By Calvin Finch, Conservation Division, Manager, Water Resources & Conservation Dept., SAWS, and Horticulturist
TIME TO ASSESS FREEZE DAMAGE
Are you wondering how much damage the freezes in late February and March did to your landscape? Here are some observations and advice consistent with those observations for you to consider.
Woody plants in some neighborhoods sustained significant freeze damage. Citrus, hibiscus, oleanders, bougainvillea, mandevilla, Mexican heather, and plumeria, even if they were covered, were hit hard. In many cases, the leaves were just frozen but some will have stem damage.
The easiest way to determine how much of a particular plant is frozen is to wait for three or four weeks and see where it sprouts. Check to make sure the sprout is sturdy and that all the wood underneath is alive. Cut off the dead wood above the sprout.
A few woody shrubs, including dwarf pittosporum, are injured, but the damage will not be obvious until this summer. When it is 90 degrees F. dwarf pittosporum with freeze damage to the vascular system will make it impossible to support upper portions of the plant and stems will die, often in the middle of the plant.
Root hardy perennials probably lost their tops but will sprout from the roots. Dwarf ruellia, blue plumbago, lantanas, firebush, esperanza, poinciana, firespike, and summer salvias are in this category.
In the vegetable garden the potatoes and onions will probably resprout. Most of the greens, except spinach, were damaged. Prune off the freeze burnt areas. You still have time to replant radish, beets, rutabagas, and carrots.
The cool weather annuals lost most of their blooms in the freeze but, if the foliage survived, they should have a good bloom period in April. In most gardens petunias, calendulas, and ornamental kale show the most damage. Snapdragons, dianthus, and larkspur lost their bloom but the foliage escaped. Pansies and, surprisingly, cyclamen hardly seemed affected.
Iris also lost its open bloom but new blooms after the freeze did not seem affected. Fruit trees seeemed to be in the same situation. All open blooms were killed but the buds were unaffected. There is still the potential for a crop on trees in the city.
The freeze was a blessing for many lawns. Weeds like thistle and rescue grass froze, although henbit and dandelions were not phased. There is some speculation that St. Augustine lawns will have freeze damage, but I think most were hardened off enough to escape damage.
Resist the temptation to fertilize or overwater the lawn. Green up will not occur until we get two or three weeks of warm weather. The fertilizer is only useful after the grass roots and tops are active. The best rule is to fertilize after you mow real grass two times. That usually means May 1. Water every three weeks if it does not rain.