Taking stock of cold, awaiting spring

Wednesday, January 27, 2010

The effects of the 10-day blast of cold air are showing up throughout South Florida, including our tropical garden. Yellow and brown leaves are revealing how sensitive tropical plants can be to to four days of below 40-degree temperatures, especially after very warm days in November and December.

Fairchild explorers took a close
look at cold damage in the

The rainforest understory was hard hit, with heliconias, gingers and many plants in the aroid family, such as small philodendrons, showing their dislike of chilling wind and cold.  It has been many years since the thermometer plunged that low for such an extended period.

More than 500 plants are showing some damage. Marilyn Griffiths, the garden's plant recorder, is documenting the damage, and the data will be used to follow these plants in the future. Heliconias are being cut and they will sprout back in the spring. Many palms are showing damage to their lower fronds, with some palms gradually dropping them. Senior horticulturist Mary Collins said some palms will not show damage until warm weather returns and they push out new spears that could display some distortion.

Leaves on shrubs and tropical trees that have been scorched brown are being left alone in case there is another cold snap. They can protect other leaves. Pruning now will encourage new leaves to sprout. New, tender growth is always the most susceptible to cold damage.

At the Fairchild Farm, Richard Campbell reports that the avocados and mangos did just fine, but the jackfruit and mamey sapotes were badly damaged. The ground actually got colder than the air, he said, and so the trees were hurt through the roots and from the ground up.

But fear not, most of the garden’s plants will come back as the weather warms up. In the meantime, our staff horticulturists are carefully monitoring plants for signs of fungus or bacterial disease.