Deciduous Trees –
March is the month things can really start moving in Northeast Florida, and your deciduous trees will tell you so themselves. Watch for buds beginning to swell and open — that's your signal that the tree's energy has shifted out of the roots and back into the core of the tree. This is your repotting window, and in our climate it can be a narrow one, so stay attentive. If you haven't repotted yet and buds are pushing, don't panic — you can still repot right up until the leaves begin to fully emerge, but once the foliage opens out, it's best to wait until next year.
In North Florida it’s quite popular to collect wild bald cypress — if you did so the last month or so, resist the urge to do anything else to it! Bald Cypress are somewhat prolific healers, but if it was nice enough to collect then it should be nice enough to wait another year to do any major styling. I would hate to lose a beautiful collected baldy because I made a hasty decision. Now, if you collected your cypress in previous years — repotting is viable assuming buds have not opened up yet, but keep in mind we are mere days away from it being too late for that. Additionally, if you haven’t collected any baldies yet, you should wait until next year for to do so. Another thing to be aware of is that bald cypress notoriously suffer from root aphids and root mealybugs, so take a good look at the roots while you have the tree out of the pot.
Weather Connection: Jacksonville's March days can reach the mid-80s, but there’s always the potential for a surprise late frost in March, so continue to monitor the weather forecast. March is also usually very dry and windy, so make sure trees that have just been repotted are protected from drying out. Watering needs will increase significantly this month compared to February — trees coming out of dormancy are drinking again, and freshly repotted trees especially need attention. Combined with the lack of rain we’ve been experiencing, be sure to give those awakening trees ample hydration.
Conifers and Broadleaf Evergreen Trees –
March is a great time for conifer repotting in our zone — act early in the month if you can so you don’t look up and it’s already Easter! Remember, you do NOT want to bare root your conifers. They need to maintain some amount of original soil so you don’t strip them of the mycorrhizae they need to remain healthy. It’s helpful to keep in mind that by the time we get deeper into spring, we are reaching the end of the repotting window for conifers and broadleaf evergreens.
For junipers specifically, a critical heads-up: be careful when wiring junipers as bark can very easily slip from the cambium this time of year. If you need to do any bending or repositioning, do it early in March before growth accelerates, and handle bark with extra care. Foliage pads should be thinned and fanned out to let light and air in — dense pads increase the risk of pest infestation, and with our humidity ramping up, this is not a step to skip. Their are a few common diseases that can infect our junipers, so this is a good time to apply a preventive fungicide spray if you haven't yet.
If you repotted your broadleaf evergreens (azaleas, boxwood, olive, etc.) last month — give them a sheltered spot and keep an eye on soil moisture as temperatures warm. Wounds heal faster when the tree is actively growing because the plant is manufacturing more food and producing cambium at a faster rate, so trees that had root work done in February and March are actually well positioned to recover as spring arrives. If you haven’t repotted yet, it is not too late, but the hotter it gets the more stress these trees will experience so the sooner the better. Again, prioritize your trees’ needs, if repotting is more important than major stylings then do what is best for the health of the tree and save that styling for the appropriate time. If it can go another year in the same pot and you’ve got issues you need to correct now, then by all means correct away!
Planning Ahead: Now is the time to begin fertilizing. Use a fertilizer that contains all the major elements — nitrogen, phosphorus, and potassium — as well as minor elements. Apply a slow-release fertilizer about a week before you expect new growth; if using a liquid or quick-acting fertilizer, start when you see the new buds begin to open of that aligns with your goals. It’s important to think about what applying that fertilizer will do to that tree given its current situation. Sometimes applying fertilizer before the first push will increase leaf size and it may be better to wait until after the first leaves have pushed if you’re working on reduction.
Tropical Trees –
March is a transitional month for your tropicals — still not quite time to let your guard down completely regarding temperature, but things are improving rapidly. Tropical trees should be out of the greenhouse as temperatures are steadily hitting 50+ overnight, but it's still not warm enough to repot them. Hold off on any repotting, heavy pruning, or defoliation until nighttime lows are consistently in the mid-60s, which is more reliably an April situation here in Jacksonville.
This month is also a great time to get your fertilizer regimen organized. Tropical trees experience year-round growth and should be fed on a monthly basis during the fall-to-spring transition period, increasing to a more frequent schedule as the growing season fully kicks in. If you're running a systemic fertilizer, review your notes (assuming you have them) on when your last application was. It's very easy for feeding times to slip by unnoticed.
Pest awareness also begins this month in earnest. Scale and other insects are a common issue on tropical species — signs include weaker growth on certain branches, small bumps or shells on the bark, and black sooty mold on leaves. Catching it early is far easier than dealing with a full infestation once the growing season is in full swing.
Miscellaneous –
Even though March 20th is officially the first day of spring, our plants in this zone began reacting to spring conditions last month (I’ve got azaleas that went into full bloom before that last dip into the 30’s)— which means March is less about waking up and more about keeping pace with trees that are already moving. The key risk this month is being caught flat-footed. Trees don't wait, and a week's hesitation on repotting a deciduous tree whose buds have already pushed can mean another year in the wrong pot.
While it’s possible some trees can survive being repotted at any time, it is better to complete repotting at the right time so trees can achieve growth in optimal conditions and not experience setbacks. Remember what’s ahead, Florida summers are unforgiving, and a tree still recovering from root work in June is a tree fighting an uphill battle. Do the work while conditions are in your favor!