lack of light could infringe on vigor ..

but many plants only flush once per season.. and not in winter.. are you down under?

3 feet form the window does seem a bit far.. especially if its not a south facing window the sun shines into ..

otherwise.. the plant had been divided.. and transplanted.. and you just think its not growing fast enough.. it was obviously severely stressed.. sometime is takes longer than we wish to get moving again .. i usually figure it is growing the roots it need to grow the leaves you want.. but you cant see the roots.. so you are left wondering.. so tip one out of the pot.. and LOOK.. and then slide it back int he pot.. tell us what you saw..

whats in the window.. and why cant you move some of those 3 feet out.. and move these in the window... rotate your plants once a month.. and you will probably find they all end up happy ... and if its not plants.. then esplain, lucy

ken

im thinking his hands hurt after this.. lol ..

https://www.youtube.com/watch?v=ZUIRuS1OI50&ab_channel=Jetjock190

Agree with Ken. "Whale's Fin" is Sans masoniana. They are big and SLOW growing. I think your Sans will do better with more light (not direct sunlight through a south window -- but "bright" light near a window). But to expect one leaf that grew roots to be shooting up a new leaf in 4 months is unrealistic, especially for a Sans. They are slow growers.

I have smaller Sans that I have split and divided. It took one of them 8 months for a new pup to emerge. Now, another 5 months after that, I am seeing just the tip of a whole new leaf coming up through the soil. If it were me, I would give it brighter light and patience.

Ken I'm in Missouri and yes, there are plants in the window. Window space is premium around here due to there being large trees shading the house so many of my windows don't get enough light for plants.

Mine took nearly a year to produce any new growth and when it did, it wasn't a new leaf on the original leaf but a whole new pup. Treat it right and give it time.

Plants make their own food (simple sugar/ glucose) during photosynthesis. The sequence that occurs in order to form a stem from a leaf cutting includes dedifferentiation of leaf tissues and the redifferentiation of those tissues into both root and shoot meristamatic (think STEM cells) regions. Redifferentiation into stem tissue is primarily driven by the presence of several growth regulators (hormones), and the availability of a food source, which would necessarily come from the plant's stored energy reserves or from current production of photosynthate (sugar). If by chance your plant was low on energy reserves, and it would normally be at its lowest ebb in early April, and the light source is such that all current energy from photosynthesis is barely enough to keep the propagule's living tissues alive and its systems orderly, it could take a very long time before you see a shoot. You're watching for a new leave but are actually waiting on the process of dedifferention and redifferentiation and its accompanying formation of an apical meristem, which is where extension growth (growing longer) takes place.

Additionally, the plant contains internal chemical messengers which keep plant central apprised of whether or not the root system is well enough established to support new top growth. Root growth always precedes top growth, which prevents the plant from growing top/stem growth the roots are unable to keep supplied with water/nutrients. Your plant is being suppressed by a lack of roots or a lack of food (fertilizer is not plant food).

BTW, an inadequate light source can't "infringe on vigor", as vigor is an inherited trait with which Mother Nature has endowed the plant. However, an inadequate light source can/does limit the plant's vitality. Vigor is a constant, an innate quality having more to do with a plant's ability to resist stress and strain, while in contrast, vitality is variable - a dynamic condition that indicates the measure to which a plant is able to cope with the hand it's dealt, culturally speaking. A good way to look at the difference between vigor and vitality is to look to genetics for the level of vigor and to things cultural for the plant's vitality.

Al

I agree with all above, these are very, very slow to produce a new leaf sans. I have both the regular and variegated form and they are both slooow. That is not always a bad thing, as long as they are healthy, as you can put your beautiful leaf in a nice pot and not have to worry about potting for awhile :)

Thank you Al, that's very interesting. Are you horticulturist or a botanist?

..... just a guy who took a keen interest in soil science and how plants work, in order to rescue myself from my own ignorance as it pertains to the art of bonsai. Anything I've learned is an outgrowth of my efforts to grow healthier and more evocative trees.

Al

To give you an idea what is going on below the surface.

Just noticed yesterday that my Mansoniana is making a pup. This is the first new growth since last year. The original two leaves are the ones at 11:00 with the stick and the velcro which I purchased bare root at a rare plant charity event in May 2019. In three years, it's only grown one leaf, then another set of two, and now this pup.

This was the reason I gifted out my mansoniana. Slow and then only a few leaves. Under the soil a lot is going on. They grow roots like sweet potatoes. Very massive root system. Called pot breakers.