Jordan (z7) Oh! I've read that rubber plants like fertilizing, that' why, but in this case I probably shouldn't!

The last fertilizing was about two weeks ago, so I assume it's still doing OK?

When should I start to fertilize it?

Yes, the leaf is very shiny-green, and I check the soil regularly.

Jordan (z7) Yes it's propagated from a stem, and it has 3 big old leaves from the original stem.

Jordan (z7) Thank you very much, Jordan! This is very helpful.

I wonder if the new leaves will ever grow to become as big as their mother's, or it will remain small as it's a propagated tree and planted in a pot? The cutting is an exact clone of the parent plant, so its genetic potential is equal to that of the parent. Too, Ficus is programmed such that each leaf occurring along the length of a branch will be larger than the immediately previous leaf, within the limitations imposed by cultural conditions. Is there anything I can do to help them grow bigger? knowing that I've fertilized it twice since it started to produce leaves. Often, cuttings are limited by a lack of root mass. Chemical messengers within the plant are constantly informing plant central whether or not there is enough root mass to support more top mass. If there is not, top growth will be suspended until new roots have grown, sufficient to support more top mass, or regeneration of damaged or dead roots has occurred. That you've fertilized after 3 months is not an issue in itself. In fact, it sounds like, if anything, it might be on the light side (not often enough), but that depends on what you're using and your watering habits. Ask if you want to explore how to put together a nutritional supplementation program that is easy and gives you complete control over what nutrients your plant receives and when it receives them.

So, anything you can do to promote root health and ensure cultural conditions (moisture/air levels in the soil, light levels, temperature, nutrient load, humidity .....) are all in the plant's 'sweet spot' will encourage growth.

Do not fertilize new transplants. It can actually damage the plant. While you might be able to find some anecdotal information to support that contention, and there is some information supporting the idea that low fertility in the first week after TRANSPLANTING a plant can hasten root colonization of the soil mass, you'll find nothing scientific to support the idea that cuttings that have recently struck or plants recently transplanted will be damaged or otherwise suffer from a normal nutrient load.

You shouldn’t have to fertilize it. Unfertilized grow media are a poor source of nutrition, so for best results, all but a very few plants need supplemental nutrition (fertilizer) in the medium at all times. Transfer it to the next larger size up container in a month when the roots are a bit more esablished and about to outgriw the current container. Potting up (as opposed to repotting) is a half-measure which ensures the stress associated with tight roots remains a limitation until a pair of human hands gets into the middle of the root mass to alleviate problem roots and congestion. For best results, potting should take place well before the root/soil mass can be lifted from the pot intact. If the root/soil mass is left to grow until it CAN be lifted from the pot intact, only repotting will reliave the stress entirely.

Did you propogate a stem or a leaf? While a Ficus leaf cutting will often grow roots, the cutting must include a node if a stem is to develop. Ficus tissues are unable to dedifferentiate then redifferentiate to form a stem unless a node is part of the cutting. If it is a stem, go ahead and remove that large bottom leaf to free up the plants resources to encourage new growth. Each leaf is a food factory that captures the sun's energy and turns it into food (sugar/ glucose). There is NO upside to removing a healthy leaf from a developing rooted cutting, only a downside. Removing the leaf with a branch growing in the axil simply reduces available energy. It does not "free up resources to encourage new growth". In fact, since the leaf contains mobile nutrients and other 'recyclable' resources, removing it from the plant is essentially discarding assets already paid for.

Al

You should remove any large lower leaves so that the cutting transfers the nurrients and growth to the apical stem and newer top leaves. Sorry, it doesn't work that way. The plant's food/ energy comes from photosynthesis, so the greater the collective photosynthesizing area of leaf surfaces, the more food/energy the plant makes and the faster it grows. You only remove the old/mature leaves when you want to SLOW growth, which produces smaller leaves and shorter internodes.

do not remove the newer top leaf, It’s needed for photosynthesis. The new top leaf is needed neither more nor less than any existing leaves on the tree. Leaves produce food. More food production = more growth. The bottom large old leaves should removed as they are draining the plants resources. No. Lower leaves are also contributors to the amount of food energy the is able to create. The plant doesn’t need all those leaves to sustain it’s new form as a smaller plant (cutting). It may not need all existing leaves to maintain viability, but if the plant owner wants an increase in growth rate and/or vitality levels, all healthy leaves leaves are essential to that end.

The nutrients of the soil medium are apparently sufficient. It is always a good idea to avoid additional fertilization until new growth has established. Sufficient for what? To ensure the plant remains viable or to ensure the plant has the best opportunity to realize as much of its genetic potential for growth and vitality? If you're suggesting the later, you're definitely wrong in that line of thinking. Nutrients are not plant food - they are the building blocks plants use to grow. The energy needed to assemble those building blocks comes from the product of photosynthesis - sugar/glucose.

When you remove a healthy leaf, it's always a setback in terms of energy. As a bonsai practitioner, I constantly use full or partial defoliation as an energy management tool, to reduce the rate of growth of certain branches or areas of the tree. Sometimes, slowing certain parts of a tree down so other areas can catch up is desirable from an aesthetic perspective, but as noted, the technique is always used with the understanding that any desirable effects come at the price of a reduction in both vitality and growth rate.

Al

When you START a cutting, it is usually advantageous to reduce the number of leaves on the cutting so the cutting can absorb enough water to satisfy the needs of the remaining leaves. This helps the cutting avoid total collapse due to the inability to keep the volume of leaves on the cutting HYDRATED. ANY time a leaf is not pulling its weight in terms of being a net user of energy as opposed to a net user of energy, the plant is informed of the predicament by its internal chemical messengers and begins the process of shedding the lazy leaf. While the grower might need to play a part in reducing the volume of foliage left on the cutting when it's stuck, once the cutting is rooted, all foliage remaining on the plant is an advantage because the leaves are the plants actual food factories.

Roots are the primary pathway by which nutrients are acquired, and leaves and their ability to synthesize food are the primary source of energy for the plant. The leaves you are suggesting should be cut off are providing the food/energy required to produce the next generation of leaves and the roots that support them with water and nutrients. Removing leaves from a cutting after it's rooted has only the potential to be limiting, so there is no 'upside' for the plant. What you suggest is like reducing a human's food intake for the weeks immediately prior to running a marathon.

Taken from what you linked us to:

"New roots must be formed as rapidly as possible if the new plant is to survive." The ideal situation would be to maximize the leaf area of the cutting w/o leaving so much leaf surface area the rootless cannot keep the remaining leaves hydrated. Once the cutting is harvested, excessive water loss must be prevented. To minimize water loss: ..... 2. For a stem cutting, remove some of the leaves. Most of the water will be lost through the leaves, so by decreasing the leaf surface you also decrease the amount of water loss. A general rule of thumb is to remove 1/2 to 2/3 of the leaves. Cut remaining leaves in half if they are large. This is entirely consistent with what I said.

Encouraging Root Formation

Read the following carefully: Cuttings use energy to form new roots. If the cutting has leaves, most of the energy comes from photosynthesis. Expose these cuttings to bright light, but not direct sunlight, during the rooting period. If you use hardwood cuttings that have no leaves, the energy will come from reserves stored in the woody stem. For best results, select shoots that are robust for the species. Since you want all the energy to go into the new roots, make sure you cut off any flowers or fruits that would compete for energy. Notice it says to remove "flowers or fruits". Nowhere does it suggest you remove leaves from already rooted cuttings. This is because flowers and fruits are always net users of energy, while leaves are net producers of energy.

Sorry, Ran. I didn't want you to be confused by the erroneous advice, or worse, have cuttings fail because you followed it.

the first new leaf stopped growing, while another new leaf is already coming out now. I meant to address this in my first post. The stalled growth of the new leaf is very likely due to poor root function or poor nutrition. When enough roots die, the plant's chemical messengers send signals to stop top growth until enough roots are regenerated to support more top growth. That's why when seeds sprout, the long root radicle (taproot) extends into the soil where it has access to water and nutrients before the first leaves open. Often, over-watering causes a cycle in which fine roots die, then the plant must regenerate the lost roots before growth can resume. About the time the roots get to the point top growth can resume, the grower is watering again and refreshing the cycle. In the case of low nutrition, you would normally see older leaves showing chlorosis (yellowing) and perhaps being shed, so I doubt that's in in this case. Try avoiding over-watering by monitoring moisture levels deep in the pot by using a "tell". More on that:

Using a 'tell'

Over-watering saps vitality and is one of the most common plant assassins, so learning to avoid it is worth the small effort. Plants make and store their own energy source – photosynthate - (sugar/glucose). Functioning roots need energy to drive their metabolic processes, and in order to get it, they use oxygen to burn (oxidize) their food. From this, we can see that terrestrial plants need plenty of air (oxygen) in the soil to drive root function. Many off-the-shelf soils hold too much water and not enough air to support the kind of root health most growers would like to see; and, a healthy root system is a prerequisite to a healthy plant.

Watering in small sips leads to avoid over-watering leads to a residual build-up of dissolved solids (salts) in the soil from tapwater and fertilizer solutions, which limits a plant's ability to absorb water – so watering in sips simply moves us to the other horn of a dilemma. It creates another problem that requires resolution. Better, would be to simply adopt a soil that drains well enough to allow watering to beyond the saturation point, so we're flushing the soil of accumulating dissolved solids whenever we water; this, w/o the plant being forced to pay a tax in the form of reduced vitality, due to prolong periods of soil saturation. Sometimes, though, that's not a course we can immediately steer, which makes controlling how often we water a very important factor.

In many cases, we can judge whether or not a planting needs watering by hefting the pot. This is especially true if the pot is made from light material, like plastic, but doesn't work (as) well when the pot is made from heavier material, like clay, or when the size/weight of the pot precludes grabbing it with one hand to judge its weight and gauge the need for water.

Fingers stuck an inch or two into the soil work ok for shallow pots, but not for deep pots. Deep pots might have 3 or more inches of soil that feels totally dry, while the lower several inches of the soil is 100% saturated. Obviously, the lack of oxygen in the root zone situation can wreak havoc with root health and cause the loss of a very notable measure of your plant's potential. Inexpensive watering meters don't even measure moisture levels, they measure electrical conductivity. Clean the tip and insert it into a cup of distilled water and witness the fact it reads 'DRY'.

One of the most reliable methods of checking a planting's need for water is using a 'tell'. You can use a bamboo skewer in a pinch, but a wooden dowel rod of about 5/16” (75-85mm) would work better. They usually come 48” (120cm) long and can usually be cut in half and serve as a pair. Sharpen all 4 ends in a pencil sharpener and slightly blunt the tip so it's about the diameter of the head on a straight pin. Push the wooden tell deep into the soil. Don't worry, it won't harm the root system. If the plant is quite root-bound, you might need to try several places until you find one where you can push it all the way to the pot's bottom. Leave it a few seconds, then withdraw it and inspect the tip for moisture. For most plantings, withhold water until the tell comes out dry or nearly so. If you see signs of wilting, adjust the interval between waterings so drought stress isn't a recurring issue.

Al