How to Protect Plants from Frost in Florida - Our Northeast Florida Garden After the Freeze

We feared the worst with the promise of down to 24 degrees F by Christmas here in St. Augustine, Florida. Thankfully it seems as if we only made it down to 28F in our location (zone 9a), which is something we've had before, but it is also the lowest temperature we have measured by our home in the last 5+ years that we've lived here.

While many of our plants look sad, we're confident most will survive. Yesterday, we uncovered some plants, since it was not going to go below freezing, and today we uncovered the rest and opened up our diy greenhouse which is our attempt to create a semi-permanent solution for plant protection from frost in our growing zone, where we only get freezing temperatures a few times a year. 

Make sure to take a look at the tour of our 500 sq ft side garden before the frost at the How to Grow Food in Small Spaces post. This area was a wasted space, because it is so close to the neighbor, but now it is a lush food forest with a great diversity that attracts lots of pollinators and wildlife. In the below video, you can see how this food forest area did in zone 9a after a 28F freeze. 

How to Protect Plants from Frost in Florida

If you're wondering how to protect plants from frost in Florida, take a look at our video tour to show you what we did, and read on to get more details. 

Florida is such a diverse state with multiple growing zones, and even within each growing zone there are microclimates. If you live close to the beach or close to water, you may not get as low temperatures as other places in your growing zone, but if your garden is exposed to wind, then you will likely suffer greater damage than a similar fenced-in garden with lots of tree canopies etc.

How to Protect Plants from Frost:

• Mulch heavily with woodchips and leaves. Just make sure to clean the mulch off the trunks of the plants after the danger for a freeze has passed.
• Water deeply before the freeze, but try to keep the water off the leaves, and water while early in the day, so any water on the leaves can evaporate.
• Cover with sheets and blankets, and clip them down with clothespins.
• If at all possible, cover to the ground and use rocks and other planters to hold down sheets.
• Do not cover with plastic, as the plants may get burns once the sun gets up.
• If you do cover with plastic, make sure to remove the plastic in the morning to prevent burns. 
• Create a mini greenhouse for plant frost protection. Just make sure that it is taller than your plants, so plants will not get burned during the daytime.
• Move plants into your garage.
• Use bulb Christmas lights around your bananas and sensitive trees.
• Select varieties that hold up well against low temperatures.
• Know what plants can handle a mild freeze vs. a hard freeze.
• Young fruit trees are more susceptible to frost damage than more established trees. 
• A larger trunk means a tree is better protected. We prune our fruit trees small, to make them easier to manage, to protect and to have room to grow a myriad of different varieties in a small space.
• Plant between structures
• Create microclimates
• Plant cold-sensitive plants in pots, so you can move plants to safety in case of a freeze.
• Plant cold-sensitive plants close to your home.
• Take cuttings of plants and trees and start indoors for spring planting
• Water before and after a freeze.
• Add bottles with water (not completely full) inside your frost protection 
• A tree canopy can help protect the plants below it against frost and hard winds.

We are lazy gardeners, and we do not like putting our plants to bed, but if you want to grow tropical fruits in the northern end of Florida, and if you want to push the growing zone and the growing season, then some frost protection for your plants will be necessary. 

We are trying to come up with solutions that will make this easier, because as frugal gardeners we grow a lot of fruit trees from seeds and cuttings, and these need to be protected until they reach a certain size.

Tropical fruit tree frost protection in Northeast Florida 

This year we have created a semi-temporary greenhouse for plant frost protection, so that we can easily cover at night and uncover in the morning to prevent any burns. 

We also take cuttings from plants in the ground, and if we can we will put a bucket or sheets over some of our favorites.

Our 9a Garden After the Freeze: 

Our recent double-blooming  Dwarf Musa Cavendish banana tree was on our biggest worry list, but it seems to have managed well. 

It was the only banana that we covered, and we only covered it, because of the new banana hands. Because this banana is still growing bananas, we've got banana-peel water ready for it, and we will be adding more compost to feed it, now that the freeze has gone and warmer temperatures are returning. 

Double-blooming Musa Cavendish banana tree after a freeze in Florida 

All of our bananas have come back from a two-day night freeze before, so we think they will be fine. We've got Dwarf Musa Cavendish Bananas, Dwarf Red Musa Cavendish banana, Raja Puri Bananas, Ice Cream Bananas, Dwarf Namwah Bananas and Grand Nain Bananas plus several bananas of unknown variety, and while they look sad after freezes, they usually recover quickly. We do not cut our bananas to the ground, but ones we're on the other side of Valentine's Day, we'll cut of any dead branches.

We plant most of our bananas close to our home to serve as protection, but we also have bananas at the land, where there are no structures, and they all come back without being covered.

This year we're growing lots of dragonfruit varieties. For the past few years, we've been experimenting with growing dragonfruit from seeds inside and outside, and they are very slow growing. 

The happiest one of our dragonfruit cacti from seed is one that is in a small container on top of a rain barrel. The southeast corner outside of our house is a suntrap, and this little dragonfruit sure seems to like it, and it did not get affected by the freezing temps at all.

Seed-grown dragonfruit after a freeze.

Dragonfruit grown from cuttings are faster-growing and thereby produce faster, and we've got five new varieties this year. 

Dragonfruit surving a freeze in Northeast 

Each variety has a pole inside our new greenhouse area, but we also left some dragonfruit from three varieties outside to see how these did, and neither of these suffered any damage.

We moved a few pomegranates of various sizes underneath our halfroof just in case the temperatures did dip below 28 degrees F, but at 28 degrees F/-2 degrees C, no damage was sustained to any of the pomegranates we left unprotected.

Every year we experiment with our seed-grown starfruit trees. 

Unprotected Starfruit (Carambola) grown from seed after a freeze in Northeast Florida

Last year we protected one starfruit (Carambola) and left one out, and the one left unprotected did just fine.

The papayas look just as sad as the bananas, but they do not look as if they sustained fatal damage, so we think they will recover. We take a watch and see approach, but you can read about how to save your papayas after a freeze here.

We had one very exposed papaya (a volunteer) that did amazing and barely flinched at the freeze. You can see the bougainvillea in the back got hit by the cold, but this too will come back.

A volunteer papaya after the freeze in St. Augustine, Florida.

We have many seed-grown purple passionfruit vines around our home. One 2-year-old passionfruit vine just produced passionfruits for the first time this fall. It is a bit late in the season, but it suffered severe frost damage earlier in the year, so we cut it back, and it had quite a comeback.

Purple passionfruit from seed after a freeze in Florida 

This passionfruit vine with fruit on was mostly protected inside our diy greenhouse, and any passionfruit vine not protected suffered freeze damage. From past experiences, we know that they will come back. 

Purple passionfruit after a freeze. 

We will cut back the frost-damaged passionfruit vines, when all chances of frost have passed, and they will come back even stronger growing as much as 6 yards, if grown in full sun. 

Sweet potato vine frost damage

Just like the passionfruit vines, the sweet potato vines suffered greatly in the freeze. We had cut a bunch and fed to the chicken before the freeze, and while some will die back completely, some will recover like previous years. We enjoy eating sweet potato leaves all year round, which is why we brought some sweet potato cuttings inside, so we can continue to harvest sweet potato leaves throughout the winter months. 

Cuban oregano is cold-sensitive, but will regrow in the spring.

Cuban oregano is another cold-sensitive plant in our garden. It even suffered damage inside our frost protection area, but most of the Cuban Oregano will come back in the spring.

Avocado seedlings, pomegranate seedlings and peppers after the freeze.

We have loads of avocado trees in various sizes and growth stages, and while we did put a couple of young avocado seedlings inside the greenhouse area in case the temperatures went below 28F, we did confirm that it is not needed at those temperatures. None of our avocado seedlings suffered any frost damage, and we prefer to leave them outside, so that they can harden off and become more resilient avocado trees. 

Tropical spinaches such as Sissoo Spinach, Hoan Ngoc, Longevity Spinach, Okinawa Spinach, Malabar Spinach and more grow in many places throughout our garden. Most were left to fend for themselves, but we took cuttings, and made sure to have at least one rooted cutting of each in our frost plant-protection area, and we hope some will come back in the spring.

A bucket and a cut milk carton protecting Longevity Spinach from Frost in Florida. 

A bucket and a cut milk carton protected some of our Longevity Spinach from the freeze, but one leaf had been left outside the carton, and the frost damage to this leaf is clear.

Longevity Spinach after having been protected from frost in Florida.

How to Save Your Plants After a Freeze:

• Water well before and after a freeze. 
• Make sure to uncover any plastic coverings during the daytime to prevent burns on your plants.
• Leave pruning until the spring in most cases. We usually wait with pruning until after Valentine's Day.
• In the case of plants such as papayas, it might be better to cut the papaya early, if part of of the papaya trunk is damaged beyond repair in an early freeze. This way, you can protect the cut part in case of another freeze. 
• We make another exception to the no-prune philosophy, when it comes to plants with rhizomes such as cannas, ginger, turmeric and shell ginger. 
• Make sure to clean extra mulch off the trunks of the plants and trees after the danger of frost has passed.

Whenever we have more than one of a plant, we always try to experiment to see, which plants do well in a freeze, and which ones need to be covered in zone 9a/9b before a freeze.

Some plants such as Cuban oregano, Insulina, Passionfruit, Moringa and Katuk may die back but will likely regrow in the spring. If you want to start the season of strong, you can protect these.

Insulin (Insulina) plant with frost damage - no protection. It will come back in the spring. 

What to Cover Before a Mild Freeze in zone 9A/9B:

• Young tropical fruit trees such as Black Sapote, White Sapote, Blackberry Jam Tree, Guavas, Cherry of the Rio Grande, Barbados Cherry, Suriname Cherry, Jamaican Cherry, and Jaboticaba.
• Tropical spinaches such as Sissoo, Okinawa Spinach and Longevity Spinach.
• Cuban oregano
• Passionfruit vines with fruit on them
• Papayas if small and you can cover, but they will survive mild night freezes for a day or two.
• Sweet potato (or simply take cuttings or leave sweet potatoes in ground and many will come back in the spring)
• Peppers (Some pepper plant will survive a mild freeze, and some will not)
• Hoan Ngoc - we left some out and protected some. The unprotected Hoan Ngoc looks sad, but it survived.
• Tomatoes
• Insulina (It will regrow in spring, but if you want to get a headstart on the season, protect it from frost.

What not to Cover Before a Mild Freeze in Growing Zone 9A/9B:

1. Avocado seedlings
2. Dragonfruit
3. Starfruit/Carambola
4. Bananas of certain kinds - grand nain, musa cavendish, raja puri, dwarf namwah and ice cream bananas have survived freezes with temps down to 28F in our gardens. 
5. Olive trees
6. Native trees such as Elderberry, beautyberry, American Persimmons and Paw Paw.
7. Loquat/Japanese Plum
8. Grapevines
9. Mulberry
10. Blackberries (These love the cold)
11. Raspberries (These love the cold)
12. Blueberries (These love the cold)
13. Apple trees (These love the cold)
14. Plum trees (These love the cold)
15. Peach trees (These love the cold)
16. Lemongrass
17. Figs
18. Shell Ginger (While they may suffer some damage)
19. Passionfruit vines without fruit (They may suffer damage, but will recover)
20. Citrus
21. Date palms
22. Chaya (Chaya die back in a freeze, but will likely regrow in the spring)
23. Moringa (Moringa will die back in a freeze, but will likely regrow in the spring)
24. Older Guavas and other fruit trees with a substantial trunk size. 
25. Prayer plants (Will die back but come back in the spring)
26. Gardenia 
27. Insulina (Will die back but regrow in spring)
28. Peace Lily (Will get damage but regrow in spring)
29. Cranberry Hibiscus (Will die back but regrow in spring - save seeds if possible)

Our Tangerine tree did great, as did all of our other citrus trees after the 28F freeze in Northeast Florida.

Now, if temperatures below 28F/-2C are forecasted, we recommend protecting bananas, papayas and passionfruit vines if possible, but as always we believe in planting so much that it is not a disaster, if a plant is hit by frost or insects. We do not use pesticides, and in return we've got a garden full of beneficial insects and pollinators.

Of course, you can just stay away from any frost-sensitive plants, and you won't have to worry about how to protect your plants from a freeze in Florida. Or you can treat all of your plants like annuals, and start new plants in the spring.  

However, with a little planning the growing season in Florida can be extended, and if you nurse smaller fruit trees to maturity, you can soon have a diverse food forest or fruit trees that can sustain themselves when the temperatures do dip a few times a year.

You have seen the damage that freezing temperatures can have on a food forest in zone 9, but take a look at just how much food we're growing in this 500 sq ft space at the side of our house in our Growing Food in Small Spaces post. 

Help support us by connecting with Dancing Treetops on Facebook, Instagram, You Tube and Pinterest. We want to see your garden pictures.