With the recent record-breaking freezing weather we have experienced, it can be tempting to jump into pruning and replacing plants. As tempting as that may be, you could be removing living plants or causing additional issues by pruning too soon. For all landscape plants and trees, it is important to wait to prune until after our last frost date. This is the date that we would not expect any more frost temperatures based on historic averages. In Sumter County, March 11th is listed as the last frost date in the Old Farmers Almanac. Keep an eye on the weather, as you may notice steady temperatures before that.
Why wait to prune? Pruning can activate new growth, which is more susceptible to damage it another cold snap comes out way. The production of new growth after a frost or freeze relied on stored nutrients in the roots. If this new growth is damaged, there may or may not be enough stored energy for a second flush of new growth. This means pruning too early could mean the death of your plant that would have otherwise come back. Patience is important during this time.
Thinking about palms specifically, leaves can turn complexly brown after a cold snap, while the plant is still alive. Let us look at a few of the common landscape palms in Sumter County. A full list of palms for central Florida can be found here.
Pygmy Date Palm (Pheonix roebelenii) – These plants are cold hardy to 30oF, but readily survive 25oF. At this time, there are many in the area that look complexly brown, but do not fret, most of them should show new green growth in the coming weeks.
Queen Palm (Syagrus romanzoffiana) – This is another palm that you may see some leaf decline form the cold but being hardy to 25oF, these palms are expected to recover.
Sabal Palm/Cabbage Palm (Sabal palmetto) – You may have noticed that these native palms faired better than many in the landscapes. They are cold hardy to about 15oF. You should have seen little, if any, damage to these.
Date Palm (Pheonix dactylifera), and Wild Date Plam (Pheonix sylvestris), – both have cold hardiness to about 15oF, this is another palm you should see little to no damage from the last cold snap.
Senegal Date Plam (Pheonix reclinata) – Prefers temperatures to not drop below about 25oF. These palms may also look quite brown at this time. Wait a few weeks and watch for new growth.
Canary Island Date Palm (Pheonix canariensis) – These tough palms can survive near 0oF, though you may see some leaf damage from the recent temperatures.
European Fan Palm (Chamaerops humilis) – Cold hardy to about 20oF, you should see minimal, is any damage to these plants.
Mexican Fan Palm (Washingtonia robusta) – Another palm hardy to temperatures reaching about 20oF, these should also show no to limited damage from the recent weather.
Foxtail Palm (Wodyetis bifurcate) – These palms do not do well with temperatures below 30oF which falls into
USDA hardiness zones 10 and 11. You need to watch these closely to see if they come back. Wait several weeks to see if green growth emerges from the middle. If you do lose these palms, you may want to consider replacing them with a plant that is more cold hardy to this area.
Christmas Palm (Adonidia merrillii) – These are another palm that you may see significant damage on. Hardy to about 30oF they do best in USDA hardiness zone 10B, which is farther south than Sumter County. This is another case of considering a palm better suited for our USDA hardiness zones of 9a and 9b in Sumter County.
Bismarck Palm (Bismarckia nobilis) – Another palm best suited for USDA hardiness zone 10A, these may show signs of light damage now that may worsen over the next few weeks.
Why would some plants come back, but not others? In landscapes, just as in natural areas, we are microclimates. These are areas of the landscape that can experience different temperatures, wind, rain, and other environmental factors. If your plant was in a more protected area of the landscape, you have a higher chance of recovery. Remember that palm recovery takes time. Once a leaf turns brown, it will not become green again. You must wait for the crown to grow out. Remember, never prune leaves that still have green on them. Wait until they are fully brown before removing.
How do you manage the damaged plants in your landscape in the meantime? Water at the base. Avoid getting the leaves wet. As the temperatures warm and it gets closer to time to prune, you can lightly fertilize, but not before then. Remember, you do not want to encourage new growth while we could still experience additional frost/freeze temperatures. Your plants may look worse before they look better. It is all part of the regrowth process.
If you have specific questions about your plants, send photos and questions to your local extension office.
4
