Since it is 15 years old, I would leave it alone until the end of March, so that we are past the point where we could get another freeze. Birds of paradise don't bounce back quickly after a freeze. it is best to let spring get here, wait for new growth to emerge, give it some fertilizer and then prune any dead leaves. if you are zone 9a, this plant has survived because of several years of mild winters.

First of all, the snarky comment from Arunski about shoulda coulda was unnecessary --who says something like that? I love plants and I'm pretty good at growing them, but sometimes we plant lovers see a plant and buy it, not really knowing that much about it. I bought a white bird of paradise summer 2019 from Home Depot because I loved the look of it. It was about 2 feet tall. Planted on my covered porch in a beautiful pot and it grew unbelievably over the summer. I had to bring it inside for the winter and it has continued to grow in a corner that has a window, but it is extremely filtered light from plants outside. I purchased a cheap LED floor lamp from Amazon that I can bend to whatever position and the plant seems to love it, even though 2 feet of it are above the lamp. Watering has been limited due to spillage issues, and still it grows. It's about 6 feet tall now with new growth all the time. I had no idea it would get this big, but I have 4 more feet to go before I have to move it so we will see what happens. I could move it back on the porch, but it has grown too big to move I think and everyone who walks in the door has a fit over it. I think I will buy a nice self watering planter and see if that helps. I've only fertilized it twice. Who knows? Maybe it knows it's loved and likes the home it lives in. We have a good vibe.

" but since we are in a drought here, we only water for 2 or 3 minutes every few days." This type of watering routine will keep barely anything other than the most drought tolerant species alive! With an automatic sprinkler system, you are losing a good portion of the water emitted to evaporation, as much as 50%......and it really doesn't matter what time of day the system turns on. And with a big, leafy plant like the Strelitzia, you can bet 90% of the of water NOT lost to evaporation is not hitting the root system - water just on the leaves is not a viable substitute for that. In short, your watering routine is likely not delivering anything of value to the plant in terms of needed moisture. Reprogram your sprinkler system so that the water comes on less frequently but for a longer duration. Can't tell you exactly how long - you will have to do some testing to determine a correct interval, but you want any irrigation water to penetrate as deeply into the soil profile as possible, at least 6-8", more if possible. Or use the hose on a slow trickle left in place at the base of the plant. Again, the length of time will be determined by how well and how fast the water percolates through the soil. And once a week should be more than adequate for any plant well established in the landscape, perhaps less often for very drought tolerant species.. For a state that is suffering from an extended drought situation, I am amazed at how inefficient and wasteful most CA watering practices are! I am not an irrigation contractor but I am a landscape designer and certified horticulturist and DO know how plants should be watered and I could make a fortune redesigning CA irrigation systems to deliver water more efficiently and with less waste. Pop-up sprinkler systems are fine for lawns (provided they are programmed correctly.......and few are) but they are a waste of time, money and a valuable and precious natural resource when used for regular landscape plantings. Investigate converting your system to a drip or low emission system for all the landscape plantings. And remember that low and slow or less frequent but longer watering periods will provide much better results.

Any plant in a pot needs repotting on a regular basis. There will be some who make the claim that a ponytail palm will "thrive" on neglect, but that is not true. That the plant will suffer a lot of abuse without succumbing to the stress cannot be taken as indication it approves of the stress. No plant does, and neglect is always accompanied by stress ...... or it isn't neglect. The most often overlooked key to a persistently healthy plant is regular repotting into a soil that won't hold enough water to be a limiting factor. At the point your plant can be lifted from the pot with the root/soil mass intact, it will benefit from a repot ...... and a repot is much different than potting up. Potting up ensures the limitations imposed by root congestion remain, where repotting eliminates entirely the limitations associated with root congestion. Over-watering in poor soils can be lethal. The idea is to use or make a soil that allows you to water to beyond the point of saturation, so you're flushing the soil of accumulating dissolved solids (salts) when you water, this, without the plant having to pay an "over-watering tax" in the form of significant loss of potential. Tight roots can rob your plant of more than 90% of it's potential as the congestion reaches the critical stage. All the succulents, trees, and most houseplants I grow are grown in this medium: Best luck! Al