THE AGRONOMIST ANSWERS ON HOW TO GROW AND CARE FOR PLANTS
HOW DO I ADJUST WITH THE FERTILIZATION OF MY FRANGIPANES (PLUMERIA)?
QUESTION BY MAURO
Good morning doctor, I turn to you for advice: I have about ten frangipani plants (brought from the sierra leone and nigeria, where I worked), one of which in the ground and the others in pots and all with good flowering; I used to fertilize them "ace of clubs" and "synergon" on an alternating weekly basis both as irrigation and foliar irrigation, and as a product. The plant in the ground (years) is small in size (about 2m high with a foliage diameter of about 2m) with many branches and leaves about 20/25 cm long, while those in pots have developed more than 2m in height. with very long single branches (so much so that I have shortened them and I make cuttings!) and leaves of 35 / 45cm. I presume that I exaggerated with the fertilization and I thought of using a fertilizer that an American site indicates as ideal for plumerie (super bloom or carl pool's BR-61) which have a composition of 12/55/6. Here (sardinia prov. Ca) I contacted several fertilizer and plant resale shops, and, who told me that fertilizers with these% do not exist, who that fertilization must be monitored and is only possible in the greenhouse, and various other nefarious news ; what kind of news do you give me?
I think that as soon as this long cold wave ends, the vegetative activity begins, in some branches there is already a hint of a bud.
Dear Mauro, congratulations for the choice of plumeria, a very beautiful plant and unfortunately not very widespread.
Reading your question I do not understand one thing: so far for your plumeria you have used the Ace of flowers which is a fertilizer 20:20:20 associated with the Sinergon which is organic Nitrogen with some microelements and you have found it well (apart from the overuse) why would you want to change? Not satisfied with the blooms you have had?
Certainly a fertilizer with a high Phosphorus content is good for plumeria but even if you do not find that precise percentage in my opinion you can safely use a fertilizer that has a higher concentration of Phosphorus and much less of Nitrogen. You could continue to use the Sinergon which being organic Nitrogen is very welcome to this plant but replace the Ace of clubs with another one that has a higher Phosphorus title and very low Nitrogen (taking into account that you already administer it with the other. fertilizer) even if not in those percentages and it would be fine. Go to an Agricultural Consortium and also throw an eye on fertilizers for orchids where it is easy to find "anomalous" percentages compared to fertilizers for other plants. Or if you really want to try that solution you can buy fertilizers containing the individual elements that you can easily find on the market and make the proportions yourself in order to get to those percentages even if I would advise you not to push too hard with fertilizations and to halve the doses that you have so far used if you want to continue fertilizing on a weekly basis or to continue using those doses but every two weeks.
Remember in any case that starting from autumn and for the whole winter, to completely suspend the fertilizations because the plumeria goes into total vegetative rest so you must not give fertilizers that would accumulate in the ground creating a harmful environment for the roots. of the plant.
If you have any doubts write me again.
Dr. Maria Giovanna Davoli