Outdoor thermometers dipped to 32 degrees or below about 6:00 A.M. Saturday morning December 26, in many Central Florida areas. Residents further north outside Gainesville and in the Tallahassee area reported mid to upper 20's. Many of these later areas already saw cold damage in early December. Some damage in even lightly affected areas caused injured to coleus, pentas, gingers and many foliage plants. Tomato plantings and similar warm season edibles are not happy and likely eliminated by the cold. Only the weeks ahead can help determine the full extent of a few nights of these low temperatures.
Following are some cold weather plant survival tips form a seasoned Floridian who survived the devastating freezes of the 1970's and 1980's.
- If plants are damaged, wait to do the pruning. Most will die-back further than you think. The general rule is to 'do the pruning when you cannot stand the brown'.
- Water as you would normally. Extra water does not heal cold damaged portions.
- Keep feedings to the scheduled applications. Fertilizer cannot be used by plants until they begin new growth.
- Lawns may turn brown and some like zoysia and bahia go dormant. Give these and other turf types normal care for this time of the year. Resist fertilizing or over watering. Most lawns will recover when the warmer weather arrives. Don't expect new growth from zoysia or bahia lawns until March or April.
After a killing cold some plants may be frozen back to the ground but lower buds and roots often survive. It can take these plants months to begin growth. Give them at least the spring months to show signs of growth. I had a croton that did not regrow until summer. I had given up on it but it showed me how persistent plants can be.
More cold may be on the way as winter is no where near over. Her are the things you can still do to help your plants survive.
- Move very cold sensitive plants to a warm spot if you can - some include the pothos, aglaonemas, diffenbachia and ficus.
- Don't pick the citrus fruits unless the temperatures will be in the 26 to 28 degree range for several hours. What are you going to do with bushels of picked citrus? Most survive on the trees just fine and if they do freeze they can still be juiced for several weeks.
- Know what plants to protect - roses, ligustrum, viburnum and similar hardy plants will survive most cold snaps if you do nothing.
- If you cover plants use fabric-based materials and drape them to the ground. Plastic provides little if any protection.
- Some Christmas tree lights made for outdoor use give off heat and can be used as a heat source under covers. Push them within the plants so they do not touch the covers.
- Covers can be left on the plants if temperatures are below 60 degrees during the day except if you are using plastic.
- Turn off the sprinklers as most systems are not designed for cold protection.
- Browning of some lawns is likely due to cold; most will recover with normal care.
- Lawns can still make growth during the winter; continue to water and mow as needed.
- Once a week watering is the rule and normally adequate at this time of the year.
- Mow lawns to keep a uniform look; do not change blade height.
- Feeding time is over until late winter for lawns.
- Try regreening yellow lawns with an iron or minor nutrient application if needed.
- Many warm season weeds have turned brown; remove and resod these areas.
- Fill in bare spots with sod or plugs; delay seeding of permanent grass until spring.
- Ryegrass can be seeded to temporarily regreen brown turf or fill bare areas.
- Spot kill patches of persistent winter weeds with a selective herbicide for your lawn type.
- Frosts and freezes damaged sensitive plants; delay pruning until live plants portions are known.
- Winter is a good time to add hardy trees, shrubs and vines to the landscape.
- Florida Arbor Day is January 15 a good day for tree, shrub and ground cover plantings
- Make sure root balls are moist at planting time: add a berm to direct water through root balls.
- Winter through spring is our dry time; renew mulch layers to conserve moisture.
- Leaves are falling from trees and shrubs; use as mulch or add to the compost pile.
- January is a good time to begin yearly pruning of trees and shrubs.
- Trim dead or declining portions from trees and shrubs.
- Schedule major tree trimming now to be ready for severe 2021 weather.
- Crape myrtle grooming can begin this month; remove only the seed heads and small twigs.
- Remove dead fronds and old seed heads from palms but keep the good green leaves.
- Keep actively growing plants moist to remain green and attractive.
- Once a week watering or less is usually adequate for established deep-rooted plants.
- Replant declining flower beds and planters with hardy cool season selections.
- Container gardens are a good way to enjoy plants in the landscape.
- Add hanging baskets of color where they can be easily seen.
- Feed container gardens weekly if needed for growth; in ground annual plantings monthly.
- Groom landscapes by edging beds and walkways.
- Divide and replant perennials.
- Learn what plants need winter protection; many benefit from the cold.
- Only protect cold sensitive plants from frosts and freezes.
- Thick fabric covers secured to the ground are the best cold protection.
- Install micro-sprinklers to conserve water and water only where needed.
- Groom hanging baskets and planters by removing old flowers and lanky stems.
- Protect orchids and tropical foliage plants from temperatures below 45 degrees.
- Test soil acidity in azalea, philodendron and ixora plantings and adjust if needed.
- Dig and move trees and shrubs from one area of the landscape to another.
Vegetable and Fruit Gardening:
- Unless protected warm season plantings have been damaged by cold; remove as needed.
- Only one month is left for cool season plantings; add seeds or transplants to the garden.
- Make plantings of potatoes from seed pieces available at garden centers.
- Feed winter vegetables and herbs every 3 to 4 weeks or use a slow release fertilizer.
- Lingering warm season crops are not going to be good producers: remove, replant in spring.
- Start seeds of tomatoes, peppers, and eggplants in early January for March transplants.
- Prepare spring planting sites by adding lots of organic matter to sandy soils.
- Encourage pollinators to visit by planting clusters of flowers among vegetables.
- Save shipping charges; locate seeds, bulbs and transplants locally.
- Store saved seeds in the refrigerator in a sealed container until planting time.
- Add bird netting to strawberry plantings.
- Caterpillars are common cool season pests; control by handpicking or natural sprays.
- Repair grape arbors and trellises.
- Harvest herbs and start new plants to have a continual supply.
- Prune apple, grape, peach, pear and fig plantings.
- Plant hardy fruit trees, shrubs and vines.
- An acid soil is needed for blueberry production; have your soil tested before planting.
- Cloth covers, loose hay, and boxes may be needed for winter protection of some crops.
Indoor & Foliage Plant Care:
- Make a New Year resolution to add air purifiers to the home with fresh foliage plants.
- Keep existing plants a lot longer by giving them at least weekly care.
- Check foliage plants brought indoors from the landscape for pests.
- Use a mild soapy solution to wash indoor foliage to remove dust and control pests.
- Trim off yellow leaves and declining flower stalks.
- Move declining plants into the higher light levels.
- Water foliage plants when the soil dries to the touch.
- Move holiday gift plants to the patio to enjoy during warm days.
Vegetables: Asparagus, beets, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, celery, collards, endive, horseradish, kale, kohlrabi, lettuce, mustard, onion sets, peas, potatoes, radicchio, radishes, roquette, rutabagas, spinach, Swiss chard and turnips.
Herbs: Anise, bay laurel, cardamom, chives, coriander, fennel, garlic, ginger, lavender, mint, oregano, parsley, rosemary, sage, sweet marjoram, thyme and watercress.
Flowers: Alyssum, baby's breath, calendula, California poppy, cleome, candytuft, carnation, delphinium, dianthus, dusty miller, foxglove, gaillardia, geranium, hollyhock, Iceland poppy, lobelia, nasturtium, ornamental cabbage & kale, pansy, petunia, Shasta daisy, statice, stock and sweet pea.
Bulbs: African iris, Asiatic lilies, amaryllis, blood lilies, bulbine, crinum, day lilies, Louisiana iris, society garlic, spider lilies, rain lilies, refrigerated Dutch iris, tulips, daffodils and hyacinths for forcing.