degrees or lower in the next 3 to 30 hours. Temperatures in the 35 to 40 degree range would also dictate a frost advisory.

A Freeze Warning is issued when there is an 80% or greater chance that the temperatures are expected to fall to 32 degrees (F) or lower in the next 3 to 30 hours.

If the temperature is expected to fall below 28 degrees (F) it is considered a Hard Freeze.

• In the event of Wind-chill temperatures expected in the mid-30 degree range and below, crotons must be protected and, crotons always need to be sheltered from a cold North wind.

• If the plant is outdoors and lives in a container which can be moved into a shed/garage, we suggest doing so as long as the temperature inside the structure will hover in the high 30’s to low 40’s, and be protected from the wind.

• If an outdoor container is too large/heavy to be moved, or if the plant is in the ground, they must be covered amply with Frost Cloth or medium- weight blankets from the thrift store.

• If or when a Frost Advisory or Freeze Warning for the overnight period has been, or is expected to be issued, we suggest you plan on covering the plants—or sort of ‘tenting’ them--under the covers. Do this during the warmest predicted temp. of the day (normally around 3 p.m. but not always, notably when a Cold Front moves through) so that the warmest air of the day is ‘captured’ and stays ‘trapped’ around the plant overnight.

•  When temps. are expected to plummet it also helps if, during the warmest temps of the day, you water the plants at ground level: Just the soil/root portion, but not the leaves and stems.

• An old wives’ tale states that the hardiest crotons are the green & yellow varieties.

• The skinny-leafed varieties, namely Picasso’s Paintbrush and Zanzibar are the most sensitive to being cold damaged.  Keep them in containers and bring them inside when evening temperatures dip down into the mid-40’s or below.

• If you live in Key West it’s okay to plant Picasso’s Paintbrush and other thin-leafed varieties in the ground, just make sure they will be protected from the ferocious winter winds that whip from one side of the island to the other.

• The first sign of cold damage is defoliation, but that does not necessarily mean the plant is dead. The bare sticks often surprise and delight their owners with new growth in the spring.

Thousands of crotons are shipped to all 50 states for Florists and Garden Centers. Several cultivars were originally bred in Europe specifically for the interiorscape market, and will perform very well in a house or office all winter long.  Ironically, these same crotons do not do well in air-conditioned environments for extended periods and are therefore not recommended in Florida as year-round house plants.